Standard Status Effects

For some reason, the effects of hazardous status effects, within the rules of the game, almost never change. Poison is going to slowly sap your HP. Silence is going to block your magic. Paralysis is going to keep you from moving. And the same status effects will show up in every game. It may be that gamers are so hardwired to expect certain effects from certain conditions that trying to change them is more trouble than it's worth.

As documented in Useless Useful Spells, these effects are almost always going to get used on you, thanks to the fact that they tend to linger and continue to hurt you outside of battle; unlike you, enemies always show up for battle in full health.

Games with these effects will usually feature a spell or item that cures each one individually, as well as another item, encountered later, that will cure all of them. By some inexplicable homeopathy by design, monsters that cause these effects will frequently drop the item that cures it. Don't think about it too much. Then again, anti-venom in Real Life is actually made from the venom itself so there may be some kernel of Truth in Television in that aspect.

They show up in RPGs very commonly. They might also appear in Real Time Strategy (to accentuate the "strategy" part), and occasionally in First Person Shooters and Third Person Shooters, mostly those with RPG Elements. They can even appear in platformers and puzzle games.

Many of the status ailments have equivalent Status Buffs, with opposite effects. Note that despite what is said below, any status effect that prevents a character from taking any action may sometimes disappear on any hit (especially if there are not other party members in this game), and many of them will often fix themselves after several rounds, even if they're permanent until cured in other games. There's also the case of the One Curse Limit in which one status ailment can be overwritten by a second entirely separate status ailment

Poison / Plague / Bleeding
Slowly saps your HP. In turn-based games, it will deal a set amount of damage at the beginning (sometimes end) of each turn. If the game in question doesn't automatically cure status effects at the end of each battle, this effect almost always lingers until cured, often draining a bit of HP even outside of battle with each step you take. Some games (Tales of Symphonia, Pokémon) have both regular poisons and stronger, more potent poisons that sap more health at a time. This can sometimes get hilariously out of hand, as evidenced here.

Action Adventure

 * In Castlevania: Aria of Sorrow, the Poison status reduces your stats and attack power considerably, but otherwise does no HP damage. Reversed with the Zombie soul - when equipped, you actually get stronger while poisoned.
 * In Castlevania: Portrait of Ruin, not only does poison severely lower your stats, but it also drains your health.
 * In Castlevania: Circle of the Moon, poison drains your health, but doesn't lower your stats.
 * And in Castlevania: Order of Ecclesia, poison drains your health AND lower your stats. Gee, thanks.
 * It seems to depend on the character poisoned. So far, all the strictly human characters take gradual damage from poison. Soma (the ) and Alucard (A Dhampyr) Are immune to the damage, but still get lowered stats.
 * In Light Crusader, poison switches around controls instead of sapping health.

Fighting Game

 * Super Smash Bros Melee and Brawl have a similar effect in which a flower attached to someone's head will cause constant damage.
 * Additionally, if Olimar throws a white Pikmin at an opponent and hits them, they'll take constant damage until the Pikmin is knocked off.

First Person Shooter

 * Team Fortress 2 has a few weapons that inflict Bleeding, which deals damage over time much like Afterburn, but can only be stopped by picking up a Medkit. Otherwise, it wears off on its own.
 * Borderlands has corrosion, which works like a poison. The enemy loses their shields' power and then their health over time and if they get killed by the corrosive effects, their bodies turn green and disintegrate! Enemies that have armor (man made or natural) are highly vulnerable to this effect. There is also an electrocution effect that works the same way.

Hack and Slash

 * Diablo II has a poisoned status that continuously drains health and may prevent or counteract attempts at healing. It doesn't drop a player's health below 1 HP, though mobs and NPCs are not so lucky.

MMORPGs

 * There's actually a type of MMO based around the Plague status effect, it's called a "Virtual Plague", and is used in pathology studies.
 * Guild Wars has Poison, Disease, and Bleeding. Overall, some status effects in the game get their own mechanic, "conditions". Only one condition of a particular type can be on a character at a time, and conditions effect and are effected by certain skills, separate from other buffs and debuffs.
 * City of Heroes lacks actual "poison" effects, but does offer a good deal of "toxic" damage which do basically the same thing, and actually stand in for poison a lot of the time. Their function is simple - apply additional damage over time for some time after the initial effect lands.
 * Monster Hunter uses Poison in the same fashion, with one difference - while it's damaging you, you don't recover any HP, and the red gauge is reset if you take any damage. Antidotes and Herbal Medicine are recommended if you are fighting any enemies who can utilize Poison.
 * Spiral Knights uses Poison as a debuff status: Players afflicted with it only deal about half damage and cannot heal, and poisoned enemies suffer reduced attack and defense, and will take minor damage if a heal is used on them.
 * World of Warcraft Has this all over. The Affliction Warlocks and Feral Cat Druids are desgined to take down enemies his way.

Real Time Strategy

 * War Craft 3 had both Poison and Plague stat effects, poison being kinda stuck with the Night Elves and Undead getting Plague for their artillery and Giant Mooks.
 * Introduced in Patapon 3, poisoned units will have purple bubbles floating over them. Some items can be used to prevent or cause this status.
 * Pandemic is about seeing how many people you can infect with Plague, and choosing the symptoms, infection vectors, and making it deadly without being especially noticeable.

Roguelike

 * In Final Fantasy Fables: ~Chocobo's Dungeon~, Poison always causes Chocobo to take 1 HP damage per turn, with enemies always taking 10. Therefore, Poison effects are at their most effective early in the game (or in dungeons with a low level cap). In the same game, if Chocobo drops to 0% food level, he loses HP at the same rate as Poison.
 * In Nethack, poisoning is always fairly serious. It may result in permanent or semi-permanent loss of attributes. Food poisoning is fatal unless treated very fast.
 * In Dungeon Crawl, poison slowly damages hitpoints. There is also rotting, which damages one's maximum hitpoints, leaving a far more enduring hit on one's character. There's also the curare poison which is far more deadly because it has additional effects over the standard poisoning.

Role Playing Game

 * Pokémon has a couple of variants on poison (which is the only status effect to continue to take its effect outside of battle). Normal Poison just removes 1/8 of the Pokemon's HP every turn. A Pokemon that's badly poisoned by moves such as Toxic will lose Hit Points at an accelerating rate (starts at 1/16 and increases by 1/16 each turn). Poison and Steel-type Pokémon and ones with the ability Immunity can't be poisoned.
 * Also, pre-Generation V, Poison damages Pokémon outside of battle as you walk (1 HP every 4-5 steps) until it faints or is healed. In Generation IV, the poison wears off on its own outside battle when the Pokémon is at exactly 1 HP.
 * Despite taking damage outside of battle, poisoned yet inactive pokemon don't take any damage inside of battle, probably why they removed the constant damage outside of battle in Gen V. Additionally, switching a badly poisoned pokemon out makes it become normal poison.
 * There's another status condition called "Leech Seed", which only removes 1/8 of the victim's health each turn; however, half of the amount of health lost to Leech Seed will be bestowed upon the opponent. Grass-type Pokemon are immune to this. Some have an ability called "Liquid Ooze" which will cause Leech Seed and other moves with health-draining effects to instead reduce the HP of the Pokemon that would otherwise benefit from them.
 * Speaking of Toxic and Leech Seed, in Pokémon Red and Blue both moves' HP-draining effects are controlled by the same variable in the game's memory, meaning that if both moves are in play, Leech Seed's damage goes up with Toxic's.
 * Earthbound actually has several varieties of poison - apart from the normal variety, there's also nausea (which combines Poison and Blindness), sunstroke, and (ahem) a chest cold.
 * In the early Phantasy Star games poison only prevents the afflicted character from healing damage (until PSIV, where it does damage.)
 * The later Wizardry games featured both plague and poison, but poison worked conventionally while disease operated like Cursing (see below), and was the most dangerous status effect in the game.
 * The Elder Scrolls IV Oblivion uses poison inconsistently, you can be immune to poison but certain attacks like 'poison spit' are classed as magic so effect them normally. Otherwise it is found in poisoned weapons and gas traps.
 * Final Fantasy IV introduced the smaller-but-faster HP drain in the form of Sap for the Final Fantasy series, which was used again in sequel games such as Final Fantasy V and Final Fantasy XII. It acts in a similar manner to Poison, only instead of causing damage after actions or set intervals, it drains your HP constantly. Particularly deadly if you're inflicted with both Sap and Poison. The only saving grace of Sap is that it wears off after battle (except in XII, due to the way the battle system works).
 * Final Fantasy VI had a variation of Sap called Seizure. This is notable because, unlike Poison, a bug in the game caused Seizure to hurt the undead as well as the living, with some major unintended consequences like humorous battles with undead monsters who would slowly kill themselves.
 * Final Fantasy IX had not only the standard poison effect, but also a nastier version referred to as 'Venom'. It did proportionally more damage at a time than poison, reduced MP along with the HP damage, and even prevented the afflicted character from moving (as though afflicted with 'Stop')! And this in a game where you lose if every character on the party is rendered unable to act...
 * Took a Level In Badass in Final Fantasy X, now lopping off 1/4 of your max HP per turn. More often than not, your party's healing items/spells aren't strong enough to keep up with the damage without abandoning all other actions entirely, which means that if you don't have any Antidotes or Esuna at the ready, you're dead in four turns. Good thing you can switch out your party members on the fly... except when you can't.
 * Black Sigil: Blade of the Exiled includes a standard Poison effect that drains your health a bit every so often.
 * There are two varieties of poison in the Dragon Quest series: poisoned and envenomed. The difference between the two? Poisoned characters are only damaged when walking outside of battle. Envenomed characters take damage both in and out of battle.
 * The Mario & Luigi games all have poison among their status effects; however there's a chance that the character may heal itself. In Bowser's Inside Story, Bowser can catch a cold, which has the same effects.
 * The Golden Sun RPG series has two kinds of Poison Status effects. One is called poison, which shows as cloud puffs that look like green skulls to appear as if it is leaking from your opponent's head, and inflicts about 10% of the victim's max HP in damage each time they act (which gets even more dangerous to bosses that move two or three times each round) as well as Venom Status, which shows pretty much the same as Poisoned, only it does twice the damage and instead of the skulls being green, they are a sickly-looking orange-red.
 * Standard in Shin Megami Tensei games. Notable in that it's rather easy to poison enemies (as easy as it is for them to poison you), it deals very considerable damage, and that left untreated, you will die. Sometimes it comes paired with Pestilence, an attack designed specifically as a One Hit Kill for poisoned characters.
 * The Shadow Hearts series has Poison, Deadly Poison (acquired when a poisoned character is poisoned again), Mental Break (poisoning of the mind that saps MP every turn) and Panic (saps your sanity points every turn).

Sandbox Games

 * Minecraft has a poison status of two flavors. The first one is the standard poison that reduces your health every second until the effects wear off. The poison can't kill you and only drops your health to half a heart if it gets that low, but that will leave you open to be killed in one shot by anything else in the area that can hurt you. The second flavor of poison is food poisoning, which may occur when you eat rotten flesh or eat uncooked meats. Food poisoning will reduce your hunger meter at a faster rate until it wears off.

Survival Horror Games

 * Resident Evil has had poisoning since the very first entry, requiring blue herbs in order to cure it. Some later entries also introduced bleeding out, with much the same effect and requiring a hemostat to heal.
 * Dino Crisis uses the bleeding-out variety in the first two titles.

Tabletop Games

 * In Dungeons and Dragons poison lowers your stats when you are poisoned and about a minute later Out of six stats you can only be killed by having one (Constitution) fall to zero. The others will just leave you unconscious or paralyzed. Furthermore, D&D poison goes away after the second round of damage, regardless of the victim's success in resisting its effects.
 * In 4th edition it's gone back to doing consistent damage.
 * Third Edition had a condition called "wounding" which most often caused a certain amount of damage every round (there were, of course, exceptions, and most of said exceptions would cause ability damage.) Supposedly, the damage from wounding was a result of blood loss . But, as far as gameplay was concerned, wounding in 3rd Edition D&D was really just the conventional poison status with a new name. Also, there were a few poisons whose effect was conventional (i.e. Hit Point) damage, and about one or two that could cause instant death. There was also at least one that merely knocked the victim unconscious for a few minutes. The More You Know...
 * There's another condition, Disease, that does ability damage every day until the victim has successfully made two saving throws against it. A few diseases (well, at least one, anyways - the name of it was "devil chills") required the victim to make three consecutive successful saving throws to get rid of them. And then there were a few diseases, like "mummy rot", which could only be stopped with magical assistance, regardless of how well the victim resisted them. There were even a few diseases (and poisons) which caused ability drain, which is just like ability damage except that it does not go away over time, and requires certain spells (namely "restoration" and its more powerful variants) to reverse. As should be obvious by now, D&D had a lot of different poisons and diseases, which mainly varied in what they attacked, how much damage they caused (usually, but not always, to ability scores,) and how difficult they were to resist. The common thread was the requirement to make Fortitude saves to resist them and their penchant for causing repeated damage.
 * The Sword of Wounding causes bleeding that drains 1 HP per round for 10 rounds (minutes).
 * GURPS poisons are modeled fairly conventionally, in that they damage you in cycles of a defined length, and wear out after some number of cycles. However, while poisons normally deal the "toxic" damage type, there is nothing stopping them from dealing burning or crushing damage, and they can have other effects linked to them, frequently in the form of a temporary disadvantage.
 * Pokémon: Poisoned Pokémon get a poison counter. They lose 10 HP at the end of every turn. Some attacks that cause Poison will say that the Poisoned Pokémon will take more than 10 damage each turn (usually 20 instead of 10).
 * Shadow Era has several cards that poison enemy heroes or allies, doing one damage a turn. The "Plague" card exists, but has a very different effect (takes away three resources from both players).

Third Person Shooter

 * In Kid Icarus Uprising, poison constantly deals around 1 HP of damage for some time.

Turn Based Strategy

 * Disgaea's version of poison is particularly nasty, as it chops off a set percentage of HP each turn. In the first game, it was somewhere in the ballpark of 10 to 15%, but later games ramped it up to 20%, which can be crippling without treating it.

Turn Based Tactics

 * In Odium, characters/monsters who are poisoned receive damage for three turns, receiving 15, 10 and 5 damage each subsequent turn.

Burn
A fire-based status effect, but it is otherwise a wild card that can have a range of effects (sapping the user's HP is a popular effect). If the game also features a Freeze status effect (and chances are good it already does), the two may even cancel each other out.

Action Adventure

 * Some The Legend of Zelda games have enemies that can set Link on fire. Link will lose hearts periodically while immolated, but this can be treated by rolling or some attacks.

First Person Shooter

 * "Afterburn" is the Pyro's trademark ability in Team Fortress 2. It deals damage over time, wears off eventually and can only be stopped by picking up a Medkit, diving into water, being doused by a friendly Sniper's Jarate, being doused by a friendly Scout's Mad Milk or being airblasted by a friendly Pyro. The Pyro himself/herself cannot be set on fire and thus doesn't have to worry about Afterburn. The Soldier's Cow Mangler 5000 weapon can, with a charged-up shot, inflict Afterburn and if a Pyro puffs their Flamethrower at a friendly Sniper who is carrying a Huntsman, the Sniper's arrow will be lit up.
 * Borderlands has guns and grenades that can cause burn damage to enemies and can set them on fire, chipping away at their shields and health.

MMORPGs

 * Burning mobs in Fly FF is rather strange - the 2nd tier spell does sap HP, but so slowly that it's practically worthless. The 3rd tier spell does not sap HP, but reduces water resistance. If the next attack is water, goodbye monster!
 * Thermal Shock, maybe?
 * Guild Wars has burning cause a large amount of health degeneration (7 arrows vs. 4 for poison and disease). Burn effects usually last for shorter times to compensate.
 * Monster Hunter calls this Fireblight, but if it looks like burning, smells like burning, and hurts like burning, it's burning. Expectedly, you can snuff it out by rolling on the ground or going into water. Neat, since the Qurupeco and the Rathian can be fought in Moga Woods after defeating them in quests.
 * Spiral Knights has this as the standard life-draining status. Works the same way for both player and enemy, although one should avoid using Fire inflicting attacks when Oilers are about.
 * Fire Mages and Destruction Warlocks in World of Warcraft both get abilities that tick away at the targets HP.

Real Time Strategy

 * Starcraft uses this in conjunction with Damage Is Fire for Terran buildings, at 25% health, they start to burn down automatically.
 * Patapons (and enemies) can get burned in all 3 games.

Roguelike

 * In Dungeon Crawl, sticky flames (cast as a spell of breathed by a dragonoid) will damage the burning character quickly while damaging their scrolls. Stepping into water cancels the flames. Burning sheeps have an unique property - they may spread the fire to other sheep.

Role Playing Game

 * Pokémon lose 1/8 of its health a turn and also have their Attack halved while on fire - due to physical burns all over you, you may suffer from weakened attacks. Fire-types and ones with the ability Water Veil are immune to burn. The ability Heatproof reduces the damage taken from burns, and the ability Guts instead raises attack while burned.
 * Strangely enough, there is a Water-type attack (Scald) and an Ice-type attack (Ice Burn) that can inflict this.
 * In the card game, Burned Pokémon take 20 damage between turns if a coin flip lands on tails.
 * Burn in Final Fantasy IX actually kills a burned player when they do something.
 * Burns in Odin Sphere continuously cause damage and will wear off after walking a certain length of time, depending on the severity of the burns. Also, simply being in the Volkenon Lava Pits will sap HP unless a Cooler potion is used. Having a certain piece of equipment will prevent both of these effects.
 * In Radiata Stories, characters who are burned will act normally but will occasionally jump up in pain from the flames until removed.
 * In some of the World of Mana games (such as Secret of Mana), being on fire results in continual, persistent damage in which your characters can't do anything until the flames stop.
 * Characters can be set aflame in Black Sigil: Blade of the Exiled. It acts similarly to Poison, draining health over time, but generally wears off after a while whereas Poison tends to last the whole fight unless cured. Not so bad in itself, but it can actually deal good damage should you be Poisoned and on fire.
 * In the Mario & Luigi games, Burn deals minor damage every turn and immobilizes the affected character/monster. If the bros are on the receiving end, the affected bro won't be able to jump, as he frantically tries to put out his trousers.
 * "Ignite" in some Kingdom Hearts games, which is functionally the same as poison, chipping away a fixed amount of the victim's health periodically. It's represented by the player character being literary set on fire. It's particularly amusing to see Axel with the effect, given that he's a fire user who could absorb fire damage in boss fights against him.

Tabletop Games

 * A normal damage type in GURPS, "burning", will set human flesh on fire if it deals at least 30 points of damage in a single hit. That much damage would normally kill a character right out, but if it's dealt to a limb, the limb is now disabled and you're on fire. Take 1d6-1 damage per turn.
 * Dungeons and Dragons has magic that causes fire damage over time, such as the Forgotten Realms spell Shroud of Flame.
 * Several cards in Shadow Era can set enemy allies and heroes on fire, doing one damage a turn.

Third Person Shooter

 * The Burning status in Kid Icarus Uprising basically has the same effect as Poison, but deals slightly more damage in exchange for wearing off faster.

Turn Based Tactics

 * In Odium, characters/monsters set on fire burn for three turns, receiving 15, 10 and 5 damage each subsequent turn.

Paralyzed
These characters temporarily won't be able to move. Unlike in Real Life, paralysis is usually one of the shortest-lived effects -- it'll wear off after a turn or two. Sometimes, there's a randomized chance of shaking the effect for a turn.

Action Adventure

 * Some Zelda games have enemies with electrical attack that will zap Link either through contact or through electrified projectiles. Link will be unable to act until the electrical shock disperses - in The Legend of Zelda Skyward Sword, it is possible for Link to take an electrical attack, spasm uncontrollably, and be smothered by sinksand, in that order. Watch your step, and deal with electrical enemies before committing to a crossing.

Fighting Game

 * In the Super Smash Brothers games, characters can be stunned. This mostly happens by a character's shield breaking (they held it up for too long or got hit by too many moves), but it can be caused by other things as well (such as items or Mewtwo's Down B). Interestingly, if stun is caused by shield breaking, then before the actual paralysis, a character is launched a bit into the air with a chime that sounds like glass shattering (Jigglypuff goes the highest, and it's very possible to die this way). After crashing on the floor, they get up and then act dizzy. Button Mashing is required to get out of it faster, and it lasts longer the more damage a character has.
 * Characters can be stunned in the Street Fighter series if hit with a large number of attacks without blocking. Street Fighter III even has a stun gauge that induces stun if filled.

MMORPGs

 * The Fly FF Psykeeper can use Satanology, which increases in duration based on his Int stat, eventually lasting longer than the cooldown period. In Pv P, a Psykeeper with enough Int. can cause a melee class to be demolished!
 * Guild Wars avoids this confusion, replacing it with the simple and logical "knocked down," which is exactly what it sounds like.
 * City of Heroes feature a pretty clear "stun vs. immobilize" mechanic, only stun also tends to limit the speed at which stunned characters can move at down to pretty much the slowest a character is allowed to move. Still just about fast enough to move out of a fire burning under your feet, but not nearly fast enough for you to get anywhere, or get away. Immobilize on the other hand allows the character to fight, either using ranged attacks or meleeing with an enemy close enough, but cannot move from their position.
 * The game also features "Hold" powers, which prevent the target from being able to do anything at all and making them totally helpless.
 * Monster Hunter uses Paralysis as you might expect, but it plays by different rules based on the victim. Player characters recover when attacked by anything (a smack from a fellow player or Cha-Cha will remove it), while monsters remain paralyzed until [A] the effect times out or [B] the monster dies. Pounding a paralyzed monster's face in will not remove paralysis unless it goes into Rage mode.
 * Spiral Knights has the Shock status, which causes the afflicted to be paralyzed for a second (and take damage, although this is blockable) due to spasms from electricity going through their bodies. This is probably the most notorious status effect later on, due to enemies being able to constantly reapply the status leading to death via infinite spasm-lock.

Roguelike

 * In Nethack, paralysis prevents all actions and lasts for an uncomfortably long period of time. "Killed by a newt, while helpless" (i.e., while paralyzed) is a common ending for many a new adventurer.

Role Playing Game

 * In Pokémon, Paralysis is permanent until cured, cuts Speed by three quarters, and has a 25% chance of preventing an attack from working.
 * In the card game, Paralyzed Pokémon can't attack or retreat during its owner's turn. It's cured at the end of that turn.
 * Some Tactical and Massively Multiplayer RPGs will split Paralysis into two types: one that keeps the victim from moving around the map (often referred to as Immobilize), and one that allows them to move, but keeps them from actually doing anything (often referred to as Stun, but it is often also combined with Immobilization).
 * Case in point, Final Fantasy Tactics, at least the original, has "Don't Move/Immobilize" And "Don't Act/Paralyze" which are exactly what they sound like.
 * Shin Megami Tensei has Stun, which has an excellent chance at stopping the afflicted party from moving at all. Another version is Paralyze, which may be the result of an Electric attack that is not repelled, absorbed or nulled: the victim remains convulsing for the rest of the turn, leaving it defenseless and open to physical revenge (all attacks it receives while paralyzed count as Criticals, netting the enemy, either the player or the computer, more Press Turns).
 * Depending on the game, paralysis in the Tales Series either prevents action until cured, prevents action for a short time, or perhaps most annoyingly, causes the afflicted character to flinch at random intervals.
 * Earthbound's version doesn't let you make basic attacks, defend, or access your items; but you can still use PSI. Also an exception, it will last out of battle until you talk to a Healer at a hospital or use PSI Healing Gamma/Omega.
 * A Paralyzed character or enemy in Black Sigil: Blade of the Exiled will be totally unable to move or act, as their time bar is frozen for the duration of the effect.
 * Paralysis is relatively rare in the Dragon Quest series, but it can be particularly annoying, especially if the paralyzed person is the only one who can cure it with magic, or if you don't have moonwort bulbs. More common are "shock" attacks that cause a character to lose their turn.
 * In Baten Kaitos: Eternal Wings and the Lost Ocean, paralysis immobilizes a character, preventing them from attacking or defending. It's every bit as dangerous as it sounds, and it's the main contributor to the Angel of Darkness' status as That One Boss.
 * Origins replaced it with Stun, which worked a bit differently from most paralysis; the character could move and attack, but any damage resulted in instant knockdown.

Tabletop Games

 * Dungeons and Dragons used Hold Person and its variants for this, and some variants of the game treat you as being helpless for the duration, leaving you vulnerable to being killed by a Coup De Grace. Fourth Edition D&D has the Stunned condition, which flat out means you cannot move or take any actions at all and that you grant combat advantage to any enemies near you.
 * Third Edition characters could also be stunned (with basically the same effects as 4e), as well as Dazed, which prevents the character from taking actions but doesn't hinder his defenses.
 * Several in GURPS: Stunning is a common side-effect of major wounds, being knocked down, and the Affliction advantage. You have to make a health roll to break out of it, and until then, you can't take any action. The Binding advantage doesn't knock its victim out, but holds them in place, meaning they have to win an opposed contest of strength with whatever supernatural gobbledygook is keeping them down, or else they can't move. And the Terror advantage forces your victim to make a Fright Check, which will probably inflict Stunning, but maybe also drive the victim crazy.

Third Person Shooter

 * In Kid Icarus Uprising, being paralyzed slows you down considerably, and often halts movement altogether, though it wears off quickly.

Turn Based Strategy

 * Nippon Ichi games' paralysis stops movement (but not actions) and reduces the affected character's speed to 1 (meaning that every attack against it automatically hits). An exception is made for Phantom Brave, where paralysis halves speed (which affects how many turns the character gets) and movement range.
 * Note that, since fist weapons (from game 2) and guns (game 3) also run off speed for their damage formula, this effectively cuts their attack power in half.

Sleeping
They won't be able to move either. This effect usually lasts longer than paralysis, sometimes indefinitely if you don't cure it. Fortunately for you, striking a sleeping character will usually wake them up (although sometimes it must be a physical attack). One of the more nonsensical status effects, generally -- sleeping characters will often sleep standing up, sometimes not even changing their normal stance or battle movements, and they won't respond to the sights or sounds of battle. In addition, you can cure sleep by going to a Trauma Inn and... sleeping? Perhaps you're just waiting to wake up...

Fighting Game

 * In Super Smash Brothers characters can be put to sleep. Interestingly, it can only be caused by a pokemon, either one from a Pokeball (Bellossom, Togepi) or it is a cause of Jigglypuff's Up B move, sing, which causes sleep in her games. It usually only lasts for a couple of seconds, but it's possible to put characters in sleep lock where they doze off immediately after waking up using the aforemented pokeball pokemon. Jigglypuff however, needs to time her move so they don't wake up before she stops singing

MMORPGs

 * World of Warcraft has potions that make you sleep in a healthy way, restoring health and mana rapidly. A more traditional Sleep effect is also in place, but can generally only be used on animals (and druids in animal forms). For players that is, monsters with the spell have no problems putting you to sleep.
 * Before it got nerfed, the 'x% chance per received hit to put melee attackers asleep for 30 seconds (any damage will wake them up)' level 30 leather chest, obtained with crafting, was great fun in pvp and handy in pve. It used to put anything to sleep, regardless of level difference. It was very useful in the right situations for tanks, ranged classes and druids for some extra crowd control. It might still be useful now, but it's not as powerful as it used to be. Limited to sleeping enemies under lvl 55 and only 5 or 10 seconds sleeping time i checked.
 * Druids get the ability Hibernate, though it only works on animals and dragonkin.
 * Achaea characters sleep lying down, but can still see and hear almost everything going on around them while asleep. Sleep is used as per usual to regain hit points and sometimes to control opponents in combat - unusually, characters get tired, yawn and spontaneously fall asleep if kept awake for too long.
 * City of Heroes has a pretty standard sleep mechanic, in that characters put to sleep will sleep standing up, be unable to act, and stay asleep for a comparatively really long time. Sleeping characters can be woken up by dealing damage to them, which can create tension in teams when wide-area sleeps are followed by wide-area fireballs, or be woken up by healing them. Basically anything that alters hit points.
 * Monster Hunter plays Sleeping a bit differently. Players have a brief moment to chug an Energy Drink before they go wholly to sleep, while monsters drop immediately. Any damage at all will wake a sleeper, but crafty players will set bombs or traps without disturbing the monster during this time, due to the monster taking triple damage from all sources on the hit that wakes them from Sleep. With this knowledge, Greatsword + Sleep agent (Drugged Meat, Sleep Knives, or another player armed with a Sleep weapon) = GOTCHA BITCH!
 * Spiral Knights has the "regenerate health while asleep" version of this status, although the reason you'll see the status is if someone needs to clear space for a better status vial, due to the only area with sleep-inducing monsters not being in the game (as of 5/15/11)

Real Time Strategy

 * In War Craft 3, neutral monsters sleep during the night, making them easier to ambush. Since there's no separate 'sleeping' animation, trolls can actually do backflips in their sleep, just as they do when awake.
 * The Dread Lord heroes also have a 'sleep' skill that does what it says on the tin.
 * Patapons (and enemies/bosses) can be put to sleep with the right units and weapons, although it's rare to see a boss fall asleep.

Role Playing Game

 * Pokémon uses this, which prevents attacking for 1-7 turns. Pokemon with the abilities Insomnia or Vital Spirit are immune to this. Amusingly, you can wake them up with a reusable flute item in some versions, and in Coliseum you can just yell at them.
 * And then there's the move Rest, which forces your Pokemon to sleep for two turns (not counting the one used doing it), but fully restores its health and removes other status effects. It's a key component in many tournament players' lineups.
 * There's also a move called "Snore" that could be used while a Pokemon was asleep. There's also "Sleep Talk" where the Pokemon will use a random move while asleep. Either one of these will likely be found on a Pokemon that knows Rest.
 * Or they'll be holding a Chesto Berry, which cures Sleep immediately; this pretty much lets the Pokemon itself use a Full Restore (full HP recovery and wipes any Status Effects).
 * In the card game, sleeping Pokémon can't attack or retreat. Between turns, its owner flips a coin. If it lands on heads, the Pokémon wakes up.
 * Lost Kingdoms II had this, but the target in question stops moving and recovers health slowly. Plus, as to add some realism, Tara kneels down while asleep. The sequence she does to fall asleep and wake up immobilizes her, as if playing with Tara wasn't hard enough as it is.
 * In Shin Megami Tensei Nocturne, you will actually beg to be put to sleep. It immobilises you but restores HP AND MP. Anyone who plays this knows that mana is like gold dust in this game, what with the critical macca shortage one starts experiencing early on due to having to pay considerable sums of money that increase the more you need healing, as opposed to the typical '100 gil full rest'. Of course, this is only for the first part of the game, until the spellcasters doing this couple this with Eternal Rest - an unavoidable One Hit Kill which only will kill sleeping people.
 * In Digital Devil Saga, Cielo has a move tailored to exploit his weakness to ailments: Null Sleep, which will effectively null all attacks he receives when he's sleeping. Very useful against the Bonus Boss.
 * Earthbound has this, rendering the character uncontrollable for several turns. It breaks with an enemy attack.
 * In Black Sigil: Blade of the Exiled, being put to sleep stops a character from acting for a few turns, but being attacked will wake you up, physical or magical. Tends to be undone by angry monsters before you need to bother curing it, unless the only creatures present like reinflicting Sleep over and over.
 * Sleep in the Dragon Quest series tends to last for several turns, and it usually cannot be interrupted by physical attacks.
 * In almost every Final Fantasy game, sleeping could be cured with brute force, so you could have your Squishy Wizard or White Mage smack the sleeping characters for little damage and wake them up.
 * In Final Fantasy XI, since you can't attack other PCs, Cure spells wake an ally up instead. Even Cure I will do.
 * Of note: In Final Fantasy X, monsters afflicted by "Sleep" actually do curl up and go to sleep on the screen, rather than just having "ZZZ" over their heads. The developers went above and beyond, there.
 * Lunar the Silver Star puts a variation on the "sleep" status by making whomever is hit in sleep state take double the damage of any attack.
 * Appears in the more recent Kingdom Hearts games, in the usual style of being unable to do anything until struck or more rarely, waking on one's own. Victims use the same animation they would as if they were stunned.
 * Appears in Xenoblade Chronicles, where the victim is unable to act for a lengthy period of time, and is guaranteed to be critically hit, but will wake up upon taking damage.

Sports Game

 * One powerup in Backyard Football makes the other characters fall asleep, allowing the player with the ball to easily score a touchdown.

Tabletop Games

 * Dungeons and Dragons has rules for being woken up either by the noise of battle or by an ally shaking you. Magical sleep is extra deep so the noise won't wake you.
 * Also, if you're damaged during sleep, instead of waking you up, it most likely kills you -- sleeping characters are considered helpless and are thus vulnerable to being CDG'd.
 * GURPS Afflictions can incapacitate their target in a variety of ways. To get the effect that "sleep" usually has in RPGs, you want to Daze them; Unconsciousness makes them fall over, and they can't be woken up until it wears off, other magic effects notwithstanding.

Turn Based Strategy

 * Disgaea's version of sleep immobilizes the character. Said character can be woken up with any attack, but in return the attack will be treated as a Critical Hit.

Silenced
They won't be able to use magic. This is a holdover from the classic fantasy trope that you have to say magic words (sometimes rhyming ones) or chant a spell's name in order to use magic, so being muted would logically prevent that. However, the trope often gets carried over into games where magic clearly doesn't work like that, or isn't even present (like in Super Mario RPG: Legend of the Seven Stars -- why would being silenced prevent Mario from being able to jump?) Particularly hilarious when the enemy silences a Heroic Mime. Games with voice acting will sometimes have the characters still be able to talk even while "silenced". (Skies of Arcadia is a major offender here.) One is forced to wonder if some game designers, Japanese ones especially, ever looked up what "silenced" translates to.

MMORPGs

 * In World of Warcraft, Warlocks additionally have the so-called "Curse of Tongues", which slows down casting and makes the target speak Demonic -- in the ingame chat! -- as long as it lasted.
 * The Silence skill is also one of the Dark Ranger's ability's in Warcraft3.
 * Shadow Priests get a Silence spell as well... Although I'm not sure how a Silenced enemy is prevented from casting spells, but not from yelling for help.
 * Marksmanship Hunters get an ability called Silencing Shot. Guess what it does.
 * Since Cataclysm, pretty much everyone can interupt and silence a casting target.
 * In Ace Online, I-gears can Silence enemy gears and block them from using their skills.
 * Guild Wars has a particularly nasty status condition called Dazed. Characters suffering from it take twice as long to cast their spells and said spells can be interrupted by any attack that hits them.
 * "Interrupt" is a mechanic which does Exactly What It Says On the Tin and can be thought of as active Silencing: it requires very good timing, but a player with a bar full of interruption skills can prevent their enemies from successfully casting any spells. Doing so is known ingame as "shut-down", and there is an entire class devoted to it. (Ironically, this class barely has any skills which apply the Dazed condition. They don't need it.)
 * In Ragnarok Online, when you're Silenced your character gets a speech bubble with Visible Silence and you can't use any Skills--magical or physical (apparently skills require you to call your attacks?). For classes that rely mostly on magic like Wizards and Priests until this wears off you're screwed... especially if your Priest, who can Cure it, is silenced.

Real Time Strategy

 * Silence is a fairly common debuff in League of Legends. It prevents the use of all abilities, including items with active effects and summoner spells.

Role Playing Game

 * You can tell when characters in Final Fantasy VII have been silenced because they have a large speech bubble filled with Visible Silence over their heads.
 * Ward from Final Fantasy VIII and Garnet/Dagger from Final Fantasy IX lose their voices for segments of the game, and can still cast magic (though, during that segment, Garnet will occasionally fail to do what you ask her to do). They're also still susceptible to the Silence status ailment. Go figure.
 * They seemed to have learnt, seeing how in Final Fantasy X, being silenced prevents your character from using magic, abilities and saying their victory quotes at the end of the battle.
 * In Final Fantasy VI a certain boss whistles for help at one point as part of his AI script (it's not a listed ability). The game even plays a whistling sound effect. Silencing the boss (not that you can at that point without cheating) prevents this.
 * Also used somewhat intuitively in Wizardry 8 in that, of the four schools of magic, silencing does nothing to stop alchemists from using spells ("Sure, I can't talk, but that's not stopping me from throwing explosives"). However, while it makes sense for Wizardry and Divine spells (which require incantations and prayers) to be affected, Silence will also, bizarrely, affect Psionics...
 * In Icewind Dale, one of the first mini-bosses is an evil cleric who has things to say when she dies. Is she is Silenced at the time, the game is locked in a during-event state and it is impossible to save the game at all.
 * Persona 3 refers to this as Panic, where a character, well, panics and can't concentrate on using magic or summoning their Persona.
 * The main series also has the ailment, as Mute.
 * Wild Arms games calls this "Misery" and it affects all Force abilities.
 * "Stopspell" from the first Dragon Quest games does Exactly What It Says On the Tin, blocking your opponent from using his spells. It can be a lifesaver if you're facing a spellcasting enemy and want to stop him from using his nastier magic (particularly if he can also cast Stopspell) on you. It's known as "Fizzle" in the recent translations, and it affects a whole group of enemies to boot! Needless to say, it gets annoying when enemies start tossing it at your entire party.
 * Exile has Dumbfounded, where the character forgets their spells. This is to avoid the whole "Why can they speak?" issue.
 * Some enemies in Earthbound can disrupt your senses, making you unable to use PSI.
 * In Mother 3, if you get inflicted with "forgetfulness", you won't be able to use any skills/PSI.
 * The game also has a ridiculous variant, fleas.
 * The Elder Scrolls IV: Oblivion enemies will often cast a single spell after being silenced and then attack you with a weapon, this can be due the fact silence only effects spells, not scrolls or greater/lesser powers.
 * Black Sigil: Blade of the Exiled - Silenced characters cannot cast magic, but can still use physical techniques that consume SP as well as normal attacks. Combo-attacks are disabled if the Silenced character's half of the attack is magical based as well.
 * Chrono Cross has element-specific silencing; the Anti- elements will prevent one character from using that color element until battle ends or the status is removed, and there's one type of element that can seal all elements.
 * The Arts Seal status in Xenoblade Chronicles prevents you from using any attacks or abilities other then basic auto-attack.

Tabletop Games

 * Dungeons and Dragons has the Silence spell, which works exactly as it says, creating a spherical area of total silence. Unlike many other examples, however, this does prevent all forms of sound including normal speech, sounds of battle, etc. and even stops sonic attacks that would go through the area, even if they were cast from outside the area. It also doesn't prevent spellcasting that has no verbal components including, notably, all of the Psionic classes. There's also a status condition called Deafened, which imposes a 20% failure chance on verbal spells - on the reasoning that being unable to hear yourself speak makes it slightly more difficult, but not impossible, to control your voice.
 * GURPS has both Mana Damper and Neutralize. The former acts on the mana level of the area, perhaps an area consisting of only one person (if you take appropriate enhancements). Neutralize disables an advantage; this is something innate to the character, rather than a spell they learned. Neutralize is meant for use against psionic powers, which are ostensibly different from magic in that they're something a character does entirely with their mind, not requiring mana or magic words or any of that stuff; but if the GM allows it, there's nothing really stopping you from using Neutralize to cancel a sorcerer's ability to generate mana.

Turn Based Strategy

 * However, in Final Fantasy Tactics Advance, being silenced will only block off abilities that would intuitively require speaking - magic spells, but also abilities like "Cheer" and "Advice."
 * Its cousin, Addled, blocks everything, but it barely ever shows up.
 * Silence also blocks off certain physical abilities like the Warriors Shout abilities. However, being silenced never actually makes characters or monsters unable to talk.
 * In Disgaea, being hit with Amnesia from an attack (marked by red question marks floating over the victim's head) will result in the victim being unable to use anything other than regular attacks.
 * In Phantom Brave and Makai Kingdom, it prohibits all but a weapon's basic non-MP-using attack. The same can be achieved by standing on Silence Geo Effects in Disgaea.

Blindness
Either totally stops or sharply decreases the accuracy of physical attacks, much as Silence does for magic. In the Final Fantasy games, this often has a strange tendency to not be a very large accuracy drop... (Well, if your enemies are all standing neatly in a row waiting patiently to be attacked...)

MMORPGs

 * Ragnarok Online has blindness not only decrease accuracy and dodge rate, but also limits the actual area a player can see.
 * Ever Quest had blindness affect a player far more than a monster by making it impossible for the player to see by turning the visual field black (and if you were using the interface that had menus overlap the visual field, you couldn't see the menus either). Interestingly, though, you could still do anything as normal, such as cast spells, select targets, etc., just you had to be able to do it without seeing (i.e. memorize the location of the mouse and try to navigate through menus without actually seeing them, or use macros).
 * Guild Wars has this condition as well, giving physical attacks a 90% chance to miss.
 * If there's one thing that rogues in World of Warcraft are known for, it's that they can be righteous dicks. Especially with their ability "Blind" which, in this case, renders the user completely useless and wandering around for a good 10 seconds. Any damage will cause the the afflicted character to "see" again by knowing where their opponent is and cancel the wandering effect.
 * City of Heroes does have a "blinded" effect, but all this typically does is reduce player perception, making enemies either completely invisible, or only visible when they are very close to the character. However, powers that apply blind effects typically come with accuracy-reducing effects anyway, so it's relatively safe to say that blindness makes seeing and hitting enemies harder. Oddly, it does not make seeing TERRAIN harder, causing many an instance of running into a seemingly empty, clearly visible room, only to be insta-killed by enemies which were there, but you just didn't see.

Real Time Strategy

 * In Starcraft: Brood War, the terran Medic gan use a flash grenade to blind enemy troops permanently. This becomes useless if you have the "Reveal Map" cheat activated, or if the unit has a spotter.
 * However when used on a 'Detector' it becomes unable to see invisible units that aren't in it's now limited field of vision, even with a spotter.
 * Some champions in League of Legends can apply the "Blind" debuff on enemies, causing all attacks to miss. It's usually short-lived, but it can mean a world of difference when facing an enemy that relies heavily on basic attacks to deal damage, especially if they also rely on lifesteal to maintain health.

Roguelike

 * Nethack does interesting things with blindness; when the main character is blinded, in addition to the usual effects, the player can't see any enemies on their screen -- unless they have the "Telepathy" trait, in which case they gain the ability to see virtually all enemies on the map. There's even a "Blindfold" item which is supposed to be worn by telepaths...
 * Blindness also prevents the character from seeing what's on the ground, forcing them to use their hands. Woe be to the adventurer who just killed a cockatrice and isn't wearing gloves! Scrolls can't be recognized or read (instead of "a scroll labeled AXLDFKJ" you just get "a scroll"), gemstones are all "stones", and in general a blinded character will learn that The Dev Team Thinks of Everything.
 * Other Roguelikes tend to limit the area which the player can see, though it is still possible to attack and hit enemies in the darkness.

Role Playing Game

 * This is one of the status effects in Kingdom Hearts 358/2 Days. It causes most physical attacks to miss, though magic attacks are unaffected. For who knows what reason, even   is affected by Blindess, even though.
 * In later titles, it limits your field of vision to a tiny circle around your character. In the case of enemies, it just makes them attack in random directions at random times.
 * And on the opposite end, games like Wizardry also include characters with terrible directional hearing. How the heck else can one explain the tendency to be surrounded by enemies and accidentally shoot someone standing right next to you?
 * Final Fantasy VI unintentionally averts this trope in the original with a glitch making the evade stat useless, thus making blind, which makes evade 0... completely harmless. And, thus, the item that prevents blindness, Goggles Do Nothing
 * Well, actually, there is still ONE thing Blindness does: Strago can learn any Lore he sees (whether or not he survives seeing it), so if he can't see anything, he can't learn any Lores.
 * Earthbound wins the award for the most ridiculous name for this status effect, which it calls "uncontrollable crying".
 * Radiata Stories actually blurs and pixelates the screen when your character is afflicted with Blind, so neither the character nor the player can see what's going on.
 * In the Mega Man X Command Mission, which replaces standard statues effects and spells with robotics-themed counterparts, not only does this status reduce the character's accuracy, but their evasive ability as well (can't dodge what you can't see, right?).
 * In the Pokémon games, there are moves that reduce the opponent's accuracy, which usually involve throwing something in their eyes. Though like most stat modifications, this is canceled as soon as the victim is switched out or otherwise leaves the battle.
 * Since the first three Final Fantasy games factored in accuracy in damage calculation (since number of hits per attack is one of the more important factors), this status effect resulted more in dealing less damage.
 * In Black Sigil: Blade of the Exiled, Blind results in a pretty standard reduction to your accuracy. This can be especially frustrating when it hits the Designated Hero before he can use any magic.
 * Squall Leonhart and Seifer Almasy, whose weapons sports Hit% 255, is utterly unhindered by Blind. They're that Badass.
 * In the Dragon Quest series characters can get "dazzled" from a variety of moves. It can be very frustrating as the only cure is patience.
 * In Baldurs Gate, Blindness offers a -4 penalty to armour class and THAC0, and reduces sight range to 1. In layman's terms: You hit worse, you get hit easier, and targeting anyone outside of melee range, with whatever weapon or spells you have, is impossible. Enemy mages and archers struck by this spell cast defensive spells and then stand dumbfounded unless you charge them in melee, since their AI sticks in them into an illegal behavioural mode (i.e. try to target foes at range, find you can't due to the spell). Several enemies completely disregard this penalty however.
 * Golden Sun has the Delusion status, which reduces the affected creature's accuracy.

Tabletop Games

 * A possible effect of a GURPS Affliction. Generally, this gives a -8 penalty to all attacks, which is enormous in GURPS terms.

Berserk
Describes a character who can't be controlled, loses all of its abilities except its basic attack, and whose attack power goes way up -- though at least berserked characters are still attacking the proper side, unlike Confused or Charm. Arguably, this can be exploited to one's advantage, depending on whether the victim is a fighter or spellcaster -- some games even classify it as a positive status effect.

MMORPGs

 * There are lots of World of Warcraft mobs that go berserk when their hit points fall below a certain percentage. Conveniently, they're often called "Foo Berserkers".
 * Some ogres have a particularly silly version of it: it increases their attack power, but also slows their attack speed so much that it's basically canceled out and slows them down so much that ranged classes have an even easier time dealing with them.
 * Many bosses have a so-called 'hard enrage', where after a certain period of time their damage goes through the roof, killing everyone in seconds. A 'soft' enrage does the same thing except here the boss gradually gets stronger throughout the fight until it becomes impossible.
 * Additionally, warriors have both a talent called Berserker Rage and a fighting mode called Berserker Stance. The warrior Berserker effects will increase damage done but also damage taken, and a berserk warrior is immune to Fear spells.
 * Feral Druids get an ability literally called Berserk. Depending on the form it's used in, it either halves the cost of your abilities (Cat) or removes the cooldown of one ability (Mangle-Bear).
 * I-gears from Ace Online have Berserk as their other signature attack, apart from frenzy.
 * Lord Knights in Ragnarok Online can purposely go Berserk. It ups their attack speed, hit chance, and overall attack power for the duration. Unfortunately, their defense drops, and Berserk mode slowly zaps away their HP. Oh, and they can't even chat with guildmates until it wears off... or they die, whatever happens first.

Role Playing Game

 * Many Final Fantasy games have the player capable of casting berserk on enemies as well as themselves. Perfect for preventing weak enemy mages from casting their powerful spells.
 * Final Fantasy XII treats Berserk as a positive status trait. It's cured by Dispel, the positive effect remover, enemies often use it on themselves, and it speeds up attacks greatly. Just don't use it on your lead character, or you won't go anywhere until it wears off.
 * Final Fantasy X 2 has an entire class devoted to the spell Berserk (ala The Berserker Dressphere), the spell in case can only be cast on the caster.
 * Final Fantasy IV has the berserk white magic spell, which does just what it says above. In addition, the "Avenger" two-handed sword, when wielded by Cecil, causes him to go into a permanent Berserk-mode, and the ultra-rare Pink Puff enemy has a "dance" that both changes the battle music and causes the whole party to go berserk.
 * Final Fantasy V had the Berserker job. Simply being that job makes a character constantly berserk, and one of the abilities you can learn from that class allows you to carry that trait over to other jobs. Interestingly, they still have MP, allowing them to wield runic weapons at full power (they drain the user's MP).
 * Final Fantasy VI didn't have that much use for it, but one particularly nasty boss becomes trivial if Berserked-instead of hammering the party with powerful magic, he attacks for pathetic damage.
 * Berserk is a status effect in the Final Fantasy Tactics games, but it's rarely especially useful for either the player or enemies to inflict it on each other. Final Fantasy Tactics a 2 featured the Berserker class, which had the ability to make itself Berserk if you felt like it.
 * In the Persona series, Berserk actually is a negative status effect, since it also halves the afflicted character's defense power. And of course, an enemy's ailment spells will nearly always hit you while yours rarely work. So if your dedicated healer, who usually has the lowest max HP of the group, is hit with Berserk...
 * However, there is a boss in the game whose strategy revolves around Berserking your characters and decimating them with powerful physical attacks. But the boss is also weak against one of the three physical weapon types, specifically, Pierce! So equip your Main Character with a spear, bring Aigis, Ken, and Yukari and then watch the boss get torn apart. One is advised to keep at least one person free of Rage, however, because the boss also uses Megidolaon, and you need someone who can heal.
 * For bonus points, that boss is the final Tartarus boss. What a way to end the dungeon.
 * Shin Megami Tensei Strange Journey has the Rage ailment. You lose all control of the affected members of your party. You gain great attack power, but begin uncontrollably attacking anyone in the battlefield. Maybe it can kill the enemy, yes, but more likely to wind up killing your own party. Did I mention there's almost no way to cure it except extremely rare items? And that the Final Boss also has it?
 * The series also has a form of Practical Taunt which greatly boosts enemies' Attack while dropping their Defense to nothing.
 * Digital Devil Saga has a boss fight against Ravana, who uses an attack called Hunger Wave. This causes the party to sink into a form of Berserk that is actually gnawing hunger - either they lose health from starvation or turn on each other. None of your items or skills can cure it; only Sera's song can do so. Fortunately, she's watching the battle and will run in at the start of any round where a party member is suffering from it, using her song to cure one member of the party; unfortunately, since she has no combat ability, she can't risk staying for longer than necessary, and thus can only cure one party member at a time.
 * Pokémon has several attacks that work like a temporary version of Berserk, causing the user to automatically keep using that one move repeatedly for a certain number of turns (somewhere from 2 to 5, usually randomly chosen). There's also the move Encore, which forces the 'opponent' to use the same move they used last repeatedly until it wears off.
 * In the first generation games (Red/Blue/Yellow), the move Rage made the user go mad, refusing to do anything else (even let you use items or switch it out), and getting angrier and therefore stronger every time the user took damage. Strangely enough, only one PP was used up starting this--subsequent attacks (also called Rage) didn't use any PP. It was not a very good attack. However, later versions changed it so that Rage was just like most other attacks and simply gained more power as the user took damage.
 * The second generation games (Gold/Silver/Crystal) introduced Swagger, a move that increased the opponent's attack power and confused the opponent, thus increasing the amount of damage they take when they hurt themself. They also had the Berserk Gene item, which is found where Cerulean Cave used to be, and does the same thing as Swagger to the Pokemon that uses it.
 * Also there is the move Taunt which prevents use of non-damaging moves.
 * An unused badge in Paper Mario's ROM data gives Mario this effect. His ATK increases by 2, and he automatically attacks with either a standard jump or hammer attack.
 * Shadow Hearts has a slightly different version of Berserk that works a little bit like the Confuse status (see below). It's not a status that can be directly inflicted; however, stay in battle too long and your characters will go Berserk once they run out of Sanity Points. Also, if you want the protagonist to learn his most powerful abilities, you have to let him go Berserk.
 * In Black Sigil: Blade of the Exiled, a Berserk character doesn't get any significant boost to their power, but cannot be controlled and will physically attack as they see fit. Most of the time, they manage to attack enemies, so it's not so bad until you find monsters that love to inflict Berserk while only being vulnerable to magical damage.
 * Breath of Fire III: While not so much a curable status effect, having Rei will cause him to become much stronger but uncontrollable, having him only attack physically, and becoming increasingly likely to attack allies every turn he stays in that form. Luckily, you can easily fix this by using Influence, which is normally pretty useless. With it, however, you can use Influence to target a boss monster and have Rei only attack them for the whole fight.
 * In Mario & Luigi: Bowser's Inside Story, Bowser can be get hit with the Fury ailment if he takes too many hits (complete with him Turning Red and steaming up). He's still perfectly controllable, but his Attack goes up and his Defense goes down.
 * Given that it's possible to avoid every single attack with good timing, this can easily be Cursed With Awesome
 * Suikoden III treats Berserk as a buff more than a Standard Status Effect: Berserked characters have amped-up attack and the rune that gives them the amped attack takes up a slot and...that's it. They can still be controlled normally and suffer no other hindrances. As a result, most players actively seek out the effect for as many characters that can spare the slot.

Tabletop Games

 * You can take this as a character flaw in GURPS, in which case you have to roll to avoid flying into a rage during a fight. Affliction attacks can give temporary disadvantages like this one.

Turn Based Strategy

 * In Fire Emblem, the berserk effect forces characters to attack whoever is closest to them, which usually means their own allies. This is especially problematic late in the game.

Confused
Characters will act unpredictably. They may strike enemies, their companions or even (inexplicably) themselves. Or they may just do nothing and skip a turn. Often, the computer takes complete control of confused characters and selects commands at random, although in some cases the player will still be able to issue commands and the computer will merely select the target at random, and in other games, "Confusion" may actually be just another word for "Charm". There are many instances of this being only usable by female Party members, cast with a Fan Service-laden dance.

First Person Shooter

 * Perfect Dark Zero's Psychosis Gun (in a rare non-RPG example) negates all forms of team-coloration and enables the victim's friendly-fire. When everyone is the same dull gray color, it's surprisingly easy to panic at an approaching teammate...

MMORPGs

 * In Phantasy Star Online, one of the status effects that is probably confused causes the player's character to run in random directions - gunners will fire in about every direction but what you want them to and run into enemies so it's best just to stay very still and wait.
 * Confused enemies will attack whatever is closest.
 * City of Heroes has a player-controlled version of this in the form of Confuse powers. When a player is confused, the player's powers lose friend/foe recognition abilities (so you can attack allies and heal enemies), and upon activating any power, the player's target shifts to a randomly-selected character, friend or foe, and the power is executed on that target. This is dangerous, because the character could potentially work anyway, or it could potentially backfire horribly. On the other hand, standing still and doing nothing is still an option. Because of player abuse, confuse effects from enemies have such short duration that they barely have any effect.
 * While fairly rare in World of Warcraft a fairly notorious confuse effect came from Blackheart the Inciter, who confused the entire party for 15 seconds every minute or so, then just sat back and watched the fun. Apart from using everyone's cooldown abilities the actions taken were pretty random, and one of the more notorious ones was a druid who woke up from their confusion to find they'd teleported themselves to Moonglade. Which is in another dimension. Probably not what the programmers intended.

Roguelike

 * In Nethack, many scrolls will have a different effect if the one reading the scroll is confused.

Role Playing Game

 * Earthbound has two versions of this ailment: the standard confusion (referred to as "feeling strange"), and "Mushroomization" doubles as a Meta-Effect out of battle.
 * Confusion in most games (most notably the Final Fantasy series) isn't really confusion so much as it is a disguised Charm effect: a temporary Face Heel Turn in which your characters will do nothing but attack each other or themselves. However, a few games actually avert that description (namely Final Fantasy Tactics and Final Fantasy X-2), where your characters' actions are truly random. However, this can actually prove to be worse, especially when your Confused character uses that Megalixir you've saved up for so long while your party is at full health/MP....
 * Final Fantasy VI wins the award for "Best Fridge Logic as a Result of a Standard Status Effect, EVER" - Sabin, while zombified (which is similar to muddle, but can't be cured by attacking the victim), can use Bum Rush on himself. Bum Rush is an attack that does damage by running around the target. The attack animation for this is weird.
 * Confusion in Final Fantasy X means that they can attack the enemy, but usually don't; this can lead to much hilarity when Wakka hits himself in the head with a petrifying blitzball and dies instantly.
 * And then you've got the infamous Malboros, who in most games love inflicting this status and Berserk together. On all of your party members. All you can do then is pray that the first character who gets hit can survive the blow (which they rarely do); if not, the combination turns into the status effect equivalent of a Total Party Kill.
 * In Infinite Undiscovery, if the player character gets confused the game inverts your controls and turns off friendly fire immunity but you aren't forced to attack anyone. Other characters will attack whatever is nearest as usual.
 * Pokémon uses this. When confused, a Pokemon has a chance of hurting itself rather than the opponent each time you try to attack. After a few turns the Pokemon can snap out of it, or it can leave battle to do so.
 * Confusion is pretty much the only status ailment in the Pokemon series that can stack with other status effects, and it's also one of only a few that couldn't be cured by some sort of item (at least not in the first generation of games; Full Restores, Full Heals or Max Revives can cure it in subsequent generations). It also seems to have the largest number of moves that can cause it, at least when fighting computers...
 * In the Pokémon Mystery Dungeon games, confusion makes you move and attack in random directions until it wears off. However, you can still throw items in whatever direction you want, including projectile items.
 * In the card game, if a confused Pokémon tries to attack, its owner must flip a coin. If the flip lands on tails, it does 30 damage to itself. Like in the games, switching it out cures it.
 * In Shin Megami Tensei games, confuse has a chance of making the affected character do something... Well, really stupid. A common manifestation is inexplicably tossing macca everywhere or simply hurting themselves a la Pokemon.
 * A confused character in Chrono Trigger will attack whatever is the closest to him, be it friend or foe.
 * Suffering confusion in Radiata Stories will make your player character control awkwardly, and your attacks can damage your allies.
 * Frenzy from Elder Scrolls Oblivion can be used to turn enemies against each other and even their own summoned creatures. Custom spells can have entire towns killing each other.
 * In World of Mana, confusion temporarily reverses your controls.
 * Wild Arms will allow you to choose an option in battle, but not the target.
 * Confusion in the Dragon Quest series isn't just "randomly attack an ally." Confused characters and enemies can wind up doing some pretty funny things, such as trying to run away but failing, trying to attack but not being able to keep up with your body, and sometimes getting paralyzed for no good reason. Ironically the paralysis is actually beneficial to the player, as it prevents the character from attacking his allies!
 * In the Kingdom Hearts series, confusion simply reverses your controls for the duration. In the case of enemies, it makes them attack erratically, and allows them to hurt friend and foe alike.
 * A particularly annoying variant of it is present in Xenoblade Chronicles, where it causes the afflicted characters to run around aimlessly and uncontrollably. They're also completely incapable of doing anything else until it wears off.

Tabletop Games

 * Dungeons and Dragons had the "behave randomly" version of this, as well as the more permanent Insanity. The "attack self" variant was also present in the psionic power Death Urge.
 * Fright Checks in GURPS can sometimes be changed into Awe or Confusion checks, which are mechanically similar, but roll on a different table for their effects. The Terror advantage, appropriately modified, can cause any of them.

Third Person Shooter

 * In Kid Icarus Uprising, confused players will wander uncontrollably in various directions and randomly attack.

Turn Based Strategy

 * Shining Force is a little more merciful with it's confusion: A lot of the time, the confused character just stands there and mumbles to himself.

Charm
Your character gets controlled by the other side and often can attack you with both their basic attacks and as well as their spells and special abilities. If the person taken over can cast healing magic they may even use the magic to cure the members of the enemy party. This can sometimes be one of the harder to cure effects, although sometimes simply attacking the charmed person can break its effect.

Action Adventure

 * Castlevania Portrait of Ruin has one boss do this; if you're playing as Jonathan (or have both characters out at once) she blows a kiss that can charm him into attacking Charlotte. A potential pain since Jonathan has the higher ATK. If Charlotte gets hit by the heart, she just takes a tiny bit of damage and flinches.

MMORPGs

 * Once again, there are several different versions of this in World of Warcraft. The most famous is the Priest spell "Mind Control", which lets you control a hostile enemy or player. In PvE, it's used as a form of crowd control. In Pv P, it's used to make enemy players jump off cliffs. Mind Control is also used by certain enemies, probably most effectively by Yogg-Saron, who casts an unbreakable Mind Control spell on any player whose Sanity Buff hits zero.
 * There are also spells such as "Enslave Demon", which allow players to take an enemy creature as a pet for a short time, similar to the Hunter's Tame Beast skill.
 * And of course the warlock demon pet Succubus has a spell, called Seduce, which will stop an enemy humanoid in their tracks with infatuation (complete with floating hearts) until they are hit or the spell runs out.
 * City of Heroes has charm-like powers in the form of confuse used on NPC characters. The confused enemy will not just attack at random, it will specifically and exclusively target its own allies and ignore the players. If all of its allies are down and players are all that's left, it will idle until killed or until the effect wears off. However, confuse effects will not prevent the enemy from using beneficial powers on its allies at the same time, leading to the bizarre spectacle of a zombie master killing his own zombies, resurrecting them, then killing them again, or a sorcerer alternating between blasting and healing his friends.

Role Playing Game

 * The SaGa series from the Romancing Sa Ga trilogy onward is notorious for this ailment, especially at certain bosses.
 * There is a sort of Charm effect in Pokémon; when a Pokemon is under the effects of the Infatuation status condition, there is a 50% chance that they will be unable to perform their attack (in which case they are "immobilized by love"). This condition is caused by the move Attract and the ability Cute Charm, and only affects Pokemon of the opposite gender (e.g, a female Pokemon who uses Attract on a male Pokemon, or is struck with a physical attack by a male Pokemon; genderless Pokémon and Pokémon with the ability Oblivious are completely immune to the effect).
 * The worst possible effect to suffer in Persona 3 and by extension the Shin Megami Tensei series, especially if one of your healers gets hit. One of the most famous screw-yous in the game is if the final boss of the former hits your healer with Charm, and the healer in turn casts the full-heal Diarahan on it. To put it in perspective, the final boss's last form has 6000 hitpoints. Characters in your party should at this point deal about 150 damage per hit. And the charm-reheal cycle can theoretically go on forever.
 * Other games in the series have physical or potent magical attacks that will additionally slap everyone on your party with this, adding insult to injury.
 * A Charmed character in Black Sigil: Blade of the Exiled will, as per standard, turn on your party. Luckily, they aren't very smart and tend to avoid using their more powerful spells and attacks.
 * Called Enthralled in The Last Remnant (and the visual effect is the union being controlled by the enemy with marionette strings), the victim of this effect will attack your other unions and always kill them, since they do the same damage that you do controlling them. The only saving grace is that you can also kill them quite easily, and revive them in the same turn.
 * A handful of enemies in Final Fantasy VI (Barb-E, a basic enemy and Goddess, one of the last bosses, both of which look like human women) have the incredibly annoying spell Love Token, which causes the affected character to leap in front of any attacks aimed toward that enemy, taking the damage instead. They will even jump in the way of their own attacks if commanded to attack that enemy. Generally, the simplest way to deal with this is to kill the affected character and revive them, and hope that the enemy doesn't use the move again.

Tabletop Games

 * Depending on the skill levels of the players involved, Charms in Dungeons and Dragons are usually less "make them attack their friends" than "make them think you're their best friend in the whole world". They won't attack the charmer (or his allies, if the charmer asks nicely), but neither will they just attack their friends without good cause (though the cause can conceivably be because they're attacking his new best friend in the whole world).
 * On the other hand, the "Dominate" spells have the charmer actually taking over the mind of the victim, thus making these more like the standard Charm status effect from other games.
 * GURPS has Mind Control for the usual, temporary version of this; it comes in degrees, so if you have to decide every last little thing your new puppet does, the advantage is worth fewer points. For vampires, zombies, and the like, the Dominance advantage will infect your enemy and make them your thrall, although to keep them as your thrall, you have to pay Character Points to get them as an Ally.

Turn Based Strategy

 * One of the standout examples from the Final Fantasy series comes from Final Fantasy Tactics a 2. In one mission you're assigned to go take out a group of Cassie Malboros, pink Malboros with ribbons (implied to be the source of THE Ribbons, the ultimate status-effect-nullifying accessory.) The major difficulty of the fight is the fact that the Cassies have an area-effect high-accuracy Charm ability.
 * Final Fantasy Tactics takes this a step further with the "Invite" status, which is a permanent Charm effect. If the Invited enemy survives the battle, it will even join your team.

Frozen
Characters are unable to act. Like sleep, this condition tends to stick around, but if the enemy is dumb enough to use a fire attack on a frozen character, that will often cure the effect. Don't expect it to have any lasting effects.

Fighting Game

 * Characters can be frozen in Super Smash Brothers. Most of the time it's the result of the Freezie item, though the ice climbers can induce it for a split second and it's a possible effect of Game and Watch's Side B. They're encased in a large chunk of ice that can't be knocked back very far, but still allows the character to take damage. Mashing is required to break out, and the more damage a character has, the longer they stay in. Fire based moves break the ice instantly, however.

Hack and Slash

 * In Diablo 2, the Frozen status severely slows down those afflicted. When killed, there's a good chance the target will explode, destroying the corpse.

MMORPGs

 * Being frozen in Ragnarok Online is easily cured- just get hit. The biggest problem is that it changes the character's element to Water for the duration of the effect, increasing damage from Wind based attacks.
 * World of Warcraft has three versions of being frozen; one simply renders you unable to move (but does not prevent other actions), while the second is this trope. In most cases, it immediately wears off upon receiving any damage. Mages deserve special mention for being able to freeze themselves in a block of ice, clearing all debuffs and becoming invulnerable for up to 10 seconds, at the cost of being unable to act. The third type, used primarily by bosses, encases the target in a block of ice that must be destroyed via attacks to free the player. If not broken, the player will stay in there more or less forever (or at least until the encounter ends).
 * Monster Hunter takes this in two forms. Iceblight is a Chill, which causes you to lose Stamina faster (its counterpart, Waterblight, causes you to recover Stamina slower). There's also Snowy, which covers your character in ice, slows you down and keeps you from attacking.
 * Spiral Knights has a bit of a merciful Freeze: You may not move or change direction but can still attack and shield, and recovery is as simple as being hit by anything or thawing naturally. A great crowd control status, though, as frozen monsters are effectively out of the fight, and monsters actually take decent damage if they thaw.

Real Time Strategy

 * In Command and Conquer, any frozen unit/building can be shattered and killed by even the most pitiful attack. In one hit.
 * This is probably more realistic than it seems for sufficiently-frozen things (and it would have to be cold to freeze something that quickly), since the bonding breaks down at low temperatures. If you ever get the chance, dip a piece of something soft like an orange or a rubber hose in a tub of liquid nitrogen and throw it at the wall.
 * In War Craft 3 certain units can freeze buildings, preventing them from producing. Inexplicably, the same attack does not affect normal units.
 * It does slow them down, but presumably they are moving too much to freeze solid.
 * In all 3 Patapon games, Patapons, enemies, and bosses can get frozen and will not move from their place until cured or killed.
 * One boss even starts the battle in a chunk of ice and occasionally freezes everyone on screen (even himself).

Role Playing Game

 * Vexen can freeze Sora in every battle against him in the Kingdom Hearts series. Most ice-based enemies can also freeze you in 358/2 Days... even if you are playing as Vexen.
 * In Final Fantasy IX, being frozen additionally makes you die if you are hit by a melee attack.
 * Certain Fire type attacks allow the frozen Pokémon to free themselves... but freezing moves are unlikely to be used on them in the first place. In fact, Freeze is the least seen standard status effect in the Pokemon games, as it has no dedicated high-accuracy move and is only found as a low-percentage side effect of most Ice moves.
 * An alternate way to defrost a frozen pokemon is to trick your opponent into hitting them with a fire type attack by switching pokemon. Of course, you want to be sure that your pokemon will survive the fire attack before you try this.
 * As of Generation II, there's also about a 10% chance of your Pokemon thawing out by itself on its turn.
 * Paper Mario the Thousand Year Door, you can be frozen by certain enemies. Due to the ice area coming in late in the game, and enemies that use the effect only appearing in certain areas, it isn't that high a priority for players . . . but due to the fact that enemies can still hit you while you're frozen, you take damage when you thaw, AND you can get re-frozen rather easily, this is one of the more perilous status effects in the game (and it doesn't help that the Bonus Boss has the ability to freeze you with one of its breath attacks).
 * Shin Megami Tensei games using the Press Turn system make the Frozen effect a godsend when it affects enemies. Frozen enemies will have their Agility reduced to zero, and all physical attacks will ignore their defense and will always hit critical, which gives you an extra turn. A high-level spell called Cocytus (and its upgraded form, Niflheim) will almost always inflict this status. It's the only feasible method of killing Arahabakis. Of course, the effect is just as devastating when you are affected.
 * World of Mana calls this the "Snowman" ailment; in Legend of Mana, this results in massive damage while frozen.
 * In Final Fantasy VI, frozen characters turn blue and are unable to act, though they'll accept commands if they're frozen on their turn; they'll carry out the command when thawed. Fire breaks this effect and the afflicted is immune to ice.
 * In Phantasy Star Universe, ice technics and bullets can produce this status at random. Characters will be trapped in ice and unable to move for a short period of time, making them easy targets for other attacks.

Third Person Shooter

 * Being Frozen is one of the most dangerous status effects in Kid Icarus Uprising. It wears off quickly, but being unable to move or attack is pretty much a death sentence in multiplayer mode. However, it's still possible to use certain powers, like Effect Recovery or Warp, to try and get out of it. Otherwise you just have to mash buttons and hope you break free.

Turn Based Tactics

 * In Gorky 17 (or: Odium), being frozen renders you unable to act and more vulnerable to damage.

Petrified
Characters are likewise unable to act, and are for all functionally dead; indeed, should the entire party become petrified, expect to see a Game Over. One of the most persistent status effects, generally -- it seldom heals on its own, and sometimes even the Trauma Inn can't cure it -- you need to use a spell or item. Petrified characters are frequently invulnerable to all further damage, but in some cases they may actually suffer increased damage from attacks, or even become Literally Shattered Lives.

Action Adventure

 * In many of the later Castlevania games, being turned to stone freezes you temporarily, but also makes you far more vulnerable to damage -- gods help you if this happens in the Bonus Dungeon.
 * Gorgons can turn you to stone in God of War. Wiggling the joystick will break you out of it (and you have to do it fast before somebody breaks you). But if Kratos is in midair when he's petrified, he shatters on hitting the ground - Game Over. In each game, you acquire a means of petrifying your enemies as well.

MMORPGs

 * Stone Curse in Ragnarok Online has the traditional effect, as well as changing the target's element to Earth, causing double damage from Fire effects.

Real Time Strategy

 * In War Craft 3 this is a beneficial ability which can be used on undead gargoyles. While petrified, the gargoyle is unable to act, but its armor goes way up and it regenerates health rapidly. A similar situation occurs with gargoyles in the World of Warcraft raid instance called Naxxramas Necropolis.

Roguelike

 * In Nethack, being turned to stone is game over, since there's nobody to turn you back. But depending on the source of the effect, it may come on slow enough that you have a chance to save yourself by casting Stone to Flesh, praying or eating something acidic -- the effect seems to be explained by calc build-up.

Role Playing Game

 * There is also at least one instance in Final Fantasy X where a boss can attack a petrified party member, shattering them and leaving you with only two available character slots for the rest of the battle. Being petrified while underwater instantly shatters the victim, on account of the character sinking to the floor and breaking on impact, rather logically.
 * Actually that would be the "Eraser" attack of the Monster Arena boss Shinryu. Not even Death Proof or Stone Proof armor will stop it. (Which is an even bigger pain in the ass) Since you can't swap anyone in for this fight (Since only three of the PCs can hold their breath indefinitely or fight underwater) you can't even let an aeon take the hit. So, if you don't kill him before his first attack (Or he uses one of his other two weaker attacks first) you will be healing one person back to full afterwords.
 * Final Fantasy IV has Gradual Petrify, which makes you take double (and triple and quadruple damage) every time you are hit with it; after three times you become a statue. It's the bread and butter attack of the demon wall.
 * Final Fantasy IX features an evil forest that (along with the monsters inside) turned to stone when you beat the boss at it's heart. For some reason, this also affected a side character caught in the monsters' clutches. While normally, the "soft" item would let you cure the petrified status on anybody; in order to save them, you have to get your hands on a Super-soft.
 * The later games in the Wizardry series feature a particularly nasty Stone effect-it damages vitality the same as dying, and when you do cure a stoned character, it's quite possible they died while stoned, necessitating resurrection and inflicting the vitality loss for dying...
 * In Paper Mario, the stone cap does this. Like the tanuki suit in Super Mario Bros 3, It dramatically increases your defense.
 * In Baldur's Gate, two of the most powerful spells where Stone to Flesh and Flesh to Stone. One specific NPC in the game is trapped in a petrified state. If you use a Stone to Flesh spell on the "Sta tue" she will be extremely grateful and wish to join your party.
 * The Wild Arms series replaces this with Brass, which like in FFIV, is a slow countdown until your character is turned into metal.
 * Earthbound 's version of this is diamondization. The character is functionally death, and you even get a red tinted interface just like when someone has died. (They also look quite comical out of battle, with a head encased in a perfect cut diamond.)
 * In Lufia, petrified characters can still be attacked, but they take zero HP damage until cured.
 * Very frustrating in Shin Megami Tensei, since being Petrified is basically a one-hit kill as all attacks on the Petrified character are instantly treated as Criticals, which, depending on the mechanics of the game, may give them extra turns or the chance to inflict devastating combos. Since The Computer Is a Cheating Bastard, it'll probably only be a matter of time until your main character is hit. Did I mention that depending on the game, Force attacks or a single physical attack will instantly shatter any Petrified victims?
 * Petrification has been somewhat nerfed in most recent games... kind of. You basically become a One Hit Point Wonder, and the character will remain alive (but immobilized) until hit with anything. On the other hand, it's very hard to find an item cure.
 * The Shadow Hearts series also features Petrification. It turns the afficted character into a sitting duck that can be killed in one hit.

Third Person Shooter

 * Petrification is essentially the same as Freezing in Kid Icarus Uprising, except that the petrified target's defense is increased while afflicted, although it does last a little longer. You can try breaking out of it faster by moving the Circle Pad in different directions.

Turn Based Strategy

 * Gorgons will do this in Fire Emblem: The Sacred Stones. The first turn a character has been petrified, any creature that attacks the character has a higher chance of scoring a Critical Hit.
 * Ogre Battle features Cockatrices and Gorgons, whose breath and gaze carry a high chance to petrify. Once petrified, the victim may as well be dead for good, given how rare the curing item is. And if it hits an important character...

Slow
Causes a character to attack and possibly move slower. Shows up more often in games without a turn-based combat system, as the effect is more suited to real-time action. (The turn-based variant usually involves causing the affected character's turn to come up less frequently, or cuts your Action Points in less primitive games). Usually appears in games with a Haste spell, and the two effects will usually cancel each other out.

First Person Shooter

 * Team Fortress 2 has a movement-slowing effect that can be inflicted by at least one weapon. It doesn't last for long, though.

MMORPGs

 * A-gears in Ace Online have this as one of their exclusive skillset. It's possible to snare yourself if you're not careful...
 * Phantasy Star Online had Slow Traps cause this. This was a big problem since the trap appeared out of nowhere for non-androids and those without Trap Visions and it didn't last long enough to warrant a Lv.6 Anti spell.
 * At the beginning City of Heroes did not have a cap to the amount of slow effects that could be stacked upon an enemy (or the player even), meaning that it was possible to keep stacking slow effects until the target was literally paralyzed. It wasn't long before the game was patched to put in a limit preventing this situation from occurring.
 * Mages in World of Warcraft can elect to take this ability. Hunters and their pets are masters of slowing, with Concussive Shot and Frost Trap for the Hunter and several pet families having abilities that slow the target's movement speed. Warriors, Druids and Rogues have Hamstring, a disease, and special poison respectively to slow down opponents.
 * Guild Wars has "crippled" as a condition, in addition to a number of hexes.
 * Ragnarok Online has the skill Decrease Agility. It not only lowers your attack speed and agi stat temporarily, but your character visibly walks slower.
 * Spiral Knights stun causes lowered movement and attack speed. Generally caused by massive hits, and even has a gong sound when inflicted.

Play By Post Games

 * This is the passive ability of Mordred's Noble Phantasm Clarent in Fate Nuovo Guerra. Flynning with it lowers enemy AGI by making their weapon feel heavier with each stroke exchanged.

Real Time Strategy

 * Slows are one of the most common crowd control mechanics in League of Legends. They typically only reduce movement speed, but abilities that also slow the enemy's attack speed are not unheard of.

Role Playing Game

 * In the Final Fantasy series, after IV, it makes the ATP bar fill up a lot, well, slower. In the DS remake of IV, this is absolutely necessary to survive all the bosses, and most of the late game random encounters. On that note, in several games in the series it's one of the only status effects bosses are vulnerable to.
 * There are a few attacks that lower your Pokémon's speed, the most notable of these being String Shot, a move found on most common Bug Pokemon. A more frustrating example (as the bugs are pathetically weak anyway) is the powerful Bubblebeam move, which deals damage and has a chance of lowering your speed. Misty and her Starmie back in the first games loved this move, and the speed-lowering meant that Starmie could quite easily hit you with two Bubblebeams in a row, knocking out most pokemon. Only two types resist the water-type Bubblebeam, and one of them is Water itself. If you didn't pick Bulbasaur, you're in for one hell of a battle.
 * Black Sigil: Blade of the Exiled: A Slowed character's Speed is heavily reduced, making their time bar fill up slower, and thus giving them less actions.
 * "Heavy" status in Ys VI.
 * Present in later games in the Kingdom Hearts series. It turns your enemies into sitting ducks, as it slows down all of their animations, including their flinching from taking damage. Not terribly threatening when it's used against you, as it increases the length of your defensive actions, thus making it easy to wait it out with minimal or no harm.
 * has an enemy called the Gasbag, which leaves a noxious trail behind that damages you while in contact and cuts your speed significantly. You can still attack and block the same, but dodging and walking are slowed.

Stop
Stops a character in time (And I Must Scream style). They are unable to take any action -- much like Paralysis -- but Stop is a much stronger effect and generally cannot be cured in the same manner. In some systems a Stopped character is also considered functionally dead.

MMORPGs

 * Some World of Warcraft enemies use a Time Stop spell, but the in-game effect is identical to being Stunned for the duration.

Role Playing Game

 * Early RPGs treated this as a sort of high-end Paralyze, but later games attribute it to time magic, in which case time stops for the target, but they can still be affected normally.
 * In the Kingdom Hearts series, it has the typical effect of stopping the victim's movements, but all of hits and damage the target takes will only register once the stop effect wears off, which can potentially result in them being immobilized for quite some time even after it wears off.

Tabletop Games

 * Inverted in Dungeons and Dragons, which has a Time Stop spell that instead affects the caster, removing them from the current time stream. This effect only affects the caster, who in turn, can only affect himself with abilities while removed. Spells that run on a timer can also be cast as long as they don't affect anything other than the caster or the area (resulting in a very nasty combo with casting several delayed-blast fireballs on a descending timer, that all go off when Time Stop ends).

Weird Transformation
The character is turned into a weird (sometimes humorous) but universally weak creature. The specific creature tends to vary from game to game -- frogs, pigs, scarecrows, eggplants, rice balls, whatever -- but if this happens to you, you can be sure you're going to have lowered stats (often to the effect of becoming a One Hit Point Wonder) and some inaccessible commands. Sometimes, the attack, spell, or item that causes this effect doubles as a way to cure it (and vice versa).

Board Games

 * In the board game Talisman, you may get turned into a frog temporarily. You lose all your items and companions, and you're very weak while this is in effect.

Hack and Slash

 * In Diablo II you can socket a helm with some runes and wear it, giving you a 1% Chance To Cast Level 50 Delirium When Struck (morph). When this happens, you temporarily transform into a tiny weak demonling carrying a spear.

MMORPGs

 * This is a fairly rare instance of player characters having useful access to such an ability: in World of Warcraft, a mage's ability to "sheep" mobs is a vital aspect of crowd control. However, it does have a downside: the target rapidly restores health and mana, whereas the monster version of this or similiar spells do not (anymore).
 * In more recent patches, Shamans have been given a similar ability; Hex, which turns the target into a frog. The major difference is that Hex does not regenerate health OR break on damage, with the trade off being that it can be cast much less often.
 * In Ragnarok Online you can do this to enemies, using a certain dagger or accessory. But rather than just downgrading the monster, it 'randomly picks one''. This can lead to impressive minibosses inhabiting a low-level area and stomping on new players.
 * Professors/Scholars have a just-for-fun skill called Abracadabra that when used makes the user preform a random skill. You can have Professors doing Assassin skills, it's quite funny. What's even better is that once in a while you'll use a skill called Summon Monster, and if used on another monster it can ocassionally turn it into a Boss monster... complete with drops! To prevent people from spamming Abra it's a costly skill consuming two yellow gems per use.

Platform Game

 * Kid Icarus gives a rare platformer example in the Eggplant Wizards. If Pit gets hit with one of the eggplants they toss, the upper half of his body gets transformed into an eggplant, rendering him unable to use any weapons or items. Oh, and he has to backtrack to the nearest available hospital in order to remove the curse, which may mean dodging MANY monsters if you intend to get there alive.
 * The Eggplant status is back in Uprising, although now it simply wears off after time, and it can be caused by players themselves when using certain powers and items. There's also a newly introduced transformation; being turned into Tempura. It's very similar, but you lose stamina more quickly. And if you're caught by a Tempura Wizard in that state, it will eat you for a One Hit Kill!
 * Every Ratchet and Clank game has one weapon that you can use to turn your enemies into game-specific animals. From Chickens to penguins. Stronger versions of the weapons usually make the transformed foe explode when near other enemies.
 * Magicians in the Ghosts N Goblins series temporarily turn Arthur into a certain creature depending on what armor he is wearing.

Role Playing Game

 * Final Fantasy VI has the Imp status where stats are severely lowered and all special abilities are locked except for the Imp spell. However, there are Imp equipment found in the game that are completely useless on regular characters but godly when equipped on an Imp. There is also the "Zombie" status effect, which overlaps this with "confuse". the character turns green, is counted as "dead" and only attacks hand-to-hand.
 * Many games in the Final Fantasy series feature a Frog or a Mini status which blocks all actions except a very weak physical attack (and sometimes the Frog spell as well). Oddly enough, Final Fantasy IV features the Frog Status, the Mini Status, and the one-time Pig Status. The Pig status effect prevents magic and also cuts attack power, the Mini status effect cuts the target's defense, attack, and evasion to zero while doubling the amount of damage the target takes, and Toad is the same as Mini, but it also prevents the target from using magic that isn't the Toad spell.
 * Final Fantasy III has turning the party small, and into frogs, part of the storyline. Multiple times, in fact. And you still run into random encounters and in one case fight a boss when Mini or frogs -- these encounters are virtually unwinnable unless you've got a magic-heavy party.
 * Final Fantasy IX didn't include this status effect in the battle system, but an important NPC suffers from the classic Toad (in this case a Frog actually) transformation. It's effect on his mind (limiting his intellect) is an important plot point later on. Trying to create an item that will cure him is a rather annoying Fetch Quest with nebulous guidelines.
 * In Secret of Mana, the Lunar element spell, Change Form turned enemies into weaker monsters of the same type, permanently. The utterly whimsical, Lunar Magic, however, afflicted enemies with the "Wimp Out" effect which would greatly weaken them in a similar manner, but only for a limited time.
 * In Super Mario RPG, there is a Guide Dang It item that lets you inflict Sheep status on the enemies, effectively killing them in one hit. Using this item enough changes it to an even better version of the same thing, as it now targets all enemies at once.
 * In normal gameplay, some enemies can turn your characters into scarecrows (disables basic attacks and items) or mushrooms (can't act, but slowly regenerates). Oddly, actual numeric stats aren't lowered in either condition.
 * In the first four .hack// games, this is the player, Kite's, special ability, the Data Drain. Data Drain is typically used on invincible boss monsters to make them vulnerable, but you can use it on regular enemies as well, which will cause them to transform into the lowest level monster that shares their general "form". Since you can only use data drain a limited number of times before getting a game over, this is normally avoided, but it can let you make your way deep into dungeons even if you're too low of a level. And, of course, a monster that's been data drained gives next to no experience, so it will actually prevent you from leveling up normally if you use it too much.
 * Shiren the Wanderer: Mysterious Dungeon 2 features an enemy that at low levels turns your items into rice balls, but at its maximum level turns YOU into a riceball! You're able to move around but do nothing else until it wears off.
 * In Elder Scrolls Oblivion an item called the 'Wabbajack' causes enemies to turn into a random animal for a short time. As this restores their health and can result in less-than-friendly bears and demons being created in place of a possibly weaker enemy, this item is rarely used. On the plus side, it works on an otherwise invincible god-incarnate in the endgame, letting you kill him if you get lucky and end up with something harmless.
 * Pumpkin in Star Ocean: The Last Hope does exactly what it says. Anyone effected can only roll around the battlefield.
 * Heretic and Hexen both have items that launch projectiles that do that - the "Morph Ovum" and the "Porkalator", respectively.
 * In The Legend of Zelda a Link To T He Past, golden star-shaped flashes of light inflict this status effect on Link should he come into contact with said entities. When affected, Link temporarily assumes a bunny form, stripped of his normal abilities.
 * In that game, anyone who enters the Dark World changes into a form based on their inner self. Link has to acquire a certain item to retain his normal form while in the Dark World, but those golden traps somehow nullify the item's effect.
 * In many Castlevania Portrait of Ruin you actually use this intentionally to access small passages. You're still subject to the terrible attack/defense parts though, and no enemies cast it on you.
 * Dalles in Ys II turns Adol into a blue-green monster, and you must go on a long Fetch Quest to return to form. Bammy in Ys IV can also turn Adol into a demon.
 * These occasionally pop up in Shin Megami Tensei games, though they are much rarer than other ailments. Examples are Bael's Bane from Baal Avatar in Shin Megami Tensei Nocturne and Zotzilaha's Bane from Digital Devil Saga.

Fear
Causes a character to run away, perhaps even completely fleeing the battle. Otherwise, the character may be unable to take any actions due to fear, or may suffer lowered attack and defensive scores.

MMORPGs

 * Warlocks in World of Warcraft are well known for this ability, but a few other classes have limited versions; priests have Psychic Scream and warriors Intimidating Shout, both of which will scatter an entire group.
 * City of Heroes has two types of Fear effects, owing to its development history. One type causes NPC enemies (and NPC enemies only) to simply drop what they are doing and run away. This does not work on players, as it is an order to the AI. The second type of Fear affects both NPC and player characters, causing them to tremble with fear and be unable to take any action. Characters trembling in fear, however, can still lash out at attackers, essentially getting one free attack to retaliate with when attacked, though this is only doable every once in a while, rather than full-time.
 * The Lord of the Rings Online has fear and dread. Fear is pretty common; dread is produced only by the top bosses.
 * Fear gives damage over time, since health is morale, or assorted debuffs, depending on the source.
 * Dread reduces effective level, maximum morale and power. At high strength, it forces the player to cower helplessly, while reducing morale to 1% of normal. In the worst cases, the Eye of Sauron fills the screen, blinding the hapless player.

Play By Post Games

 * El Cid's Noble Phantasms in Fate Nuovo Guerra focus on this, particularly the attack/defense-lowering effect. Servants with high Bravery are unaffected.

Real Time Strategy

 * Some champions in League of Legends can inspire Fear in enemies, slowing them and causing them to run around randomly for a short period. Although less reliable than a straight-up stun, it does mean that they can walk closer to danger. Or further away.

Role Playing Game

 * Elder Scrolls Oblivion has two such effects: Turn Undead for less fresh enemies and Demoralize for everybody else.
 * In Pokémon, the move Roar scares the opponent into fleeing the battle (or switching out in trainer battles). The mysterious ghosts in Lavender Tower (pre-Silph Scope), make your pokemon "paralysed with fear" and unable to do anything.
 * Also, several moves have a chance of making the opponent flinch, which makes them skip their turn. Only the faster Pokemon can cause flinching, so one strategy used is "para-flinch": first paralyze the opponent, which will pretty much ensure that you go first. Then, use Flinching attacks. Even if the attack doesn't make the enemy flinch, there is still a 25% chance it will skip its turn due to the paralysis, thus really cutting down the probability the opponent will attack. There also exists one attack, Fake Out, which strikes first and has a 100% chance of making the opponent flinch... but it can only be used on the first turn that Pokemon was sent out. The King's Rock item, when held, automatically adds a chance of flinching to any attack. Finally, some Pokemon have abilities to deal with flinching, either by preventing them (Inner Focus) or by raising Speed when flinched (Steadfast), presumably so they go first and thus cannot flinch from attacks any more.
 * Fear in Super Mario RPG halves the victim's attack and defense, making their attacks weaker and making them take more damage from hits. It's a pain to deal with when it happens to you, but you can inflict fear upon enemies too, primarily with Bowser's Big Boo spell.
 * Persona has two versions: Fear and Distress. Fear will sometimes cause a party member to freeze up, stealing their turn, and sometimes makes them run away outright. Distress weakens them, and any attack that hits them while they're distressed is an automatic Critical Hit. An additional One Hit Kill move, Ghastly Wail, will infallibly execute any enemy and ally inflicted with Fear.
 * Shin Megami Tensei Strange Journey has it as a very rare effect. However, the few enemies that use it are virtually Demonic Spiders.
 * Shin Megami Tensei games also occasionally have Intimidate as a conversation skill.
 * Fear was another status effect used in The Legend of Dragoon. It cuts attack and defense in half, and the afflicted character is shown to have blue skulls floating around them, and visibly shivering.

Tabletop Games

 * Dungeons and Dragons likes this one with basic fear spells and fear auras that surround powerful enemies. Fear also comes in several increments, from "Shaken" which merely reduces your combat effectiveness to "Cowering" which renders you completely helpless.
 * Magic the Gathering has a keyword for Fear: It makes the creature with it unblockable except by artifact creatures (no emotions) and black creatures (who, presumably, would not be afraid of what other things are afraid of.) A newer ability called Intimidate makes a creature unblockable except by artifact creatures (again, no emotions) and creatures that share a color with that creature (why would one be intimidated by something familiar?)

Turn Based Strategy

 * In a double example of Weird Transformation and Fear, in Final Fantasy Tactics reducing a character's brave to minimal levels will transform them into a chicken; they automatically flee every turn and regenerate their brave.

A Meta-Effect
A condition which interferes with the player's control interface somehow, such as by obscuring parts of the screen or, yes, reversing the controls. Hard to justify with the context of the game world, so it often gets folded in with Confusion, curses, or sanity somehow. Most of the "sanity effects" in Eternal Darkness are of this type (such as having the screen blank, the sound mute, or the controlls not work, and even deleting the mem card [thankfully falsely] and putting up a Sequel Hook card).

Action Game

 * The genedisruptor beam in Evolva, which has two effects: on your party members that you're not controlling at the moment, it makes them attack each other, something like Confusion; on the directly controlled partly member, it inverts the controls.

Driving Game

 * Some versions of Mario Kart have an "oil" weapon that splatters a player's screen with dripping black spots, making it extremely hard to see where you're driving.

First Person Shooter

 * In Bio Shock, you can get Jack drunk. Your screen goes into double vision, and you lurch around.
 * Borderlands has the Daze effect for enemies and players. A character who is dazed moves slower and their accuracy drops.
 * Team Fortress Classic gives the Spy Gas Grenades, which cause players who are hit by it to experience severe hallucinations, which include seeing enemies and teammates, among other things. The Medic and Scout get Concussion Grenades, which cause those hit to have their view sway uncontrollably, making it harder to aim.

MMORPGs

 * While usually not a status effect per se, World of Warcraft characters can get drunk, which obscures the players vision of the game and makes movement rather uncontrollable. This is usually done intentionally for fun (ingame holidays often serve free alcohol), but a few instances of it being inflicted by monsters exist as well. Unfortunately, characters sober up from those much faster. It also simulates impaired judgment when your character is "totally smashed", by making anything with a level look up to five levels lower than it actually is. A very subtle side-effect of being drunken is that your depth perception actually is slightly off.
 * Getting your character drunk in The Lord of the Rings Online works mostly the same way, with the addition of your character eventually passing out and waking up somewhere else. A number of ingame holiday quests require that your character are drunk while doing them.
 * Guild Wars has this too: drinking alcohol will give your character the "intoxicated" effect, causing the screen to blur (with the effect becoming more pronounced the more you've had) and make your character randomly emote (/sit, /moan etc) and mutter amusing things ("I love you man!", "I think I'm gonna be sick"). This is mostly just for fun, but a handful of PvE-only skills in the game require that your character be intoxicated to get the full effect from them.

Platformers

 * The infamous "Touch Fuzzy, Get Dizzy" Interface Screw from Yoshis Island.

Roguelike

 * Nethack has the hallucination effect, which causes the symbols representing monsters and items to constantly shift, makes it impossible to distinguish whether a monster is hostile/neutral/friendly, makes the game give humorous alternate message, and in the Slash'EM variant makes the contents of your pack look different every time you examine your inventory. Combat messages from monsters while hallucinating even list things that aren't even part of the game, such as Klingons and Pokémon.
 * In the RTS Star Trek: Armada, the Borg have the nanites ability. When cast on one of your ships, your control panels and minimap run around the screen. Not only does this obscure half of the battle, but hotkeys are disabled too, you have to find and click on your moving command bar to issue orders. Just hope it isn't hiding behind something else!

Role Playing Game

 * In Baten Kaitos, you select the "spirit numbers" on each magnus card to make combos. These numbers typically appear in the corners of each card, and the numbers stay in the same place every time the magnuss card is used. However, the status effects Headache and Confusion change this. Headache causes the numbers to shift to the center of each edge, rather than at the corners, and the numbers are switched up. Confusion makes the numbers to actually spin around the card, which makes getting good combos much more difficult.
 * The Elder Scrolls III: Morrowind has the effect Blind reduce visibility by the power of the effect. 100% Blind literally makes the screen completely black. One rare item called "Boots of Blinding Speed" increases your speed by 200 (the normal max is 100) but makes it impossible to see where you're going. If you cast a magic resistance spell before equipping the boots, you can negate the blind effect while keeping the full speed boost.
 * Confusion in Digimon World 3 changes your battle menu to include actions such as Laugh, Cry, and Seduce. One of the actions will correspond to your basic attack. The others do exactly what they say.
 * You know how every game in the Shadow Hearts franchise (minus Koudelka) utilizes the Judgment Ring in order to determine whether you act in combat and how accurately you do so? You better believe that the Ring itself is subject to status effects.
 * "Tight Ring" narrows down the target areas.
 * "Reverse Ring" reverses the direction that the bar sweeps.
 * "Blind Ring" eliminates the target areas entirely to force you to hit them from memory.
 * "Fast Ring" speeds the sweep up.
 * "Fickle Ring" causes the bar to become sporadic in its speed.
 * "Small Ring" shrinks the Ring itself.
 * "Up Ring" gradually accelerates the bar's sweep.
 * "Fake Ring" throws false target areas at you.
 * "Random Ring" changes the target areas around between appearances.
 * "Confuse" status in the Ys series reverses your controls.

Third Person Shooter

 * You can blind opponents in multiplayer by using a power in Kid Icarus Uprising. It completely blacks out the screen for a few seconds. There's also the Spinning and Shaking status effects. Spinning causes the camera to wildly spin around at high speeds to disorient you. Shaking causes the targeting reticule to erratically move around uncontrollably, ruining your accuracy.

Instant Death
a.k.a. One Hit Kill. One cast, one death, no waiting. Obviously this is a ridiculously powerful ability, and it's often reserved for bosses -- games where common enemies can use this with regularity tend to be frustrating, since there's often nothing you can do to stop it except pray to the Random Number God that it misses. Your party members will rarely have any resistance to this effect whatsoever, whereas enemies are frequently born with resistance to it and bosses have contractual immunity to it, making it a Useless Useful Spell in most systems.

MMORPGs

 * World of Warcraft likes to give bosses One Hit Kill abilities, but special mention goes to Archimonde. Anyone who has had to learn this encounter will be very familiar with his Finger of Death ability, which he uses to mop up the raid when things go pear-shaped. Under certain conditions he uses Hand of Death instead, which does five times the damage (five fingers, geddit?). To everyone at once. Ouch.
 * The description for the Finger of Death move strays into Large Ham territory. Inflicts 20,000 Shadow damage to you, your children, and your children's children!
 * Let's not forget Yogg-Saron's berserk ability, which is really straightforward. Extinguishes all life. Kaput.
 * City of Heroes has what's known as the "one-shot code," which basically prevents a player character from being taken down to no Hit Points if he started from full Hit Points. However, a character starting out damage can very much be taken out in one hit, and attacks that deal multiple "ticks" of damage will get around this safeguard anyway. That said, some very powerful bosses can and will use large-scale, incredibly devastating attacks that have the potential to kill every player in the vicinity, often using circumstances to sidestep safeguards.
 * Phantasy Star Online's Megid. It casts a dark ball that (sometimes) instantly kills an enemy. A Useless Useful Spell when used by a player... But when used by an enemy you can expect it to work 99% of the time. Specifically, Ob Lilies in Ultimate Caves just LOVE this spell. It does have an Achilles Heel however, it's chance to work is modified by your EDK stat. Too bad most armors don't have much more than 20, and you 'could' sacrifice slots for EDK units, but you just lose too much.
 * It also subverts the Useless Useful Spell a little if a Force has it at level 30. (Which is a 100% chance to work... modified by Enemy EDK.) There are quite a few enemies that you could use it on with great effect, but most enemies have an extremely high EDK stat, making it useless agenst other enemies.
 * The special attack for weapons, 'Hell' does the same thing, but with one diffrence. A unit called V502 doubles the chance of it working. If you have a high ammount of accuracy and a V502 unit, you can use the Hell special on just about any non-boss enemy.
 * Guild Wars gives this mechanic to a handful of environmental hazards in the game, most notably the entire ground in the Desolation. (Crossing the Desolation requires taming a giant Sand Worm and riding around in its mouth.) It's also used for fun in outposts -- the only persistent areas in the game, where players can't attack or use skills -- during certain holiday events. Because of this, instant deaths don't count as "real" deaths; your character won't get any death penalty and the death won't get added to your death count.
 * Ragnarok Online has the Coma status, whick doesn't kill you outright but reduces your HP to 1, meaning that the slightest poke will kill you.

Role Playing Game

 * A variant known in Final Fantasy games in the level-based Death spell, which kills any enemy whose level is multiple of 5 and always hits those enemies at 100% accuracy.
 * Final Fantasy I had Poison, a Black Magic spell that killed any enemy instantly but often missed, and Reaper, a spell only usable by bosses that instantly killed one of your party members.
 * Final Fantasy VI had two such spells, Doom and X-Zone. Bosses were usually immune to these spells. However, players could use the Vanish spell on most bosses to give them the usually-beneficial Clear status, which makes a character resistant to all physical attacks but extremely susceptible to magic. So susceptible, in fact, that a bug in the game caused these invisible bosses to lose their immunity to the two instant-death spells! This could be used to trivialize a lot of difficult boss fights.
 * It should be noted that using X-Zone in this manner to kill the randomly-appearing boss Doom Gaze would result in not getting the Bahamut Esper upon his defeat. Not a good call; use Doom instead.
 * Such moves in the Pokémon universe only work if the target's level is lower than or equal to the user's, except in the first game(s) where it was Speed. The moves also have 30% accuracy.
 * When paired with Lock On or Mind Reader these moves have 100% accuracy, however most opponents are smart enough to swap when these moves are used, and few mons eve learn targeting and OHKO moves on a natural legal moveset.
 * Even without such a move or ability, each level difference between the two Pokemon increases the success rate by 1%. Hence, a level 71-100 Pokemon could use 100% instant-kills (however, unless the opponent is a master of EV points and has an Event-Only Legendary, you're unlikely to need them).
 * Shin Megami Tensei games enjoy providing even lowly Mooks with instant-death spells like the Hama and Mudo categories. More infuriating when they happen to miss everyone in the party but the Main Character.
 * Hama and Mudo are the kindest versions of instant death in SMT - typically classed as elemental spells, they can be resisted, blocked, or even repelled. There are also at least two non-elemental, non-blockable instant death spells that Mooks get access to, which always work against characters affected by status effects: Eternal Rest kills sleeping characters, and Ghastly Wail targets the fearful. Some high-end bosses also receive special, similarly unblockable instant kill moves of their own that work off a specific criteria (For instance, ).
 * Shin Megami Tensei Strange Journey. The Law and Neutral Final Boss. Guaranteed instant kill AND saps the victim's HP. AND it can target you. Tee hee!
 * However, SMT makes the skills also useful against a good many enemy monsters, with only a handful being really immune or even repelling them. In addition to that, there are actually bosses who can fall by using these spells on them (though those are rare).
 * Earthbound has the Psi Flash ability. Once it reaches Beta, Gamma or Omega level, it possesses the ability to instantly kill select characters. Only Ness and the boss of the final sanctuary can use it though.
 * And Giygas, who uses it liberally. Night/Sea/Star Pendant required.
 * It's more than just that. The regular enemies Conducting Menace, Conducting Spirit, and Wild n' Wooly Shambler and the bosses Evil Mani-Mani, Thunder and Storm, Kraken, Diamond Dog, Ness's Nightmare and Giygas can use at least Flash Beta or its non-PSI (read: non-blockable) equivalent, Glorious Light/Summoned a Storm. And absent protective pendants, all of the Player Characters are * very* vulnerable to Flash and will frequently be paralyzed or KO'd by even the Beta level.
 * Also, there's diamondization, which is basically instant death as well.
 * Dragon Quest games have the spells Whack and Thwack, formerly Beat and Defeat, that can cause death to individuals or a group. Like most of the game's status-causing spells, these have a better chance of working in general than their equivalents in other RPGs, but Whack and Thwack cost a lot of MP, and they're still not extremely reliable. Dragon Quest IX adds Kathwack, which can kill all enemies, even if they are in multiple groups - but it's unreliable as ever!
 * Some enemies in the Golden Sun franchise have attacks that either do 1 point of damage or 1 hit KO.
 * The Shadow Hearts series have the Instant Death ring ability. It's insteresting to note how the games make a point to mention that it's just another round-of-the-mill status ailment that can be easily negated by equiping your character with the correct acccesory - in this case, a sad looking Teddie bear whose origins varies from game to game
 * Present rather uncommonly in Xenoblade Chronicles, and only towards the end. Perhaps the most notable example is a superboss that causes instant death if you so much as hit it without protection.

Real Time Strategy

 * Some bosses in Patapon have an attack that will decimate your ENTIRE army (Even Hatapon) unless you dodge.
 * Even further: Some bosses have attacks you can't dodge, meaning you have to defend and hope for the best.
 * Some bosses have attacks that destroy your Patapon, caps and all (meaning they can't be revived.
 * Sacrifice has the Death spell which summons a shadowy figure that instantly kills every unit it can reach. However its double edge as it will attack the summoners own units as well.

Third Person Shooter

 * You can add Instant Death to your attacks using a power in Kid Icarus Uprising, but only in single-player mode.

Destroyed
The character's body is reduced to ashes or otherwise destroyed. It may not always be Deader Than Dead, depending on the game, however it differs from the standard KO in that it is much more difficult to revive them.

Role Playing Game

 * Might and Magic has Eradicated, which happens if a character takes way too much damage.
 * Exile/Avernum has Dust, the cause is the same as in Might and Magic.
 * Characters in Ultima III could be turned to ash. Thankfully, the most powerful cleric spell could reverse this.
 * In Final Fantasy X and Final Fantasy X 2 getting hit while Petrified sometimes results in your character shattering, with no way to revive them until after the fight.
 * It would also happen if you got petrified underwater.
 * In the Wizardry games, a failed resurrection could result in being turned to "ashes", only curable by an even stronger resurrection -- and that, too, could fail, causing the victim to be "gone".
 * In Final Fantasy VIII, Ultimecia has the effect of "Absorbing into time", which is cast on any dead player character, dissolves them and prevents them from being revived.
 * The Pokémon variant of this is Self-Destruct or Explosion, though no one actually dies per se. Both OHKO the user, while severely damaging or OHKO-ing the opponent as well. Ghost Pokemon are immune to this. The most common user of both moves is the Geodude/Graveler/Golem line, but Voltorb/Electrode is well known for it as well.

Tabletop Games

 * In Dungeons and Dragons some spells (such as Disintegrate) could cause this. Characters destroyed in this manner cannot be revived with Raise Dead, requiring the more powerful Resurrection or even True Resurrection.
 * Not that its possible to recover from normal death in Paranoia, but if you roll a "Vaporised" result on the damage table... guess what happens to you.

Doom
Similar to Instant Death, but activates after a set amount of time or turns instead of instantaneously; usually accompanied by some sort of indicaiton of the time left. It can sometimes be cured before this by standard status-removing magic; otherwise by ending the battle before the counter reaches zero.

General

 * Some poorly programmed games will even continue the countdown through victory animations, possibly wiping out the final party member mid-boogie.

MMORPGs

 * In Mount Hyjal, a raid dungeon in World of Warcraft's Burning Crusade expansion, one of the bosses casts a debuff called Doom, which kills the target player upon fading and spawns a demon from their corpse.
 * More familiar is the Warlock's "Curse of Doom" spell. It does nothing for 60 seconds, but when it expires, it inflicts a very high amount of damage on the target. If the damage from the curse is what strikes the killing blow, a Doomguard will be summoned from the corpse. (However, since he isn't under the Warlock's control, he either needs to be shackled, or the curse can be worse than the cure...)

Roguelike

 * Nethack has a "sick" (food poisoning) condition which is fatal if not cured within a few turns, and a delayed-effect petrification status caused by  which can be cured by.

Role Playing Game

 * In Earthbound, when your characters have a sufficient level, any physical damage that should kill you becomes a Doom effect instead, allowing you to win the battle before you should die (doesn't stop death-inducing Flash attacks, however). Furthermore, while using Lifeup or food on a dying character doesn't seem realistic in stopping death by mortal damage (that's to assume there is anything resembling realism in this game), it's just as effective, and more readily viable in some cases, to throw a Lifeup Gamma than to let them time out and have to toss a more-expensive Healing Gamma/Omega.
 * The Perish Song attack in Pokémon works this way, combined with Mean Look it makes a good strategy against stallers. However, using it when both players are down to their last Pokemon in tournament play is illegal.
 * Also as mentioned above, Brass in the Wild Arms series.
 * Some Psynergy in the Golden Sun franchise puts an eight-turn counter on a certain character, after which they die. This is denoted by four flames next to their head which gradually go out. If a character is hit with this, the game's battle text exclaims that "The Spirit of Death embraces _____"!
 * In Final Fantasy XIII, Eidolons cast this spell on your party leader the instant you start to fight them, essentially making their battles Timed Missions. A lot of bosses will also do this if your party takes too long to kill them. It's also the only status effect in the game that is totally unavoidable.

Turn Based Strategy

 * In Final Fantasy Tactics, an additional Doom counter comes into being after a character dies. If that counter reaches 0, the character is Lost Forever (unless it's an undead, in which case it might revive instead.) If this happens to Ramza, Game Over.

Web Comics

 * One Adventurers strip had Drecker hit with Doom, and complaining that he only got one second for each stage of grief. Another character points out he spent six seconds whining.

Critical
A character in Critical condition is low on hitpoints and near-death. Highly variable between games, it can unlock desperation moves (as in Final Fantasy VI or some of the Tales games) or simply cause effects like a hunched-over posture, a red-tinged screen, or an alert bell. Seeing this as a negative thing to varying degrees is a something of an aversion of Critical Existence Failure. Attacks that specifically cause Critical status instead of inflicting normal damage -- e.g. HP to One -- are rare and often reserved for bosses.

General

 * Videogame bosses are practically guaranteed to become stronger when low on health.

MMORPGs

 * While it is not classified formally as a status effect, reaching a given percentage of health has a myriad of positive and negative effects in World of Warcraft.
 * Several classes have "Execute" abilities (including the warrior ability Execute and the hunter ability Kill Shot) which can only be used when the target is below 20% (sometimes 25%) health. Even more classes have talents that cause their normal abilites to be more powerful against low-health enemies.
 * Many classes also gain benefits when their own health is reduced far enough; Rogues that have trained Cheat Death gain a powerful damage reduction ability instead of hitting zero health, although it only lasts a few seconds and can only activate every minute. Some casters automatically activate shields or self-heals at 50% health.
 * Properly-specced Priests even get healing bonuses on friendly targets at less than half health.
 * Many NPCs (including most bosses) and even certain player characters also get damage increases when their own health reaches a certain level, usually in the form of an "Enrage" effect. This makes the last phase of a fight particularly dangerous.
 * Guild Wars 2 has the "downed" state: when your HP reaches 0, your character will fall to the ground and their skill bar will be replaced by a handful of "downed" skills. If you manage to kill something using these skills before your consciousness meter runs out, you will "rally" and return to form. Otherwise, you will die. If this happens underwater, you will go into a "drowning" state instead, which works in much the same way, except that you can also swim to the surface to rally.

Role Playing Game

 * Starting from the third generation, certain abilities (Overgrow, Blaze, Torrent, and Swarm) can have a bonus to attacks of a Pokémon's type when their HP is below 1/3 of their maximum.
 * Certain berries only activate when the Pokemon is 'in a pinch' (1/3 health or lower) as well. Couple that with certain attacks that do incredible amounts of damage when your pokemon is near death (Reversal, Flail), and letting yourself get beat up by the opponent only to turn the tables seconds later becomes a viable option.
 * F.E.A.R.: Focus Sash + Endeavor + Quick Attack + Rattata. The Focus Sash ensures that, if the user has full HP, the Mon holding it survives any attack with 1 HP. Endeavor sets the enemy's HP equal to the user's. Quick Attack always goes first and will take down that last 1 HP with mandatory Scratch Damage. Fortunately, It Only Works Once, and can be easily countered if the opponent uses their own high-priority attack.
 * Taken to new extremes with the advent of the 5th generation of games, where Sturdy, which used to only provide an immunity to the already-banned OHKO moves, now acts as a built-in Focus Sash that never goes away. Combine this with the normally Useless Useful Item Shell Bell, which restores approximately 1 HP for every 8 damage you do, and you have an invincible plank in Aron.
 * To specify: Level 1 Aron + Endeavor (matches foe's HP to own) + Sturdy + Shell Bell + Sandstorm leads to: opponent attacks Aron, Sturdy leaves Aron at 1 HP, Aron uses Endeavor, lowering the opponent's HP to One, Shell Bell fully restores, Aron's HP, enemy dies from Sandstorm (to which Aron is immune). Rinse and repeat.
 * Some games have equipment that activate or increase in power when the wearer is in critical condition, such as "SOS" items in Square-Enix games.
 * Final Fantasy VI had "Desperation Attacks" - when a character who was in Critical condition launched a standard physical attack, there was a chance of them using an extremely powerful move that would often turn the tide of battle. Each character had his or her own unique Desperation Attack.
 * Lost Kingdoms doesn't really bother with this, unless you're the main character. Where you are, your movement becomes hindered the less hp you have, which makes you easy prey.
 * Shin Megami Tensei Nocturne has Hito-Shura take on a rather fetching red glow and stagger around holding his stomach when on the field.
 * As a rule, Shin Megami Tensei games' bosses using Nocturne's battle system all have a move designed to fracture their one turn into two or four half-turns. Mot in Nocturne is especially hated for his unique ability to abuse this.
 * Paper Mario is a good example of how this can be a beneficial effect, as many badges provided great benefits to Mario when he was at 5 or less (or even only 1) HP. Being probably the most ubiquitous example, Mega Rush increased your attack power by FOUR TIMES if you had a single hit point remaining. This, coupled with an infinitely-comboable Powerbounce attack (and good timing) led to monumental amounts of damage being dealt. This could take out just about every boss that didn't start out invulnerable until a certain event happened (which happened far too often for this to be TOO abusable) before it even had the chance to attack, making it a staple tactic of speedrunners.
 * Thus spawning the Danger Mario technique. Basically, there's an NPC in the game that can lower one stat (either HP, Flower Points, or Badge Points and boost another. Mario has a base 10 HP, and using the NPC will make it 5, putting him in Danger status. Stacking lots of Power Rushes (the aforementioned badge that increases Attack) creates an incredibly dangerous attacker, especially when using Powerbounce.
 * In Final Fantasy VIII, being in critical condition is the most common way to trigger a Limit Break. Since the only other method is by use of a spell that isn't very easy to get and doesn't last very long, this makes it oddly desirable to keep at least part of the active party terminally at critically low HP in order to turn out Limit Breaks at will.
 * If a party member other than the main character is knocked into Critical in Persona 3, they may ask you to let them leave the fight. This can get annoying if they have healing magic, because if you tell them to stay, they'll tell you off... then heal themselves. You suffer no penalties for ordering them to keep fighting, incidentally.
 * The Tales series have always approached this effect somewhat differently with systems like Overlimit and Spirits Blaster. At first, this just provided temporary immunity to staggering when the target took enough damage (essentially, it was something of a desperation move). However, as the games went on, Overlimit gained a gauge that could be built up through causing and receiving damage. Characters were still immune to staggering after it was activated, except the overpowered Mystic Artes were now easier to use since you could trigger them on a whim.
 * Tales of Vesperia takes this one step further with the option to stack up to four Overlimits at once. The PS 3 version increased this to eight.
 * In Sands of Destruction, when a character gets to critical, they get a unique "critical" pose. Morte uses her double-bladed sword to support herself, for instance, and Kire slouches. Taupy gets two, in one, he becomes unsteady on his feet, in another, he pulls a crutch out of Hammerspace.

Survival Horror

 * Characters in the most of the Resident Evil and Dino Crisis series clutch themselves and walk with a limp when low on health. Some of the games also have bleeding out, as mentioned above.

Third Person Shooter

 * There are actually two Critical condition levels in Kid Icarus Uprising. The "In-Peril" condition refers to when your life bar is low enough that it starts flashing. But in single-player mode you can also take enough damage that your life bar shatters completely and you enter "Crisis Mode", where you're basically one hit away from death. However, if you manage to hold out in Crisis Mode, you will eventually recover a small portion of your health. You can customize weapons so that they grant attack boosts or automatic dodging bonuses when you are In-Peril, and the Trade-Off power can be used to purposefully sacrifice all but a sliver of health in exchange for temporary invincibility and massive movement and strength increases.

Cursed
Cause the forces of darkness/light to send upon you a series of horrible magical hexes that will screw you up basically. Ranging from reversed movement to severe attack and defense debuffing. You can still fight but will do so at suboptimal levels, some may even prevent you from healing yourself until a healer comes in and gets rid of it.

Action Adventure

 * Curse works differently in the Castlevania games:
 * Rondo of Blood and Harmony of Dissonance: Slows down character's movement.
 * Symphony of the Night: Character is unable to attack or defend.
 * Aria of Sorrow, Dawn of Sorrow, Portrait of Ruin, and Order of Ecclesia: MP level drops FAST.
 * Lament of Innocence: Character is unable to perform combos.
 * In Castlevania64, being bitten by a vampire renders the character unable to attack or recover health, and they eventually turn into a vampire themselves unless you find a Purifying Crystal.
 * In certain Zelda games, being touched by a Bubble disables your sword, either temporarily, or permanently until you use a potion, touch a Blue Bubble or visit a fairy. In Skyward Sword, cursed enemies disable all items for a period of time. In a game where enemies fight smartly and Link's shield is more vital than ever, this is the last thing you want -- get a Sacred Shield ASAP!

MMORPGs

 * One particularly potent one is from Guild Wars: Spectral Agony. 80% slowed movement and attack speed, and 100hp loss/second (base max hp is ~500).
 * On a less severe note, a major type of debuff in the game is the "hex". Most spellcasting classes can apply hexes, but Necromancers and Mesmers in particular excel at them. Necros even have a skill line called "Curses", while mesmers can dip into "Domination" or "Illusion Magic".
 * In World of Warcraft, the Warlock class is a master of Curses:
 * Curse of Agony, which deals increasing damage as time passes.
 * Curse of the Elements, which both reduces the target's magic resistances and increases the damage they take from magic attacks.
 * Curse of Tongues, which slows casting speed.
 * Curse of Weakness, which reduces the target's armor and physical attack power.
 * Curse of Exhaustion, which lowers the target's movement speed.
 * Curse of Doom, which deal a large amount of damage after a certain amount of time passes.
 * In Final Fantasy XI, Curse reduces max HP and movement speed and usually lasts a maddeningly long time if not cured with Cursna or holy water.
 * Spiral Knights has a rare but powerful curse effect: A cursed player has certain weapons and items marked by the curse, and attempting to use them causes damage. At endgame, this can easily be the entire inventory of the player. At the status lasts 30 seconds (compared to the 7 seconds of everything else). For the enemies, it just damages them every time they do something. The only non-vial method of inflicting the status is the (Gran) Faust. Both yours and that Phantom's.

Role Playing Game

 * Another nasty one is Disease from the later Wizardry games, which while technically a Plague, operates like a curse, and will steadily destroy a character from their skills to permanent stat damage, from which there is no recovery-not even death and resurrection will restore the character.
 * Similarly, Disease from the Wild Arms games will prevent the character from healing while it's in effect.
 * In Final Fantasy VIII & X, a Cursed character is unable to perform Limit Breaks or Overdrives.
 * It didn't help in Final Fantasy X that the aeons were immune to all status effects BUT curse. Of course, those select bosses have status effect causing attack with a myriad of effects. If one's really unlucky, one of the characters will be Cursed. If an aeon gets hit by said attack, they always get cursed.
 * In Treasure of the Rudras, Curse is called Pollution: character cannot cast Mantras until Purifier is used or a Costly MP Mantra is cast that can Purify it
 * And then there's the famous "Mushroom" status from Earthbound, which is essentially this.
 * An odd case in Pokémon. The move Curse works differently depending on the type of the pokemon using it. Ghost type Pokémon remove 50% of their own HP to inflict a poison-like status on the enemy that cuts 1/4 of their HP every turn. Any other type will lower their speed to raise defense and attack.
 * Super Mario RPG's version of the Fear status would fall under this category, as it halves the target's attack and defense stats. Players probably recall the animated cake that has an attack to inflict Fear on the whole party at once.
 * Individual characters can become cursed in Golden Sun, but by two totally different ways. The first way is for a spirit to become bonded with some character, which normally doesn't do much except cause Scratch Damage every odd turn. The second way is to equip something that is cursed (the game will always tell you what equipment is cursed, and the equipment usually has foreboding names, like Devil's Plate and whatnot). Cursed equipment normally has resoundingly high bonuses, but in exchange you cannot remove the equipment, and your character will occasionally be unable to move during battle. Both curses cannot be removed by any item or spell, and you must visit a healer to fix yourself.
 * There is, however, an item called "Cleric's Ring" that one can equip to nullify a curse's effect. Using a cursed weapon while wearing said item can make for a very powerful character, but the weapon cannot be unequipped without visiting a healer.
 * Shin Megami Tensei Nocturne has the Magatama-imparted curses - they weaken you, make you randomly attack allies, and is generally a horrible nuisance. However, being affected by a curse changes the rules in Demon Fusion, making it more likely to inherit better skills and stats - as long as the result of the Fusion is a demon of the darker races, such as Fiends, Fouls, or Fallens.
 * Digital Devil Saga uses another form of Curse, which inflicts upon you the same amount of Physical damage you deal to enemies.
 * Black Sigil: Blade of the Exiled: It's not displayed in battle, but two of your characters spend a good portion of the game Cursed. The effect being that you tend to start battles with anywhere from one to four random status effects and debuffs. Can be a bit annoying when you catch fire as soon as you see a monster.
 * Dragon Quest uses Curse to cause a Stun effect. In Dragon Quest VIII, one bit of foreshadowing is that Curse doesn't work on the main character - while its failure on most characters is "(Character) dodged out of the way", for the main character it's always "But the curse dissipates before it reaches (Hero)!"
 * In Final Fantasy XIII, Curse made you less likely to interrupt enemy actions and more prone to getting your own actions interrupted by the enemy. Its beneficial counterpart, Vigilance, did the exact opposite (they cancel each other out when cast on the same target).
 * In Xenosaga, a cursed character will receive mirror damage. It's particularly unnerving if you don't have anything to get rid of the curse.
 * In Chrono Cross, a cursed character takes stamina damage along with regular damage.
 * In Dark Souls, Basilisks can inflict a 'cursed' status upon you if you stay in their steam for too long. Not only does it instantly turn you to stone and kill you, it also permanently halves your health bar until you use a Purging Stone or go to the healer in New Londo, which requires trekking through a dangerous ruin filled with ghosts. Before patch 1.05, the halving effect even stacked, meaning you could end up with a tiny sliver of a health bar if you were cursed multiple times.

Third Person Shooter

 * The Weakening status effect in Kid Icarus Uprising is much like a cursed effect (notably, the only weapon that has a built-in Weakening status is the Great Reaper Palm). When afflicted, your life bar is halved for short time.

Other
Many games of course may come up with unique status effects of their own. Or just ones that aren't always used.

MMORPGs

 * Final Fantasy XI features "Weight", which lowers evasion and movement speed.
 * Also, "Muddle" prevents you from using items, under "Zombie" you cannot be cured, "Encumberance" removes all your gear and prevents you from re-equipping for a time, and "Amnesia" prevents you from using job abilities and weapon-skills.
 * City of Heroes has a few odd ones:
 * Debuffs that reduce the speed at which the target regains health or stamina.
 * Debuffs that actually reduces the total health or stamina that the target can have.
 * Debuffs that make it so that the target cannot actually be healed at all.
 * Monster Hunter has a few other afflictions - Muddy is the desert counterpart to Snowy, Thunderblight makes you easier to stun, and Dragonblight reduces your Affinity, which in turn impairs the damage you can inflict.
 * Maple Story has seduce, which makes characters forced to move in a certain way, for example, jumping to the left. It also has a debuff called zombify, which makes characters take damage from the priest's heal and reduces the amount potions heal by one half.
 * Guild Wars has Deep Wound, which reduces maximum HP and healing by 20% for its duration. This condition is popular amongst PvPers who like to use a tactic known as "spiking": the entire team targets a single enemy player, counts down from 3, then simultaneously blast them with their most powerful skills.
 * Corpses, of all things, get their own status effect: "Exploited". Once a corpse is exploited, it will turn black and cannot be exploited again, nor can it be unexploited (except through resurrecting and then dying again). This differs from the "Destroyed" effect mentioned above in that it doesn't affect the corpse's ability to get resurrected; instead, it's used to limit certain Necromancer skills which use corpses as a resource.

Real Time Strategy

 * Company of Heroes uses two sets of status effects, one for infantry and one for vehicles. High concentrations of fire, like from a MG42 or Browning .30cal, can suppress and eventually pin enemy infantry, slowing their movement to a crawl and reducing their firepower drastically. Vehicles can suffer critical hits to various components, like engine or main gun Damaged or Destroyed, in addition to being buttoned up by Bren gun fire. The ones that both infantry and vehicles both suffer from are stun and burn damage (no text color to indicate this, but then again it's rather hard to not notice the flames).
 * Dawn of War 2 (which runs on the same engine) uses a similar but simplified system the resembles it's Tabletop Strategy counterpart. Infantry under fire from heavy weapons or special attacks can be suppressed (glowing red unit tag), cutting movement and attack. Vehicles can be disabled (can't do anything for a few seconds), suffer rear armor hits (increased damage, or any damage at all from small arms fire) or go out of control (roll forward swerving wildly and damaging anything it runs over until it hits a wall and explodes), all shown by brief text tags.

Role Playing Game

 * "Thirsty" in Dark Cloud 2 prevented the player from healing until it was taken care of.
 * Shin Megami Tensei Strange Journey has Bomb. If a character suffering from Bomb is hit again, they die instantly, and their HP is divided up and dealt as damage to the rest of the party.
 * Final Fantasy IX has several, including Heat (a particularly brief ailment that kills the afflicted character if they take any action whatsoever), and Trouble (which, if the afflicted character is attacked, hurts the rest of the party for roughly half the damage taken).
 * Final Fantasy XII has Disease, which, rather than damage taking from your current HP, it takes from your maximum HP as you receive damage. Granted, your full HP cap is returned upon clearing the status, it's still a malady you don't want to dilly-dally about clearing up.
 * Note that there are several enemies who inflict Sap and Disease at the same time which, as you can immagine, is quite nasty. Oh, and Disease is the ONLY status in the game that doesn't go away if a character is KO'd and then revived, meaning that if a Diseased character is KO'd, a Phoenix Down would revive them... as a One Hit Point Wonder.
 * Sonny has some ridiculous status effects, which are too many to list. Being knifed in the face is one such example. Really, some get ridiculously odd, it is odd-ish that zombies, insurgents, renegade combat medics, and blade dancing female zombies have to obey the orders of the Mayor of Hew to sit down, and why the heck (even with magic) several things that should have little or no relevance to combat make appearances.
 * Earthbound gave Ness a personal status effect in the form of "homesickness"; if he hadn't contacted his mother in a while, he risked a chance of failing to act in combat thanks to being homesick. Calling home was the usual cure, but hatching a baby chick could provide a brief bit of relief from it if no phones were nearby.
 * In Final Fantasy X 2, the only action an "itchy" character could perform would be to change clothes, which would cure the condition. Fortunately, this could be done relatively quickly, even in combat, and was actually one of the core game mechanics.
 * Xenoblade has a whole slew of different status ailments, with the caveat that the duration is measured in seconds, though combat is fast-paced enough that those few seconds spent helpless can hurt. It also has examples of some statuses requiring prerequisite status effects - for instance, the 'Break' status does bupkis but make the target vulnerable to attacks that cause 'Topple' (target is knocked on their backside, can't move or act and loses special shielding) and a target must be toppled before Daze can be applied (same as topple, but extends the duration and prevents the victim from accumulating aggro, allowing squishier party members to pour on the hurt.)
 * Kingdom Hearts 358/2 Days features several status ailments that are a bit out of here, like Shoe-Glue (prevents your character from jumping), Air Toss (You character gets tossed into the air without being able to recover or attack and take twice the damage), Null-Defense (Enemies deal damage regarless of your character's defense) and Jolt (your character losses 10% of their HP when coming into contact to either allies, enemies and even walls and environment objects) to name a few.
 * Chrono Cross had Fatigue, which had a massive impact on stamina; regeneration is slowed and attacks take more stamina. Thankfully, it's very rarely seen; it's probably the most dangerous status ailment if you don't have a Purify or WhiteOut element allocated.
 * Final Fantasy XIII-2 has Wound damage, which reduces your character's max hp. It goes away after battle, and can be healed by a Wound Potion. Not dealing with wound damage can be pretty dangerous in some of the harder battles.
 * Final Fantasy Crystal Chronicles Ring of Fates and Final Fantasy Crystal Chronicles Echoes of Time Has Gravity, which prevents you from jumping.

Turn Based Strategy

 * Nippon Ichi games such as Disgaea have the "Deprave" status effect, signified by a black swirl over the victim's head. Depraved characters earn no experience, which of course is far more effective against the player than it is the enemy. Worse, it's also said that a depraved character doesn't give experience either, meaning you don't want to inflict it at all.
 * From Disgaea 2 onward, Deprave also chops off 20% of the afflicted character's stats.
 * Also in some Nippon Ichi games is an effect they call "Critical", but is unlike the Critical above (though some units do have low HP effects). This Critical is an effect on Geo Panels in Disgaea and a room in Soul Nomad. If you're standing on a Critical Geo Panel, any attack that hits (doesn't miss) kills you. Phantom Brave had a proto-critical effect in the "Gamble" status condition, which made the odds 50/50 of missing or killing the Gambled character.