Self-Imposed Challenge

"Calvin (cracking an egg above the stove with only one eye open): The secret to making life fun is making little challenges for yourself.

Hobbes: Like the challenge of explaining the stove and floor to your mom?

Calvin: Rats. See if there's another carton in the fridge, willya?"

- Calvin and Hobbes

Pastime reserved for the hardcore. You see, most gamers don't have unlimited funds, and are disappointed if their most recent $50 investment doesn't require and reward a month's worth of attention. However, thanks to the gradual demise of Nintendo Hard over the years, it's becoming increasingly difficult to milk that kind of commitment out of most new games, which can be completed in a weekend without much effort (well, by the hardcore).

Enter the Self-Imposed Challenge.

A Self-Imposed Challenge is a playthrough of a game wherein the player plays under a restriction not required by the game itself in an attempt to increase the difficulty (or immersion) and replay value. These restrictions can range from the fairly simple (a refusal to make use of a Game Breaker, for example) to the near-impossible ("Hey, can you beat Super Mario Bros. without pressing the "B" button?"). Check a message board for a game that's been out for a while and you'll undoubtedly find players reporting on their progress in various exotic Self-Imposed Challenges.

Gamers will occasionally record these runs and post them on various archive sites. As noted above, the rise of Casual Gamers make these even more of a dedicated pastime than ever before.

Examples of common Self-Imposed Challenges:


 * Hundred-Percent Completion
 * Low-Level Run
 * Minimalist Run
 * No Damage Run (Also covers the easier variants No Deaths and No Continues)
 * No Casualties Run
 * Pacifist Run
 * Solo Character Run
 * Speed Run
 * Stealth Run
 * No (or default only) armor and or no weapons
 * Alternatively, restricting yourself to a single type or category of weapon, if such categories exist.
 * Double Play

Some of these can overlap.

This type of gameplay is one of the staples of the Challenge Gamer. See also House Rules. I Am Not Left-Handed is an in-universe example of this, or rather, an in-universe example of giving up on a Self-Imposed Challenge.

Action Adventure

 * Cave Story has a number of these, mainly the 3 Life challenge which is done by not picking up any Heart Containers, and the Basic Weapons challenge, which forces you to only use the three weapons you can't avoid getting throughout the entire game. There is also a timer for Speedruns in the bonus level. By finishing the last level in under 3 minutes you unlock a bonus song heard nowhere else in the game. Completing the last level is in itself an achievement, but finishing it with Minimum Health, Basic Weapons and under the time limit is almost impossible and very much luck-oriented - there is a section where blocks start falling from the ceiling and their locations are completely random. Doing this challenge has been known to test the sanity of some people.
 * What's particularly insane is that Pixel (the developer) seems to have expected people to try the Minimal HP run because every single boss in the Normal Ending Final Boss Rush has attacks that do 1 or 2 damage. That normally wouldn't bother the player, having 40 to 50 HP, but with only 3 HP, these attacks really hurt.
 * The Legend of Zelda Majoras Mask has the three-day-only challenge, where you can only play the Song Of Time once, and that's when you get the Ocarina of Time from the Skull Kid from the first time loop. For a game that's pretty much made of sidequests, it leaves you with barely much to face the final boss with. Did we mention that you'll be rolling and spinning everywhere? And let's not get started on the Zora eggs...
 * It's been done, too. With the entire 2nd Night and Final Day to spare.
 * Think that's good? Try it gathering SEVENTEEN non-transformation masks.
 * A significantly less insane one is, once all the masks and Heart Containers have been collected, to try and help as many people as possible in one cycle. It helps that, once Link completes a dungeon, he can go straight to the boss on subsequent visits.
 * Also in this game, beating the boss Twinmold using only the sword (no Giant's Mask).
 * Another popular challenge for most of the Zelda games is the three-heart challenge (impossible in some of the games in the series, as you are forced to collect some heart fragments), which is exactly what it sounds like: beat the game without collecting any of the Heart Containers that increase Link's Life Meter. This is easy at first, but quickly gets more difficult as you tackle later dungeons and the game expects you to be able to take more damage than you can...
 * A friend of mine did this on his first playthrough of The Legend of Zelda Twilight Princess. Without using any faeries. Including the Cave of Ordeals. He had to quit without saving (losing progress) quite a few times to avoid collecting heart fragments in chest...
 * The hardest challenge for Twilight Princess would be as follows: 3 hearts, no shield (burn the wooden one as soon as you can and never get a metal one), always using the ordon sword (except for the 2 fights where you NEED the master sword) no hidden skills (besides ending blow), nothing in your bottles, never take off the Zora Armor (anything fire/ice pretty much one-shots you) no bomb/arrow upgrades, no arrows except during bosses and puzzles that specifically require arrows, and lastly, No Sidepaths, No Exploration, No Freedom.
 * It was theorized that the original The Legend of Zelda could be beaten WITHOUT USING THE SWORD (because you have to get it yourself). This is actually impossible, although it is possible to beat the entire game except the final boss (for whom a sword of any sort is required). Using the sword only on Ganon has remained a popular challenge. A three hearts, minimal sword challenge turns this Up to Eleven.
 * Link to The Past is a good example of a game in which to attempt this, and due to an easter egg, when the Master Sword is seemingly required to deflect Aghanim's beam back at him, one can use the Bug-Catching net instead.
 * Also, completing a Zelda game without ever dying is a challenge, because some games such as The Legend of Zelda a Link To T He Past have a counter for number of deaths. This feat is acknowledged in The Legend of Zelda Links Awakening, which includes a special addition to the ending sequence if you complete it without dying. This is extremely difficult in the original NES game, though, because you can only save at the Game Over screen, meaning you'd have to play through the entire game in one sitting.
 * The Oracle games feature the Cursed Ring, which halves your sword damage and doubles the damage you take, it seems to have been made for this trope.
 * The Legend of Zelda Skyward Sword features Hero Mode, a mode where you take double damage and enemies can take more damage, and the enemies never drop hearts (but your sword beam starts off at its endgame strength). Now try playing the mode without potions, extra heart containers, upgrades and any medal, and using only the most basic shield available(or no shield at all). And no using the Sword Beam either, except when it's absolutely needed. Go ahead, try it.
 * With the dawn of Castlevania games with inventory systems and equipment, the idea of "Naked" runs stand out as an obscene challenge that requires no weaponry, armor, magic, or equipment that boosts anything by luck. It gets quite difficult at times.
 * Lets not forget the 1-kill playthrough of Symphony of the Night, requiring you to kill ONE enemy throughout the entire game. You're still beating it at 200.6%; you're just limited to killing a puny Blademaster. This is quite difficult, as the mandatory boss fights count as kills. Once you become extremely adept at glitching through walls, its not terribly difficult, but it will give you a run for your money if you arent mentally prepared.
 * An Untitled Story allows and encourages to do self-imposed challenges. Finish as fast as possible! Complete with highest completion percentage! Finish collecting as least as possible! Finish while saving as much as possible! Finish without saving!

Action Game

 * A popular God of War challenge is the NUR (No Upgrades Run) which is Exactly What It Says on the Tin. Less famous but even more sadistic is the Pain+ run This has been done for every game in the series by various authors on YouTube.
 * Devil May Cry 3 and 4 encouraged players to take on self-imposed challenges in the form of getting the "S" and "SS" after-mission rankings in order to collect bonus artwork completely unnecessary for gameplay. In 3, the most difficult-to-get one required a No Damage Run on top of making the time limit, collecting enough "Red Orb" currency, getting enough "style" points and using no items. The famous player Keith "Pokey86" Poke pioneered the idea of the "Dante Will Die" run, which is a run on the highest difficulty of "Dante Must Die"... with a fresh game, lacking the usually maxed character that would normally be used. It really forces players to use different strategies, given the lack of moves and weapons that would normally be available. Even more crazy and skilled players have combined the SS run and the DWD run.
 * Die hard fans of the first game also like performing fresh runs on Dante Must Die. It's worth noting that, excepting the last few boss fights, it's much easier compared to DMC 3, simply because DMC 1 doesn't beef up the enemies' vitality and defense to the insanity that DMC 3 does.
 * Ninja Gaiden on the Xbox featured a Karma system that encouraged players to gather points. Players then took it beyond what Team Ninja had expected, performing Karma Runs that required ridiculous precision and perseverance. Some have also done no item and No Damage Runs, which unlike aforementioned Devil May Cry are much harder to pull off. Considering the Nintendo Hardness of the base product...
 * The game also features an extremely weak (well, initially weak...) wooden sword weapon. Naturally, people decided to see how far they could get using only that weapon. For example, check out this video of a player beating one of the hardest bosses in the game using only that wooden sword and Ryu's kick attack.

Beat'Em Up

 * God Hand has a built-in Self-Imposed Challenge: early in the game, the hero has a "Kick Me" sign slapped on his back, which makes enemies stronger. It will fall off if he uses the God Hand or God Reels. Finishing the game with the "Kick Me" sign still in place (that is, never using those powers) unlocks a bonus: a music CD.

Collectible Card Game

 * Variant formats for Collectible Card Games may be considered a form of Self-Imposed Challenge, especially those that aren't supported for Tournament Play. Magic: The Gathering, for example, has Rainbow Stairwell, in which the player's deck must contain six cards of each color, one of which costs one mana, another which costs two, et cetera, up to six, and Highlander (AKA Singleton), where players build a deck with no more than one copy of any card that isn't a basic land.
 * Elder Dragon Highlander, a.k.a. Commander, takes the Highlander format and adds additional restrictions: You must include a Legendary creature in your deck, which determines what colors of cards you may play otherwise, and the rest of your deck must be exactly 99 cards.
 * Peasant Magic a.k.a. Pauper requires that your deck either contain only commons, or up to 8 uncommons. Rares are right out.
 * Yu-Gi-Oh!: in the recent "world championship" games, some of the Duel Point bonuses are awarded for unconventional deck compositions. These variants include: no traps, no spells, only 1 copy per card, only 1 type or attribute of monsters, monsters of each possible level, only level 1 monsters, and no monsters at all.

Edutainment Game

 * Oregon Trail: Forget braving the wilderness, there are people who'll try to kill all their party members before reaching the first fort, usually by doing normally stupid things such as fording rivers that are above fording level, not treating injuries, and getting themselves shot on purpose.

Fighting Game

 * The Super Smash Bros. games distribute points based on your performance in battles; high points for playing well, and you can actually lose points for relying too much on a single move. Unless, of course, you only use a single move, or any number of other self imposed challenges. One of the trickiest was called "Switzerland" and asked you to finish the round without ever attacking or taking damage.
 * No More Heroes has the interesting challenge of completing the game using the most basic weapon, the Blood Berry. This can range from being mildly easy on Sweet to insanely hard on Bitter. On Bitter, towards the end of the game, bosses can have around 400% more health than normal, and even mooks become walking brick walls.
 * Fortunately, there are several One-Hit Kill moves a player can use on mooks, which become nearly essential in the later stages. However, bosses are immune to these moves.

First-Person Shooter

 * Half-Life Two challenges you to complete a level using only the gravity gun. Episode 1 ups the ante and challenges you to fire one bullet throughout the entire game: to shoot a lock off after you get the pistol.
 * The Vidmaster's Challenge in Marathon, complete with charter that appears when attempting to use the Skip Level cheat. Rules include using grenades whenever possible, punching every switch (instead of pressing the action button on them), not to use the default Caps Lock key as the run key (i.e. not using what today would be an Always Run option), and to never ever leave a single one of the allied humans ("Bobs") alive.
 * Another is the Fists-Only on Total Carnage (hardest difficulty) - especially impressive on the special Vidmaster's arena level, with the grey enemies.
 * Golden Eye 1997 and its Spiritual Successor Perfect Dark feature unlockable difficulty settings (called "007" and "Perfect Dark" respectively) that allow the player to alter the challenge by fine-tuning certain enemy properties: their health, accuracy, damage and reaction times. Level runs done with minimum enemy health and all other settings on maximum (meaning both player and perfectly-accurate guards will die in a single hit) are known as "Licence to Kill" (LTK) settings. Runs with everything set to maximum, so that guards have ten times more health than normal, are known as "Dark LTK" runs. In Golden Eye 1997 this is stupidly hard since a dead foe doesn't drop enough ammo to kill the next one; in Perfect Dark it's marginally more manageable thanks to the game's quirk that headshots on unshielded NPCs are always instant kills.
 * The above customisable difficulties (as well as the standard ones) can also be used in conjunction with the games' many unlockable cheat options. "Turbo Mode" has obvious effects on the sort of record times that can be attained, while "All Guns" and other weapon options allow the player to impose even more restrictions (it's particularly fun trying to kill all guards in a level using nothing but duel-wielded throwing knives). However, some of the cheats make the game much harder, such as the "Enemy Rockets" cheat, which gives every enemy in the game a rocket launcher with infinite ammo. Yes, that too is possible to complete.
 * And what's more, at the end of each level, various statistics are displayed about your performance. So, can you do one or more of the above... but with 100% accuracy? And within a certain target time?
 * The utterly crazy Doom fanbase. Among the challenges on offer:
 * Speed: Your standard speedrun. Currently, the lowest recorded time for a completed level is five seconds.
 * Pacifist: Complete a level without directly or indirectly harming monsters, effectively restricting the player to causing infighting.
 * Fast: Complete a level while the monsters are faster than normal.
 * Respawn: Complete a level killing every monster at least once in an environment where they respawn.
 * Max: A speedrun where all secrets must be collected.
 * Tyson: The level must be completed with every monster killed as quickly as possible...with no weapons other than the fist, the chainsaw and the pistol.
 * Deus Ex. Pacifist Run is pretty standard, and the game encourages it. How about a no items run? (Not just the first level.)
 * Deus Ex: Human Revolution can also be beaten with a pacifist run. The Missing Link DLC has a more difficult one: No weapons, explosives, or Praxis Kits (augments).
 * Try a No Bullet Time run of FEAR on Extreme difficulty. The former earns you the "Real Time" achievement.
 * Left 4 Dead and its sequel has both fan challenges and in game challenges via achievements. Some in-game challenges involve completing a campaign without any survivor getting incapacitated, using pistols only, using melee weapons only, finish a game without ever causing friendly fire, etc. Some fan challenges include playing a whole campaign on Expert difficulty without any bots helping you.
 * The sequel's Mutation game mode adds different challenges for players to tackle. Challenges include the whole team being forced to use swords only, doing a solo run with the Magnum only, playing a VS game where all special infected are buffed up Jockeys, and many others.
 * Some people have tried a "melee only" run in where you're only allowed to attack zombies by meleeing them to death. The only exception you get is for the Tank where people are allowed to set it on fire.
 * The sequel even has an achievement for this called "Confederacy of Crunches." Well, two, technically, since killing the Tank with melee weapons ("Tank Burger") is going to come up sooner or later if you take this on.
 * Officially, JFK: Reloaded is about trying to recreate three hardest three shots in American history. In reality, it's used for either causing as much chaos as possible, or pulling off trick shots, like shooting off the first lady's hat, hitting a special agent in the ass, hitting Kennedy with a ricochet, or shooting Governor Connally's hat out of his hand.

4X

 * The flexibility of many 4X strategy games with regard to Self Imposed Challenges is almost limitless. Some of the more notable variations include:
 * One-City Challenge: Complete the game while maintaining only one city (base, planet, etc.) Mostly used in games where there is an alternative to global conquest or where cities can be easily razed.
 * No Tech Trading: Your faction must research all of its own technologies.
 * There is another far more useful reason for this option; stopping the AI begging for tech, then getting uppity at you because you didn't give them free toys.
 * No Wars of Aggression: Your faction must never declare war and may only wage wars in self-defense. Conquest is allowable only to reclaim territory previously lost to another faction.
 * The Civilization community has the long-established challenge of "Always War," which is Exactly What It Says on the Tin: You're always at war. This can mean "You're always at war with at least one other civilization" or "You're always at war with everyone." Naturally, when Civilization IV decided to recognize Always War along with the One-City Challenge and No Tech Trading in-game, they opted for the latter form. On the other hand, they also offered "Always Peace," which is also Exactly What It Says on the Tin: No A Is will declare war on you, and you can't declare war on anyone.
 * Speaking of Civilization, Revolutions has a few Achievements for this. "Absolute Power is Kind of Neat" means playing the whole game under a Despotism (the simplest and worst form of government, by near-universal consensus).
 * No Trade Initiation, which makes it much more difficult to exploit the AI which can normally be done one way or another in most games. For added danger, agree to all proposals made by the AI.

Hack and Slash

 * Diablo has its very own sub-community based on the premise of "variant characters": characters obeying special rules. The indisputable kings of these variant characters are the Naked Mage (no armor, no weapons, just pure magic), the Beyond Naked Mage (whatever armor and weapons you like -- providing they're all cursed), and the Barbarian (non-magical weapons and armor only -- no magic, no spells, no potions, no fear).
 * One player had a character called IreneTheInfirm: a hardcore sorceress who could not wear or wield anything, cast any spells or assign any stat points, and was thus limited to punching away for 1-2 damage a go, using the act 1 mercenary as the main source of damage (who also couldn't use any items). Somehow, Irene ended up killing Andariel.
 * In Diablo 2, a user on the inc.gamers forum demonstrated the story of Anna Goanna. She was an Amazon-class hardcore, as in "if you die you die permanently," character who completed the game on all difficulty levels with only cracked/low-quality items, a summonable NPC support fighter and a hireling fighter. Some bosses took hours to finish. When she finally beat the last boss on the Harder Than Hard difficulty, her name-personalized cracked sash sold in-game for multiple high-value items.
 * One player, going by the name Sirian, decided to create a whole host of restricted D2 characters, such as Ember, the firebolt-only Sorceress.
 * Several challenges have popped up in the Monster Hunter series once they have their strongest set of armor and weaponry. The most common are the naked run (no armor at all), to use a really bad weapon against a certain monster (Greatsword vs. Plesioth, no felynes), a marathon run (specialized quest that require you to kill 2 or more of a certain monster simultaneously) and the Arrowhead Cutoff (using only the Circle attack of a Bow, which swings one of your bolts like a makeshift sword, to cut off the tail of a monster, most often a Tigrex.)

MMORPG

 * These even exist in MMORPGs. City of Heroes has the MAN challenge. Essentially, attempting to see how far you can get without using any superpowers beyond "Brawl" and "Sprint." It's considered cheating (and probably rude) to join teams and leech XP from more conventional characters. Due to the way mission enemies spawn, other MAN characters are fine if you can find someone else to join in your insanity.
 * City of Heroes also added an in-game version in late 2007 with the Flashback system. A character can revisit old or outleveled story arcs and complete them with various restrictions, including a time limit, powered-up enemies, or only certain powers and abilities allowed.
 * City of Villains has the "petless Mastermind". Masterminds are the "pet" job of the game, and as such playing one without any minions is really, really hard.
 * World of Warcraft has at least one example in the melee-only hunter (a class normally used primarily for ranged attacks), where the player refrains from using any ranged weapons whatsoever. Gweryc is probably the most well-known example.
 * There's also a player who levelled without any weapons or armour, and at least one pacifist.
 * Leveling a priest as holy used to be this, though it would get you huge friends list when you hit max level. Recent changes have made holy considerably more efficient for basic questing.
 * The Iron Man challenge has recently gained a lot of popularity for WoW. The basics are that you may only use the worst gear in the game (no magic items at all), you can not spend talent points to improve your character, you may never trade with another player to get any stuff, and a lot of other more or less ridiculous requirements. And the big one: if you die, you're out.
 * The webgame Kingdom of Loathing has one of the best-integrated self-imposed challenge systems, featuring (once you beat the game) the option to restart with any of the following restrictions: Cannot consume food (which normally lets you use more adventures per day), cannot consume booze (ditto), Oxygenarian (combination of both), Hardcore (cannot receive outside help from virtually any source), and Bad Moon (which dumps you back at the start with none of your items or familiars from previous games, in addition to being in Hardcore and occasionally subjecting you to adventures which give you advantages that are counterbalanced by disadvantages). If you successfully complete a game under these restrictions, you'll obtain special items at the beginning of your next game, such as extremely potent food items or powerful equipment.
 * Another challenge is the 100% Bad Moon Black Cat run, where in addition to being in Bad Moon, you must find a Black Cat, make it your familiar, and use it for every combat. The cat doesn't like you using skills, steals your MP, decreases your stat gain and blocks you from item drops. The reward for this is the permanent ability to play Bad Moon. Keep in mind that unlocking Bad Moon in the first place requires its own Self-Imposed Challenge of completing a hardcore run without using any ten-leaf clovers, and this only unlocks it for your next run unless you follow the additional steps to permanently unlock it.
 * Of course, since clovers don't drop in Bad Moon and you can't access your items from previous runs, you can always follow one Bad Moon run with another one (unless you retrieve your items and use a clover for some reason after freeing the King but before Ascending).
 * The 'Bees Hate You' run, where enemies with the letter 'b' in their name are tougher, equipment with 'b's in their names hurt the PC at the beginning of every fight, you cannot use any consumable items with a 'b' in their name, except for quest-specific ones, that now deal damage when used, and tough bee enemies will randomly appear.
 * Bees Hate You is the first seasonal challenge path, where every three months there is a new one. If you complete a challenge run when it is still is season, you get enough karma to get you halfway to a new permed skill. Another example is the Way of the Surprising Fist, where you can get virtually no money and can't use weapons.
 * Guild Wars has several types of Bragging Rights Reward completely nailing this Trope. Level Grinding to the maximum level in the Forced Tutorial of Prophecies where you can only get XP past certain point by leveling monsters on your character to point where they become high enough level to grant you xp for killing them, getting the maximum level without dying even once (and getting XP worth of 10 times reaching maximum level without dying.), completing all missions with bonus in the Nintendo Hard mode to name a few.

Platform Game

 * Super Mario Bros. games can get harder by avoiding power-ups. Avoiding everything but mushrooms is good; avoiding those as well is basically a No Damage Run.
 * Super Mario World in particular invites the challenges of not using Yoshi and not visiting the Switch Palaces that activate helpful blocks in other levels.
 * Or even worse, try playing it without getting ANY non-manditory stage points. Raocow is doing this right now.
 * Super Mario Kart allows players to shrink their characters on the select screen as if they had been struck by lightning or a poison mushroom. This way they're slower and more easily crushed, ratcheting up the challenge of an already hard game.
 * Find a hidden green mushroom in Super Mario 64 and collect the 8 red coins and the star before it catches you. That mushroom will not stop until it grants you an extra life.
 * A minor example: Try to beat as many New Super Mario Bros. levels as you can using the turtle shell dash for the entire level. Fun times.
 * How about this: try to beat every single level with a single turtle shell, and restart from the very first level if you get hit. At all. You'll need to start after you've found a turtle shell, though, so you'll have to play a little ways into the game at least to try it.
 * Also extremely fun in New Super Mario Bros.: Complete as many levels as you can ducking the entire level. It's surprisingly easy to do this on the final level, but that's one of the few levels where it's easy.
 * Never forget Buddhist Mario, where you kill no enemies, collect no coins, and have to walk through the gate at the end to show humility.
 * This guy does a parody challenge run of Super Mario Bros. Unfortunately, he fails before even pressing the Start button.
 * Metroid players seem to love self-imposed challenges. Super Metroid in particular seems to attract them besides the traditional Speedruns, low-percentage runs and 100% runs, there's also runs where you don't collect some items usually required to progress, morphball-runs (only get out of morphball when it's absolutely required), and ofcourse the NBMB-run (no bosses/minibosses), where you see how high percentage of items you can get without killing any bosses (it's possible by exploiting sequence-breaking bugs in the game). Here are a few popular, obscenely hard challenges:
 * The original Metroid without beating the minibosses. You get into Tourian by freezing an enemy. Then the Metroids kill you a whole damn lot.
 * Return of Samus with just three items: bombs, ice beam, and one energy tank (the final boss is impossible without it). Yep, you can climb all those open vertical rooms with only bombs.
 * Super Metroid, 11% completion. You need glitches to reach Mother Brain. And man, good luck with Ridley.
 * Fusion, 1% completion. This only works because required suit upgrades don't count toward your percentage. It's actually possible to get zero percent, but skipping that one missile tank (affectionately known as "Bob") requires such precision that it has yet to be pulled off on a real GBA, as opposed to emulators with slowdown functions.
 * Any of the Prime games on Hard with the minimum collection rate. (For instance, the current minimum for Prime 3 is 22%.) Hard mode in these games is murderous; without your stuff, it's strictly for the hardest of the hardcore.
 * Zero Mission is the first (and to date, only) Metroid game that was designed with self-imposed challenges in mind. 15% item completion and a finish time of under 2 hours is required for the best ending, but the item completion can go as low as 9% (10% on hard), and the time to well under an hour.
 * A fairly common one in the Mega Man classic and Mega Man X series is to defeat all the robot masters or mavericks using only your arm cannon, without using an Emergency Energy Tank. For extra challenge, use no charge shot and battle all the bosses and Wily/Sigma fights in the castle levels in this fashion as well. For the truly determined, try taking no damage at all. Exceptions must be made for those bosses who are only vulnerable to a specific weapon. Difficulty can vary wildly between games, from "Slightly more challenging but fun," to "Borderline impossible."
 * As an example of "Borderline impossible", let's player HideofBeast has done a minimalist, no damage speed-run of Mega Man X4-6 on Extreme mode. The X6 run in particular looks so painful to pull off that just watching it could be considered a masochistic activity.
 * Powered Up, the remake of the first game, acknowledged the "arm cannon only" variant; defeating a Robot Master with just your arm cannon will unlock them as a playable character.
 * Youtube user RoahmMythril has actually finished every Robot Master stage in the main Mega Man series, Mega Man & Bass, Mega Man Powered Up and the Gameboy games without taking damage, using only the uncharged arm cannon as far as possible.
 * Mega Man 9 and 10 both have an item called "The Book of Hairstyles" that can be bought for the ever-so-low price of 20 screws. This item removes Mega Man's helmet, revealing his hair. But wait. Without his helmet, Mega Man takes MORE damage, and if he loses even ONE life, his helmet comes back, thus requiring the item to be bought...AGAIN. If you're looking to obtain the achievement for beating all 8 bosses without your helmet, expect your screw expenses to overflow to be screwed over.
 * Thanks to people who spent their time figuring this out, there's a not-so-obvious Mega Man X challenge: Beat the entire game without any upgrades from the get go. Unfortunately, since it's not possible to defeat Chill Penguin without running into the Boots upgrade (or it is, this editor hasn't figured that out), it's technically not from the get go. The password you need is: 4764 8488 7716. To make this even more fun, try without using boss weapons.
 * The Kirby series leaves itself open for these. One example is to not use Kirby's copy abilities, either for an entire game or the duration of one boss battle. Another is to not take any damage while fighting a certain boss.
 * A challenge among Let's Play'ers is the "Haddaway Challenge," thought up by Cloud8745. The LP'er must play Kirby's Dreamland on Extra mode...while listening to "What Is Love?" by Haddaway the whole way...and singing it on its first loop.
 * Kirby's Dream Land features the Config Mode, which lets you adjust how many lives and how much health kirby starts out with. Combined with the above challenge, it is absolutely brutal. Good luck with the Boss Rush in the final stage.
 * Iji has loads of this, some even implemented in-game. The hardest difficulty, Ultimortal, limits you to only upgrading your health - meaning you'll have to stick with the first weapon, the shotgun, for the entire game until the final boss. The game encourages a Pacifist Run, as morality plays a large part in the story. There's an optional timer for speedruns. Right before the final boss, if you've already beaten the game at least once, there's a computer that supercharges his shields, giving him loads of health.
 * Not just loads of health; it kicks him up to 'full power', increasing the rate and power of his attacks, the number of projectiles and the size of their hitboxes, and so on. You are specifically warned that doing this is a very bad idea if you don't know what you're doing.
 * Expert players of Spelunky have attempted many different flavours of this. There's the common stuff, like speedruns, no-damage runs, high-treasure runs, and so on. The game has some built-in optional challenges which unlock stuff, but these are generally considered extremely easy. That is to say nothing of the no treasure, no kills, no action button, no damage runs in Gates of Hell Spelunky that people have attempted.
 * Try playing a Ratchet and Clank game without ever buying ammo from a vendor, i.e. ammo crates are your only method you have of reloading weapons. For added challenge, never use a max-level weapon, and play on the highest difficulty, if possible. Warning: In the games where ammo doesn't reset if you die, this becomes a major case of Unstable Equilibrium, the more you die, the harder it gets. Doing this in Deadlocked on Exterminator difficulty is next to impossible.
 * Rolling Thunder has been completed without the machine gun.
 * The flexible sequence of La-Mulana lends itself well to many self-imposed challenges, which range from the easy (no Scalesphere/Ice Cape? Pfff) to the murderous (No Life Jewels?!).
 * Yoshi's Story has an "official" self-imposed challenge, the Melon Run. This requires eating all 30 Melons hidden in a level. The game goes out of its way to encourage this behavior, and it is the way to get high scores on levels.
 * However, there's also the Thirty Lucky Fruit challenge, which is more true to the trope. This challenge requires eating 30 Lucky Fruit instead on a level. However, each level only contains 12 Lucky Fruit normally. The way to get the others is via an Easter Egg: When you do a Ground Pound near a Shy Guy while invincible, it turns into a Lucky Fruit. Actually making sure you're in the vicinity of several Shy Guys while invincible is another story entirely. It's not even possible on all levels, or with all Lucky Fruit on a particular level.

Puzzle Game

 * Fantastic Contraption, a flash-based physics-puzzle game, lends itself to this. Players will try to complete the goal with as few pieces as possible, or without using certain kinds (gravity power, no catapults, etc.). The fact that you can save and share your contraptions for others to watch in action aids in this.
 * A popular challenge among Japanese Tetris players is to stack blocks to form a stack as wide and tall as the playing field, but with holes in it that form the shape of a "greater than" (>) sign. In the Tetris: The Grand Master series, if you successfully form at least half of the stack, you'll get a secret grade proportional to how complete it is. A textbook example of someone completing this challenge can be seen here.
 * Western TGM players have also taken to playing one-handed.
 * Many people have completed levels in World of Goo for trying to get either as much goo per level as possible, complete the level with least moves or the shortest time. Often it turns the gameplay into something completely different.
 * FreeCell: The most obvious one is reducing the number of free cells, sometimes even to zero (69 out of the original Microsoft 32000 can be solved with no freecells). Some software implementations will have this as an option. Another is to make the biggest "flourish" you can. There are a few games where it is possible to set up a 52-card flourish, taking the home row from empty to full in one move flat.
 * It is possible to complete a lot of co-op chambers in Portal 2 without any help from a partner (as in they don't place a portal or interact with anything) and very few of them require glitches. Finding a partner who will let you do this is a problem, though.

Real Time Strategy

 * It is possible to complete Pikmin without ever getting Blue Pikmin, though you still do need to use them in some sense--there's a flower that allows you to transform a handful of pikmin into blues, but they only appear at very rare points in the game.
 * It's possible to beat Pikmin 2 (collecting 10,000 Pokos) without ever leaving the Valley of Repose. This takes a while since eventually your only source of treasure will be mook corpses, which go for 10-15 Pokos each.
 * Warcraft III allows a player to set the max HP on EVERYTHING they make (units, heroes, buildings, etc.) to be 50%, 60%, 70%, 80%, 90%, or the standard 100% before the match begins.
 * Enter the Day Nine Daily, where we learn to be a better gamer. Except on monday where we just dick around. Indeed, on Funday Monday, the host, Day Nine, imposes a self-imposed challenge on your gameplay such as, "You must only attack on creep", "You must make a planetary fortress at your opponents natural", or "Make all your pylons outside your base." The best and funniest entries are casted by the host on a live stream.

Rhythm Game

 * Guitar Hero 2 and III have a cheat code called "Performance Mode," which removes the fret board, requiring you to play by memory.
 * GH III also has a "precision mode" which cuts down the lax (if not too lax) default timing window to a very picky one.
 * Also, the strumming in GH and Rock Band becomes trickier if you use a pick (or actually strum with your hands, as opposed to gripping onto the strum bar).
 * Instead of using all of the fingers on their fretting hand to hold down notes, some players make things more difficult by choosing to forgo the use of their pinky, or their pinky AND ring fingers, the latter of which is sometimes called 'Django Mode' after the guitarist Django Reinhardt, who only had full use of two of his fingers. Amazingly, at least one player has five-starred every song on Expert using only two fingers.
 * Dance Dance Revolution, in a similar vein, has similar self-imposed customization options for the absurdly hardcore. Would you like to play this dance backwards with no visible steps at several times the normal step speed?
 * If you're playing backwards, then the "increased step speed" doesn't make much of a difference -- it only changes the rate of speed the arrows scroll at. It doesn't change the song's actual tempo. BUT! What about playing with the arrows at an inconsistent scroll speed (Boost/wave), with the pattern randomized (Shuffle), and the arrows appearing -just before they're supposed to be hit- (Sudden)?
 * On the other side of the spectrum, we have actual performance players, who will put out elaborately choreographed routines, complete with knee drops, innovative use of the safety bar, spins and sometimes even flips just for the sake of doing so.
 * To say nothing of the all-Great challenges. MUCH harder than it seems.
 * Or try clearing a song with a score of 0. This basically makes it Good attack. You can't get anything higher, and are only allowed a very limited number of lower ratings.
 * Pop'n Music has even more opporunities for self-imposed challenges. Newer installments have "Challenge mode," which is essentially the game's normal mode, but after picking a song, you can choose up to two objectives to complete within the song for extra "Challenge Points." These challenges range from the tame (such as scoring x points or getting less than y misses) to the not-so-tame (having the scroll speed of the notes multiply or notes do spiraly animations at regular intervals) to the insane (having song characters go into "Dance Ojama" mode and block your view of the notes or completing the song with a perfect score). If you get enough Challenge Points, you'll get an extra stage. Should you desire even more challenge, there's the Cho-Challenge Mode, which is the same as Challenge Mode but with the "Cool" note judgment (in addition to Great, Good, and Bad), which makes scoring Nintendo Beatmania Hard.
 * BMS player Lunatic Rave 2 has a secret option called "Extra Mode". You know all those notes in the background channels? expect to play a lot more of them. To put this in perspective, Scripted Connection (Long Mix) normally has 4459 notes in it. If you're playing an accurate BMS of it in Lunatic Rave 2, Extra Mode increases the number of notes to 6118! (This has the side effect of making some songs nigh-impossible)
 * In O2Jam, playing a song with no speed modifiers (which most players use) is referred to as "slowjamming," and is a commendable skill. On the other hand, in Guitar Hero, using Hyper Speed is the exact opposite and is regarded by many "Stop Having Fun!" Guys as a Game Breaker.
 * HyperSpeed's designation as a player-specific OPTION in Guitar Hero 5 (alongside FOCUS MODE) should remedy the HyperSpeed flame wars. to put it plainly, the player gets to pick what hyperspeed they want for themselves and ONLY for themselves, everyone else is not affected by one player's HS choice.
 * Beatmania IIDX has the Hard modifier, which starts your gauge at 100% and removes the requirement of ending with 80% or higher to clear the song, but it makes your gauge drop much faster with each missed note, and it fails you if your gauge hits zero at any point.
 * This is partially a subversion, particularly where One More Extra Stages (Which require a specific grade with the HARD gauge on a specific song on Another as your fourth stage) are concerned. The Hazard modifier, added in IIDX 16: Empress, is this trope played very very straight, as one "miss" causes you to fail out and scratches out your grade. This means you have to Full Combo the song. Did I mention that some charts have yet to be Full-Combo'd?
 * It's also a subversion, cornering on Unishment territory, concerning songs with all their (fake) difficulty concentrated at the end of the song. If you're a good enough player to hold your own until the ending massacre, the fact that a Hard gauge removes the 80+% requirement can make songs easier to pass than on the regular bar. The EX-HARD modifier, introduced in IIDX 19: Lincle, is much harsher than HARD mode, playing the trope straight again.
 * Recent DJMAX Technika tournaments have employed the "Nobody Knows Next" ruleset, in which each round, instead of just trying to get a high score, you're also required to fill another condition, such as playing with only one hand, playing with only your pinkies, or playing with the machine muted while you listen to completely different music via headphones hooked up to a portable player. There's also the "Miss Attack" challenge in which you try to get as many Misses as possible without failing, and "roulette" mode in which multiple players line up and take turns on the machine on a per-swipe basis.
 * Space Channel 5 and it's sequel leaves room for these. Failure mode where you rescue nobody and get the minimum view rating, Mirror mode is when you play through the game with the mirror code activated... and Purge mode, in which you shoot the hostages and rescue the robots.
 * Stepmania has Song Attacks, or this. This is the game intentionally messing you up.

Roguelike

 * Nethack is worth mentioning as an overarching example: it features a bevy of voluntary challenges, including a Pacifist Run, an "atheist" run (not using the "pray" command to ask favors from the gods, or dropping anything on altars to test for alignment, or chatting with priests, or...), an "illiterate" run (not reading anything, and not writing anything beyond the letter X), a "foodless" run (not eating anything, including non-foods), and for the truly psychotic, combinations of any or all of the above resulting in things like "wishless genocideless polyitemless polyselfless illiterate atheist weaponless vegan" (actually achieved). You get nothing for completing these other than satisfaction, but the game will keep track of what you've accomplished. Nethack is already Nintendo Hard of itself, so these challenges add replay value only for the truly hardcore.
 * It gets even more bizarre when you get into the fan-created challenges. The strangest: "Zen" -- going through the entire game blindfolded. Only a tiny handful of recorded Zen completions are known: samurai (one of the two classes that can start with blindfolds in the inventory), rogues (the other class who can start with a blindfold), and at least one tourist. The tourist used a towel, of course.
 * Most Roguelike games have similar challenges; Angband, for example, has "no artifacts."
 * Another challenge is the Ironman challenge, where you can never go up any staircase, and can never return to the surface by any means, until victorious.
 * There have been attempts to win with no artifacts or ego-items (such as http://angband.oook.cz/ladder-show.php?id=10574 ); none of them have been successful.
 * Ancient Domains of Mystery has an entire series of self imposed challenges, some of which involved the Infinite Dungeon (the only dungeon in the game to not save visited levels, making it similar to Angband). Such challenges include:
 * Ironman: Your typical ID dive. You must use any down stairs you see. The object is to retrieve a powerful artifact from level 67.
 * Leadman: Ironman, only you are allowed to stay on a level as long as you please. Goal is to find the bottom.
 * Aluminum Man: Ironman, only you are allowed to do the Village Dungeon quest first (gives you ~6 levels before you enter).
 * Steelman: Survive in the wilderness, and the wilderness only until level 50.
 * Eternium Man: Never enter a village or city, may not read books in the wilderness. Now; stand in one place in the Small Mountain Cave. This is difficult because the SMC is the most dangerous location in the game: monsters spawn faster and have double your experience (typically a character can fight something up to about 5 to 10 levels higher than he is, depending on what it is--even small white mice get dangerous in the SMC). Survive to level 50, then you can leave. There is only one recorded winner, which got extremely lucky and was able to abuse game mechanics to become A God Am I thanks to lucky spawn.
 * Titanium Man: Complete the game lowest level possible (Low-Level Run). One player ran a troll (which, as the dumbest race, learns very slowly) and finished at level 1, with 86 xp. The only monster slain was Andor Drakon (worth 1 xp, presumably the rest of the xp was from sacrifices).
 * Mercuryman: This one is fun. Use melee weapons as ranged, and ranged weapons as melee. Rocks (an abundant missile) make a great melee item.
 * Goldman: Never spend any money. Be as greedy as possible: any time you see a store you must sell all of your items. You are not allowed to drop or sacrifice any money. Gold is heavy (I hope you find a girdle of greed and bless it).
 * Carbon Fiber Man: Never carry more than 100 stones. An extremely harsh equipment restriction, especially considering that there are five plot-necessary artifacts which each weigh 100s and each need to be brought to the bottom of the Caverns of Chaos, which you have to do while naked in this challenge (and without wearing a signet ring needed to peacefully pass a very nasty monster). Astonishingly, it has been completed at least once.
 * Archmage: Raise a character capable of casting Wish at will.
 * Brimstone Man: Go straight to the Tower of Eternal Flames (guess what it's like), and don't exit until you have the Chaos Orb of Elemental Fire in your possession. Extremely difficult, as most level 1 characters will be burned to ashes within several turns (along with their equipment), and the Tower contains many high-level monsters and a nasty boss. There has been one save-scummed completion, just to prove it's theoretically possible.
 * Dwarf Fortress's Self Imposed Challenges come in four varieties: Self-imposed challenges where players abstain from some gameplay feature like not brewing any liquor, starting build-related challenges like starting with only unskilled dwarves, location-related challenges like building a fort in a place with an aquifer or goblin tower, and megaprojects, which are huge constructions undertaken only to satisfy the player's ego.
 * There is a huge list on the df wiki.
 * There's another, under the title "Stupid Dwarf Trick". Several of them have listed Usefulness ratings of "none", "none, by definition, but highly amusing", "negative", "limited", "questionable", "marginal, but very cool", and, for the underwater statue room, "absolutely, positively none".
 * Particularly notable is the so-called "Hermit Challenge" where 6 of the 7 embarking dwarves and every single immigrant get killed off and caravans are ignored or killed. Check out One Dwarf Against The World, the story that made the name "Urist" popular in the DF fandom.

Role Playing Game
"No evolving your pokemon No dark, Psychic, or Ghost pokemon/moves No Ekans, Arbok, Seviper, or Serperior Pokemon must be LV 22 before they can breed Pokemon of the same gender can not share a daycare center It is your duty to keep any egg pokemon in the party til LV 18 Legendaries are false idols, and should be killed Cant use Fossils, Game corners, or drugs (PP Up, Rare Candy, etc)"
 * Earthbound has numerous 1-in-128 items. These range from items you can't find in stores (such as the Sword of Kings and the Xterminator Spray) to items you can get well before stores stock them. Numerous fan quests have arisen as gamers try to get every one of them.
 * Playing Final Fantasy I with a party of four White Mages is a popular one. The early-level characters are so weak that a battle with goblins can reach epic proportions.
 * Solo quests are also popular, and the truly hardcore will try both -- that is, soloing with a weak class. This is so hard that there are whole FAQs available for beating the game with one Thief, one White Mage, etc.
 * Due to Sequence Breaking, it is possible to reach the Castle of Ordeals much earlier than thought possible, as well as getting the airship very early. This has led to the Level 11 Class Change, which is only possible by running from all battles and fighting only the mandatory fights before Class Changing.
 * Final Fantasy V, predictably enough, has at least a couple to call its own: Freelancers-only, Four Class Challenge, and a popular variant of the latter, the Four Job Fiesta where each character is assigned one class per crystal.
 * Several people have tried going through Final Fantasy VII without getting better weapons or using any materia. Some mixed self imposed challenges are:
 * Low Level, No Materia, No Items
 * Low Level, No Materia, Initial Equipment, No Accessories
 * Lowest Level, No Items, Initial Equipment, No Accessories, No Enemy Skills
 * Initial Equipment, No Accessories, No Escaping, No Physical Attacks, No Limit Breaks, Command Materia Only
 * No Physical Attacks, No Magic, No Escaping.
 * Final Fantasy IX steps up the Low-Level Run to the unique Level 1 Challenge, requiring players to skip and avoid all possible experience in battle, resulting in a Level 1 team against the final boss.
 * The diehard Final Fantasy X community is the king of them all. Not satisfied with the already insanely difficult bonus content, such as the Monster Arena or the Dark Aeons and Penance, there's a massive array of guides on Game FAQs devoted to beating the game with various limiters mixed and matched, from No Sphere Grid (which entails no stat bonuses or new abilities whatsoever), to single character challenges, to the current king of them all, The No Sphere Grid No Summon No Overdrive No Escape No No-Encounters No Blitzball No Customize Challenge, which mainly involves stealing and throwing items with Rikku and praying for certain equipment drops.
 * Final Fantasy VI has quite a few of these. The "Natural Magic" challenge, where you forgo the use of all Espers (or any equipment that offers spells); thus, the only magic that is available are characters who learn Magic through the natural process of leveling (hence the name). This also nixes any form of Esper-based stat boosting, so it is quite difficult. The "CES" challenge is another popular one; you must beat the game using only Celes, Edgar, and Setzer when the game doesn't force other characters onto you. These are the only three characters you must have when assaulting Kefka's tower. Combining CES and Natural Magic is only for the highly skilled.
 * Solo Character Runs with Natural Magic are also popular. Difficulty ranges from the challenging but doable Terra to the near impossible Relm, Cyan and Umaro. Low Level Runs are common, too, through skilled use of Gau's abilities, among other things.
 * And if Natural Magic games aren't hard enough, you can attempt the No Equipment Natural Magic Game(NENMG). No Espers, armor, weapons, or relics can be used at any point during the game, so your characters' ability to deal damage comes ONLY from their natural abilities(Blitz, Rage, etc.). Simply grinding to level 99 is forbidden, and every optional quest must also be beaten, except for the Magi Master.
 * Final Fantasy VIII arguably has the nastiest of these in the form of the "no junction" challenge, sometimes known as "No GF" challenge. No character can ever equip a GF at any time for any reason throughout the entire game. This cuts off access to every skill you get other than attacks and limit breaks, meaning you only get two characters capable of healing your party in any way, get no way to resurrect fallen characters, and no access to the stat boosting junction system which is required to get stats that are in any way passable. Despite all this, apparently somebody did this without resorting to the game's Game Breaker. It apparently took him 200 tries to beat the final boss.
 * Star Ocean: Till the End of Time's Battle Trophy system actively encourages this. You get in-game rewards for beating bosses in under a minute, for beating them without actually moving the player-controlled character, for beating the optional bosses with only one character, for a Low-Level Run, for beating the entire game armed with the game's weakest weapon, et cetera.
 * Star Ocean the Second Story has an option to turn the final boss into a God-like being with insane amounts of HP and spells capable of killing your entire party in a single hit. The game also provides a dungeon specifically designed to help train your party to a high enough level so that this battle won't be completely impossible. But, even at level 255-highest possible level one can achieve-this battle is ridiculously hard.
 * Defeating Unlimited Indalecio is less a matter of level grinding to 255, and more a matter of skill and knowing Game Breaking strategies you can use to bring him to his knees. One effective but somewhat unorthodox strategy requires not using Rena, the best healer in the game, because she can't use Bloody Armor (which grants invincibility at the cost of constantly draining your HP). Instead, use Opera or Noel and have them use full-party heals as necessary. The fight is still pretty tough though because Indalecio flies all over the battlefield while spamming spells and you have to watch everyone's HP so nobody gets eaten by their armor.
 * Unlimited Indalecio is widely regarded as one of the most difficult bosses in any RPG ever made; add in a higher difficulty level ("Universe" mode) where all enemies' strength, defense, blocking ability and health is doubled for a new level of controller-meets-wall. And that's with a full party of mini-gods armed with their best moves and ultimate weapons.
 * Additionally, you can refuse recruitment of all other characters, leaving you with only the two forced upon you (Claude and Rena). Combined with the above, controllers will be snapped.
 * The Elder Scrolls IV: Oblivion has the "Chuck Norris" challenge. You play as a fighter with no weapons or armour throughout the whole game. The Elder Scrolls series is made for this sort of thing.
 * This is easier than it sounds. Hand-To-Hand has some surprising bonuses that other weapons don't, spells can make one very resistant to all types of damage, and not wearing armor makes you practically undetectable when using stealth. In fact, the Monk character class basically revolves around this challenge.
 * There's an additional 'Live Off The Land' challenge, begun by Morrowind players, that requires leaving all possessions and gold in town, traveling on foot, and surviving missions only with what the player comes across. A monk/alchemist build has the most success at making the use of any possible scavengings and loot. This challenge is also doable in Oblivion, but without unarmed skill the player needs to rely on acrobatics, athletics, and arcade reflexes. Also, it's permissible to use alchemy equipment only if left where it's found; looting it means that it has to be left in town, and inaccessible for future adventures.
 * Quite possible in Fallout 3, when using the 'paralysing palm' perk and V.A.T.S (vault assisted targeting system).
 * A blogger named Christopher Livingston decided to play Oblivion as a Non-Player Character, and wrote about it here. PC Gamer magazine later hired him to give Skyrim the same treatment (look here).
 * Fable allows you to bet your money for one or more "boasts" before quests, which include a mix of standard challenges (such as wearing no armor or killing no enemies) and quest-specific ones (such as perfectly defending all civilians). Following them earns you extra cash, while breaking them forfeits the bet.
 * In The World Ends With You, the player can adjust his/her level as preferred; the lower the level used, the better the drops and experience.
 * On top of that, one can get a 100% completion rating from collecting everything that is to be collected, and defeating all the enemies. Though, it has no bearing on your game, other than showing off your game card to someone over wireless connection. Even the noise reports detail all the item drops, collecting them will add a star, which has no effect, except to inform you what it drops, and make it look pretty in the report. You can even fight any of your previous bosses too, on any level and difficulty you're on, and even compete in a boss rush, and fight an absolutely Nintendo Hard boss.
 * Finally, there is the ability to finish the game with only your starting weapon (a badge with the ability of pyrokinesis), no clothes to give stat boosts, and no food eating to increase attack power and defense. The game must be played on the hardest difficulty level available at each stage of the game on level 1, and the 'Retry on Easy' feature for bosses is not allowed.
 * Play the Later Shin Megami Tensei games that have a demonic compendium, but do not use the compendium. Or do a Nuzlocke run of the game.
 * In the first twp SaGa games, using a horribly unbalanced party. Probably the most infamous is four monsters. In the first game, you can simply choose to not recruit anyone, making the Solo Character Run challenge possible.
 * Romancing SaGa; After completing the game once, you are given the option the next time when you fight the final boss; to power him up using the Cosmic Keystone set you have collected; He becomes more powerful, and hits multiple times in one turn. However, the ultimate challenge of this is to offer the entire Cosmic Keystone set to him (10 to be precise). Five and Below means only his HP will increase while beyond Five means his stats will also increase along with HP.
 * This can become even more challenging by adding on a one-character only restriction. The fight reaches near Serial Escalation status. Another popular one is to take on his elder siblings Shirach and Death mano-e-mano both of which can be challenging even with a full party.
 * Try and defeat That One Boss Ewei without Multi Hit techs, that is a real challenge in itself as he regains his meat shields every 2nd turn after both are defeated; said meat shields also protect Ewei from damage. Ewei also uses a Hit All magic spell and he can recover his own HP; and has a magic shield applied at the very start of battle; minimizing the damage dealt to him.
 * Pokémon players can try the Mono-Type, One-Poke, No Evolutions, Speedruns, or Scramble challenges. Scramble entails other players picking your team for you; it's possible to end up with a team of Magikarp and Wurmple, for example. And you can't evolve them. Which sucks for you.
 * Try the Perma Death run: If a Pokemon faints, it gets released. Good luck with the Elite Four...
 * And the "No-Whiteout" challenge. If all of your pokemon in the party faint, start a new save file. Getting that pokedex completion can really suck.
 * A more minor challenge is challenging Gym Leaders with exactly the same number of Pokemon the Gym Leaders use.
 * There's a related version called the "Nuzlocke Challenge", named after the comic of the challenge's creator. The challenge is simple: All faintings are permanent (either via releasing or just keeping them in a box permanently), and you're only allowed to catch the first pokemon you see on any given route or cave. Also, you need to give all the Pokemon you catch nicknames. Completing the challenge? Less simple.
 * There are also optional rules some players add to make it even harder like not using items... or only using items.
 * Another challenge would be facing uber-high level Bonus Bosses using only level one Pokémon.
 * Yes, that is possible. Now try it without Focus Sash.
 * or any pokemon that have the study ability.
 * The Christian Playthrough (though it mischaracterizes some Christian beliefs):


 * One monotype challenge is now apparently known as the 'Youngster Joey' challenge. Get through the Elite Four with only a Rattata.
 * Due to the way the level up system works, it's possible to go through Lunar Knights without any status boosts. This is especially amusing when you can be at level 99 with stats of 1 in everything.
 * Having all characters be the same job is a popular one for Final Fantasy V, and pretty much all of the games that have a job system.
 * Especially having them all remain with the beginning job, which typically doesn't gain new abilities.
 * Vagrant Story has an in-game list of challenges, most of which can only be completed in New Game + mode. These range from using a specific weapon type thousands of times, to finishing the game in less than 10 hours, to doing each block puzzle in record time, to completing the bestiary, to getting the ultimate sword from one enemy in one room of a mapless dungeon, to playing the whole game without saving.
 * Contact can be made so much more fun by limiting yourself to using only one costume and one type of weapon. Since the game only forces you to use other suits/weapons once (Aegis), there really isn't anything stopping you from doing this. A further challenge could be to use the costumes and weapons not designed for battle. Literal Lethal Chef, anyone?
 * Kingdom Hearts: The Critical Mode (Nintendo Hard) Lvl. 1 Challenge with NO DAMAGE for scripted fights, boss fights and Data battles (more Nintendo Hard) from KHIIFM+.
 * Enter Bizkit047, who meets the above description and has more restrictions for several of these fights.
 * Want to get an idea of what it takes to be this good? Watch some of these hard Lvl. 1 CM no damage fights with restrictions: Terra and Saix Data.
 * Xigbar Datawith all these restrictions is simply insane.
 * Do not forget his several hacked fights. One Sephiroth? Make it two. Watch this Xigbar x2 + Xaldin fight. Make sure to look at related videos and look at the other hacked fights from there (such as triple Sephiroth and quintuple Sephiroth/Terra).
 * In Re:Chain of Memories, Bizkit047 also takes up the no HP+ Challenge on Proud.
 * Meanwhile, apulapul2000 has some very good time attack videos.
 * Try beating KHIIFM+ Sephiroth in 37 seconds.
 * 358 Days/2 features an item called the Extreme Ring, which puts your HP down to one, and seems to have been made for this trope.
 * Likewise, because of the game's unique level-up system, Days is quite easy to do a Low-Level Run with.
 * The flexible nature of Baten Kaitos Origins lends itself well to various types of challenges. Given how hard Origins is normally, these tend to be murderously Nintendo Hard.
 * Single character run (those Cross Pendants are a godsend), no specials run, specials-only run, basic attack only run...
 * Since the discovery of a glitch making it possible to skip most of Mercury Lighthouse (where Mia is recruited), "no Mia" runs of the first game have become mildly popular among Golden Sun enthusiasts, along with the usual "minimum Djinn" or "starting equipment only" runs for the rest of the series.

Shoot'Em Up

 * Touhou, one life, no continues, no bombs, quit and restart if you pick up a boost/points, Pacifist Run against the Bonus Boss by outlasting the clock, randomly picked (covered eyes and random clicking, hardest difficulty, and try not to destroy your computer within the first 5 seconds).
 * R-Type skill runs generally involve non-use of the Force Device or Wave Cannon, not killing anything but bosses that would kill you and things that directly obstruct your progress, or some combination of the above. Oddly, the games appear to have anticipated this, since in III, Delta and Final the game will give you a Force Device for the final stage of the last boss if you don't have one. Delta and Final also keep track of various handicaps you might impose on yourself, like beating the game without Force or Wave Cannon.
 * Ikaruga, or at least the Xbox 360 version, actually provides for an entire scoreboard for "Dot Eater" play - meaning you don't fire a single shot, collecting points by surviving and by using your shield to absorb every last bullet you can.
 * Many hardcore Shoot-Em-Up fans attempt to beat Shoot-Em-Ups on a single credit. In fact, one could argue that this is the only legitimate way to beat such a game, since having and utilizing unlimited continues defeats the challenge of avoiding enemies and enemy fire.
 * Certain Shoot Em Ups where it's possible (e.g. the Touhou Project games) have challenges such as No Horizontal/No Vertical, which, depending on the stage or the game, can be deadly hard, if not outright impossible, even on Easy. Others include no Focusing, which requires innate knowledge of the player's hitbox, 1lc, which is not dying at all, 0b1lc, which is the same thing... but no bombing either.
 * For a particularly masochistic challenge, try hacking Embodiment of Scarlet Devil's rank to the highest point, as seen here (or worse) -- Flandre's formerly simplistic non-spell patterns turn into nigh-unavoidable death traps, and her final card is nightmarishly fast.
 * Scoring high in the games itself is a Self-Imposed Challenge. Scoring high in Touhou involves making things as dangerous as possible: grazing thousands of bullets, often using your bombs to clear away bullets, then suiciding to reset your bomb count and get even more points. A compendium of world records can be found at TouhouWiki. If you download the replays on the page, you will be astounded at the challenges the players put themselves through. The world-record Subterranean Animism replay by "yukarin" is particularly notable, getting very close to maxing out the graze counter at 97,585 grazes.
 * Giga Wing is infamous for its ridiculously inflated scores. Some players play just the opposite of the way it was meant to be played; by aiming for the lowest score possible, or even not scoring at all for as long as possible. The latter is essentially a Pacifist Run on steroids; you get awarded points for having bombs at the end of a stage.
 * Zero-score runs are much easier to do in its sequel. Your score multiplier starts at 0, which means you won't score a single point if you never collect a medal. Same with Spiritual Successor Mars Matrix.

Simulation Game

 * Due to its Wide Open Sandbox nature, you can find several Self Imposed Challenges for Freelancer in GameFAQs.
 * The popular Football Manager series of sports management games has a community of players who try to achieve glory with the poorest, smallest, lowest-level teams in the game. They're called L.L.M.ers or Llamas.
 * The Sims 2 community is full of these, because the game doesn't come with hard-and-fast built-in goals. The most common are the Legacy Challenge (keeping a family going for ten generations without cheating) and the Asylum Challenge (filling a house with Sims and only controlling one of them, with the goal of nobody dying of starvation because they didn't think to make themselves some ramen). Even these have spawned sub-challenges and handicaps over time.
 * For those interested a list of just some of the challenges can be seen here
 * The same goes for Sim City in all its forms: while some versions have "scenarios" that give you a goal and a time limit, most players set their own aims for the game in general. As a result, the Sim City community has come up with a number of challenges to keep players entertained when they run out of ideas.
 * Once people are sick of playing Tamagotchi the normal way--to keep them alive and happy as long as possible, they do the opposite; try to kill them off as fast as possible.

Stealth Based Game

 * Metal Gear Solid and beyond was made with this sort of thing in mind, with various ranks and accomplishments. There is the Pacifist Run (which nets you at least a Pigeon rank and is needed to get higher ranks), the Stealth Run (which nets you at least a Chameleon rank and is needed to get higher ranks), and a no-kill no-continue no-Alert Speed Run on the highest difficulty will get you a suitably heroic title, usually Big Boss. There's stranger challenges (like eating all possible animals in Metal Gear Solid 3 which nets you the Markhor rank), and there's still a slew of strange player inspired ones, such as using only the handguns or completing the whole game while smoking a health-sapping cigarette. There's also some very bizarre bonus titles that take a strange mind to get or see the worth of getting - ending Metal Gear Solid 2 with a Ration-eating sea louse in your inventory nets you the Sea Louse rank, and ending Metal Gear Solid 3 with a Stamina-sapping leech attached to your body gives you the Leech rank. Kojima has claimed the reason he included the Naked camouflage in Metal Gear Solid 3 was to 'make players want to finish the game without using clothes'.
 * Various diet-based runs of Metal Gear Solid 3 are popular.
 * Thief players originated the "Ghost Run" -- finishing the game without being detected or leaving any trace of your passing other than missing treasures. Some take it so far as to re-lock every lock. Ghost runners will try this challenge in any other game that it appears to be doable.

Survival Horror

 * Resident Evil 4 lends itself very well to self-imposed challenges. Some of the most popular include the no merchant run, in which the player can only use weapons they find lying around and cannot get any upgrades or bonus items (whether selling excess ammo is allowed varies); the handgun and knife run, in which weapons can be bought and upgraded at will as long as they're handguns; and the no merchant handgun and knife run, in which the player can only use the knife and unupgraded handgun.
 * It helps keep a self-challenger honest that you can just kill The merchant the first time you see him and not risk temptation later on.
 * In general, these kinds of challenges are fairly common in the Resident Evil Series in general, due to the fact that many unlockables can only be obtained by beating the game as quickly as possible.
 * Beat Dead Space without ever touching a workbench. Not hard enough? Try beating Dead Space 2 without ever touching a workbench...on Hardcore.

Turn-Based Strategy

 * Final Fantasy Tactics, already a challenging game with a cheating computer, overwhelming odds and some of the hardest bosses in all of video game history (though strongly mitigated by almost all class having at least one Game Breaker), has a whole FAQ on Game FAQs dedicated to different challenges. It has been completed with one character with a single class and no out-of-class abilities with almost every one of the 20+ classes in the game.
 * It has also been beaten using a single class and no out-of-class abilities with every class, though with a full party. This notably includes the Calculator, whose ability is to cast other classes' magic on all characters fitting certain criteria on the battlefield - but you don't learn any of that other magic in this challenge, and the Calculator "chassis" is weak, fragile, and incredibly slow. Another FAQ was written to tell you how to fight every battle with the Calculators, sometimes all the way to turn-by-turn strategies. It still comes down to pure luck for many of them.
 * The only solo class run that has been deemed impossible is the Mime. The Lucavi boss Queklain/Cuchulainn has no abilities that can be mimicked, so there is no way to damage him.
 * A popular way to mix up your next Fire Emblem playthrough is to limit what units you can use. The most common are lord-only runs, bu these can range from Solo Character Runs to broad restrictions like generals-only or redheads-only. Another common challenge is no-promotions.
 * Archayanami's Female Only Challenge on Gamefaqs. Of course, it's not truly female-only, since you're still allowed to build up your main lord, and if you're playing Hector's story, building up Bartre is also allowed because this is necessary to get Karla.
 * It could be argued that completing a runthrough without allowing a single character to die (which, given that every unit is uniquely characterised and not easily replaceable, is a common practice) is a self-imposed challenge in itself; after all, the survival of only the Lords and mission-specific characters are necessary to progress. And, since many of the games that Western players know autosave after every move made, the player must restart the mission from the beginning if they wish to keep a character that had just been killed. In fact, a playthrough in which all deaths (that don't result in a game over, of course) are accepted could well prove to be a test of the player's willpower.
 * The Jagged Alliance series is fairly open ended, and lets players choose their own method. Most go with the 'get money, buy more guns, hire more mercenaries' approach, but some (more masochist) players will make a drive for the final city with one team, or even with a single soldier. There was even one who attempted to finish the game by sneaking and only using a knife, which can be tricky later on against the hordes of machine-gun-wielding commandos and tanks...
 * Even the Super Robot Wars games are not exempt. Examples: no-upgrade challenges, no pilot improvement (in those games that have it) and for the particularly sadistic, using only a small group of units when not forced to field others, usually from a certain series, such as only using Gundams, only using the ATX team, or only using Tekkamen.
 * Using only Tekkamen doesn't seem too hard, given that they're all ridiculous Game Breakers.
 * The "True to the Show" Challenge forbids you from deploying anyone who was not present in the episodes the scenario is based on and requires that characters only attack enemies from their series (Koji Kabuto is only allowed to fight Dr. Hell's Mechabeasts, for example). You must also finish bosses using the attack that killed them or forced their retreat in the show (for example, you must kill Gentle Chapman with George and Chibodee's Rose Magnum Hurricane). Can be quite tricky, seeing as some series only contribute one unit.
 * In the original Shining Force, it is possible, by making use of a glitch, to skip the first set of characters who are supposed to join your party. Do that, and also skip every single other non-mandatory character, and you'll end up just shy of a full party of 12 at the end of the game. It's a fun little challenge -- not excruciatingly difficult, but hard enough to be interesting. There's an FAQ for this challenge on GameFAQs, though it mistakenly lists Diane as mandatory.
 * A rare multiplayer self-imposed challenge: In Battle for Wesnoth, playing the Knalgan faction and recruiting no dwarves (only footpad, thief, and poacher) is referred to as "HODOR" for no clear reason. The ladder server has a member named HODOR who exclusively uses these tactics, who is nonetheless one of the highest ranked players.
 * To be more specific, HODOR the player (named after A Song of Ice and Fire character) originated the HODOR tactic, thus the name.
 * X-COM: UFO Defense has several possible challenges. They range from simply avoiding GameBreakers such as psionics and blaster launchers, to complex rules such as "only officers can use certain equipment" and "don't sell your superior weapons tech". Also try using only a few soldiers. Or one soldier. Or "Bruce Lee" - 1 man, 1 stun rod. You can even win by attacking only a single alien battleship!
 * The X-COM Util page lists many, such as "don't unavoidably kill, only stun" and "only fight at night".
 * The Antarctica Challenge: Build only one base in Antarctica, the only continent guaranteed not to be in the path of any major UFO incursions.

Wide Open Sandbox

 * A list of Self Imposed Challenges for Dead Rising 2.
 * Minecraft, aside from avoiding the monsters, has no goals and would get boring very quickly if players didn't keep thinking up insane megaprojects to do.
 * Players also do self-imposed challenges with their gameplay style. In reality, a safe shelter can be made by digging 3 blocks straight down and capping off the hole made in the process. However, "How to survive your first night" tutorials usually show much more complex solutions, ranging from a simple hole in the cliff to a small house. The other parts of the gameplay style is also often self-imposed. It's easy to put treasure chests everywhere to minimalize the loss of items after death. Usually that's not done.
 * Some of the challenges players make are more unusual. There's "undercity challenge" where player spends only the first day above ground and rest of the time under ground.
 * Some have actually succeeded in completing the challenge of slaying the Enderdragon in Hardcore Mode, a mode that deletes your save file should you die, so this becomes a no death run. Getting TO the dragon is a challenge in itself, requiring lots of materials, time, and patience, even by normal game playing.
 * There's also the Skyblock challenge, in which you're spawned onto a small island in the sky with one tree, and must complete certain objectives (make a tree farm, make a stone generator, etc) being compounded by even MORE self-imposed challenges.

Film

 * Super Size Me is pretty much one giant self-imposed challenge where a guy goes for an all-McDonald's diet for about a month. He even has his own rules and everything, such as walking 5,000 steps a day, supersizing his food when asked, trying out every single item on the McDonald's menu, and finishing everything on the plate.

Literature

 * In-universe example: Wowbagger the Infinitely Prolonged's quest to insult the entire universe, one person at a time, in alphabetical order. Before you complain about newborn beings early in the alphabet messing up what he's already insulted, keep in mind that time travel is very available in this universe.
 * The time travel part works both ways - he gets messed up due to time travel shenanigans involving Arthur Dent himself (also doubles as a Brick Joke of course...) And he knows it'd be logically impossible - He decided to do it just so he'd have a purpose in life.
 * NaNoWriMo. Write a 50,000 word novel in 30 days.
 * Gadsby, by Ernest Vincent Wright, is a 50,000 word novel that doesn't use the letter "e" anywhere. It was originally written in French without any occurances of "e", and the person who translated it into English maintained this challenge.
 * Similarly La Disparition by Georges Perec, translated from French into English as A Void by Gilbert Adair.

Live-Action Television
"Barney: No one, I mean no one, could get laid wearing these... challenge accepted!"
 * Barney Stinson of How I Met Your Mother frequently challenges himself with increasingly bizarre trials, such as refusing to take off a ridiculous set of overalls until he gets laid.

Sports

 * Reportedly, when the Celtics were facing one of the teams near the bottom of the standings, Larry Bird used to impose these on himself. One common one was going an entire game shooting exclusively with his left hand.
 * Also reportedly, this is how the Harlem Globetrotters went from 'straight' basketball to the colourful antics they're known for.
 * Likewise, mountain climbers may seek to climb all peaks above a given height (possibly in the world, or in a given country, or in a given state/province), the highest peak on each continent, the highest point in each state, etc.
 * Few runners can hope to ever reach the level of winning a marathon, but many set themselves the goal of simply completing one.
 * Cyclists consider completing a century ride their equivalent of running a marathon. It involves biking at least 100 miles in one ride. Even though this has gotten easier with modern low weight, quite comfortable carbon fiber bikes, it's still a daunting enough challenge that most large bike manufacturers release models specially designed for these kinds of rides.

Web Comics

 * This Xkcd inspired an actual Flash implementation of the game. It's pretty unplayable (that's kind of the point) with the usual Tetris goals, but a MeFite pointed out the game is actually interesting and reasonably challenging if you try to end the game with as few pieces as you can.