Unstable Equilibrium

"In order to get a loan you must first prove you don't need it."

- Murphy's Law: John's Collateral Corollary

A design pattern common in many games, an Unstable Equilibrium occurs when there is a design feature in a game that rewards a well-performing player with advantages that help them in later parts of the game.

Like many features, this has its upsides and its downsides. It can create a situation where early advantages accumulate to the point where the game becomes very easy later on. Thus, a player who fails to take early advantages will find the game much harder in the later stages. On the other hand, it also means that early advantages matter, encouraging strong play at all phases of the game, not just the busy late-game where all the flashy stuff is happening.

Competitive games where the winning condition can only be achieved by a critical amount of advantages, like Chess and many strategy games, feature an unstable equilibrium as a Necessary Weasel. No good or professional player will normally make a big-enough mistake that lets the enemy win directly. So you need small advantages that snowball later, because if not, games would stalemate 9 times of 10. However, getting the balance right—the number of advantages, the snowball rate, things like that—is a very difficult design problem.

This article provides a more in-depth examination of the issues surrounding the phenomenon. It also provides some ways of avoid it for those who do not wish to use its benefits.

This can occur in several ways, including the following:
 * In games where the players keep resources (e.g. troops, equipment, money) from level to level, a player who can avoid losing troops in earlier levels will have more to use in later levels, and so be better able to avoid losing troops in later levels.
 * This can be averted by either subtracting troops from the player at regular intervals, or instituting Dynamic Difficulty, so that the strength of the opposition is proportional to the player's own strength. (This can open up its own Loophole Abuse, but nothing's perfect.)
 * Another way is allowing the player to bring along old stuff, but at a price. Like in Battle for Wesnoth campaigns, where rather than recruiting an unit with random traits and 0 XP you can "recall" a survivor from a previous scenario with experience and known traits, but it will cost you more gold.
 * Note that even if compensated, different sets of extra resources allow more possible responses to a challenge, and thus the level could need balancing against a greater set of player strategies. It's hard to escape without plain Bag of Spilling.
 * In Role-Playing Games, the hardest parts of the game will often be relatively early on, when you lack money, supplies, equipment, skills, Experience Points and possibly even party members. As your party grows exponentially stronger, it becomes increasingly difficult for enemies to remain challenging simply by proportionally increasing their strength. There are often also "bonus areas" that are harder than normal areas, but have more powerful equipment such as the Infinity+1 Sword or a Heart Container. Players who can beat that area will be rewarded by having the rest of the game be easier. (It is often observed that anyone who is good enough to get the Infinity+1 Sword doesn't need it to win the game.)
 * This can be averted by smoothing out the party's growth curve and adding new complexity to the combat system over time, rather than giving everything out up front. Instead of relying on "bigger numbers win", create a combat system that forces the player to use what they have in new and innovative ways to win.
 * In many "empire-building" or 4X games such as the Civilization series, a player who conquers more area will have a larger production and research capacity, thus enabling him to get even farther ahead. This often leads to a situation where once one side is ahead, it is very difficult, if not impossible, for the opponent to catch up, and a significant portion of the game can be just "mopping up" weaker neighbors. Games with strategic resources that enable the construction of higher-power units only add to the importance of territory control.
 * The aversion here is to add Variable Player Goals, allowing players to win from behind or by surprise. Even the first Civ game allowed you win by either conquering the world or being the first nation to launch a successful interstellar mission to Alpha Centauri. With proper management, this is possible even if you only have a medium-sized empire.
 * A straightforward, but hard to implement approach is to give the larger empires some costs, whether in upkeep or risks.
 * You always need to protect the borders (which grow slower than the volume of the empire), but without Easy Logistics you may also have to protect the communications.
 * Differences in unit upkeep. E.g. having upkeep cost increase after certain amount of units (perhaps growing with the empire's size, like in Master of Orion 2), so preparing for a war costs more. Different types of upkeep (Master of Magic) may mean that stopgap/presence Militia units may be almost free, champions are expensive both to build and maintain, and having units with special abilities that may be inherently unavailable to the opponents (summons or heavily enchanted) requires to spend a more valuable resource.
 * Another solution is increase of non-linear troubles.
 * Different special abilities. Having more common borders with more unfriendly neighbours means the larger empire cannot easily exploit Tactical Rock-Paper-Scissors: once you expanded, you must prepare to deal with several superior specialists - the stealth-based opponent, the very fast opponent, the heavy bombardment opponent, etc - at the same time.
 * Cut-throat diplomacy. If the default environment is less hostile, having many neighbours increases the risk that one of them may make others squabble with you.
 * Almost any Massively Multiplayer Online Role Playing Game has this trope to some extent, as players who are better will be able to gain experience points faster, thus getting to higher levels faster, making their characters even more powerful. However, the effect on gameplay is mitigated by several factors. First, basically all games with Experience Points guarantee some gain over time; good players just get extra ones. As well, weaker players can team up with each other (or stronger players!) to get help, and players can sort themselves by level, so that a weaker or lower-level character can simply avoid going into more dangerous areas or against much more powerful players.
 * It should be noted that many early MMORPGs had severe penalties for death, so that a player who died ended up with a much weaker character (or one with less equipment), causing him to die more, incurring the penalty again, so on and so forth. For this reason, many newer MMORPGs have eliminated or at least significantly reduced the penalties for death.
 * Space shooters and other genres often feature power-ups that you lose upon death. If you're not good enough to survive when you have a planet's worth of weaponry attached to your ship, you're probably not going to do much better when you're demoted to a single gun that can only have one bullet on the screen at once.
 * Some racing games have "rubber banding" (like Rubber Band AI, but for the player as well) to try to keep this from happening, but depending on how the rest of the game is done, and how the decision to use/not use rubber banding is integrated with it, it can either exacerbate the problem for the player and make the game too hard, exacerbate the problem for the AI and make it too easy, or otherwise mess with the game balance in unintended ways. Perversely, such things can even make being behind for a time a valid tactic, as other advantages are gained from being behind.
 * Some games (particularly Rhythm Games, Shoot Em Ups, and action-adventure games) have a combo system, as well as rewards for scoring high combos (more points, higher attack power, or items, just to name a few). Skilled players can string large combos for massive rewards, but less-skilled players won't be able to make so much out of it. Worse, if there's a break in your combo, your current combo typically resets back to zero. This means a mistake at the beginning or end of a combo is miniscule, but a mistake in the middle is devastating because instead of your combo being somewhere near the maximum you can get, it's now at only half of that. Note that combos usually don't award health or do anything to make the game easier, so this isn't a pure example; it's just that a better player will have a much higher score even if the other player is almost as good.
 * Games where extra lives are awarded for reaching certain point milestones. Better players get more lives, and the less skilled players that have more need for them get fewer.
 * Some First-Person Shooter online multiplayer modes use a reward system, giving players EXP/money for kills, completing objectives, and other such accomplishments. This means the better players get better equipment, allowing them to get more EXP and repeating the cycle.

Note that weakening the instability usually is desirable (to keep the game interesting, rather than "a breaking point plus long mop-up"), but this way treads the thin line between other pitfalls - mostly clunkier game mechanics and Fake Balance elements.

See Bragging Rights Reward and Multiple Endings, which are both alternatives to giving more power to skilled players. Related to Resources Management Gameplay.

Contrast to Rubber Band AI and Comeback Mechanic. See Golden Snitch for one major type of aversion. Opposite to Dynamic Difficulty. Almost opposite to Empty Levels, in which the overall difficulty of the game increases as your character gains levels. See also Hard Mode Perks, which is rewarding the player for simply choosing a higher difficulty.

Truth in Television, since real soldiers do not respawn when killed.

Action Game

 * Very much in effect in Devil May Cry series. Skilled players will use better and more varied combos - giving you a higher style rank. The higher the rank, the more orbs the enemies drop, which in turn allows for you to buy more and better moves, giving you the ability to use better and more varied combos...
 * The earlier games in the Tomb Raider series have items carry over from level to level. Saving health packs and especially ammo during the early levels where enemies still die easily to the infinite ammo pistols allows for a lot more leeway towards the end, where not having enough ammo is likely to also drain your health pack supply. The third game throws a few nasty curveballs in there to mix it up:
 * A certain level empties your entire inventory, and, depending on what order you choose to play the levels in, this could be as early as the 6th level or as late as the 14th. You don't get any of it back. Saved everything you found so far to make the final levels less painful? Shucks.
 * The only exception to this inventory wipe is your save crystals, in the Playstation version. These are collectibles that carry over from level to level and allow you to save your game. Yes, except for between levels, you won't be able to save without them so you'd better not need to save much early on!
 * At the very end of The Legend of Zelda: Majora's Mask you have the option (if you collected all the masks in the game up to that point) of getting the Fierce Deity's Mask item, which transforms you into a badass warrior god with an enormous sword. This makes the subsequent final boss battles ridiculously easy.
 * Bomberman games are notorious for this in its arcade single-player modes. You died? Kiss all of your ability power ups GOODBYE!
 * It's even more painful if you died to a boss; you now have NO chance of getting replacement powerups. Get a Game Over to the Boss? ALL of your powerups are gone now, have fun killing that boss now with only a single bomb with a blast radius of a mere 1~2 and NO way of getting stronger. You may as well start the game all over at this point.

Beat'Em Up

 * God Hand includes a difficulty system that goes from easier to harder and back depending on how well the player's doing, through levels 1, 2, 3 and the aptly named Die. After each level, the game counts up all the enemies you killed and rewards you with money depending on the average difficulty level, and conversely penalizes you for every death. Having more money allows players to buy more powerful attacks and upgrades.

First-Person Shooter

 * Online multiplayer team games such as Counter-Strike often gives the winning team a bigger reward. This, of course, means that as one side keeps winning, the losing team slowly becomes crippled relative to the winning side.
 * Which is why some servers have House Rules such as a side that has lost a certain times in a row may suddenly receive a mysterious cash infusion so that they can afford the same weapons as the winning side.
 * Some servers also run a Warcraft mod where players earn XP for kills. Higher levels get better abilities, which may make it nigh-impossible for low-level players to get any kills. For example, an Orc player at a certain level has the explosive power and range of regular frag grenades boosted by a factor of 2-4. This can allow and Orc to clear out an entire building with a single grenade. While some servers keep your XP and level if you log out and come back later, other servers reset it either upon a login or at certain intervals.
 * A similar problem occurs in multiplayer games where the players have to collect weapons and powerups like Quake and Unreal Tournament. A recently killed player will be severely understocked against the player that just killed him, which in turn leads to worse chances of getting the next powerup that appears and increased chances of dying again.
 * In Unreal Tournament 2004's case, the adrenaline. By getting full adrenaline the player can temporarily give himself regeneration, a faster firing rate, superspeed movement or even invisibility. A good player will gain a massive advantage from these with the most unfortunate example being Bombing Run, a sports-esque game mode where scoring a goal gives a large amount of adrenaline to the player, about 35% of the meter. Since speed is very important in Bombing Run, the winning team will be able to abuse the superspeed powerup over and over again as they score more goals and refill the adrenaline almost instantly.
 * Notably, Adrenaline was disabled in most competitive UT2004 matches, as were the one-shot-kill superweapons. This meant that in competition, the unstable equilibrium feature on a map was usually the large shield pickup. It was a strong enough bonus to ensure that its holder could NOT be killed in one shot by any normal means (though falling into an instant-kill map hazard was still fatal). This item spawned on a predictable timer, and many, MANY matches were decided largely on which player could manage to be precisely at the point where the pack spawned at precisely the moment the shield respawned. The player who had taken the last shield had a ridiculous advantage in taking the next shield, provided that they had managed to retain their shielding. Additionally, as the player's arsenal was emptied on death, the shield-holder often had a wider array of weapons available in any given encounter, where a freshly-spawned player might have held two or even one good weapon. Also, given that certain (usually deathmatch) rulesets made weapon pickups despawn temporarily on pickup, a player with the early lead could conceivably hold a monopoly on the best health items on the map AND the best weapons for depleting that health. It's little wonder that very small skill gaps in UT2004 could lead to landslide victories.
 * In the Onslaught game mode, Power Nodes almost always spawn vehicles. The team controlling the most nodes thus usually has a firepower advantage.
 * Team Fortress 2, as carefully balanced as it is, does this on purpose. On control point maps, a team that's down to a single point still under its control will have its respawn interval increased, making it take longer for a killed defender to rejoin the fight: without this rule, the density of defenders on the last point would be so high that no one would ever win.
 * The game also rewards doing well with critical hits: A few seconds after killing another player, one has a higher chance of scoring critical hits and, therefore, to keep killing. This is to encourage players who are 'on a roll' to stay that way.
 * In Arena and Capture the Flag, the first kill and intelligence captures give the whole team several seconds of all crits, making is easier to push for the intelligence again or get more kills.
 * They go into great detail on the evils of stalemates in the dev commentary. The engineer's teleporter, the moving respawns, and the sliding respawn interval are all bent towards crushing the weaker team, so the match can end and the teams can be reshuffled. It's also interesting to play third-party maps by people who didn't listen to the commentary, and therefore designed a old-style static map, which of course results in a stalemate nine times out of ten.
 * The Modern Warfare series and Call of Duty: World at War also have this - players who get kill streaks without dying are rewarded with air support raining down on the opposition. However, these advantages are SO high as to fall squarely into the main-level trope. Someone who is only okay is likely to get less and less kills, as the high-level people gain the ability to use those tricks.
 * This goes even further in Modern Warfare 2 and Black Ops, as the later killstreak rewards are often simply -better- than earlier ones. A weaker team might be trying its hardest to scrape together enough kills to earn a UAV recon or spy plane, whereas the other team could be grounding them into dust with repeated airstrikes, AC 130 gunships and attack helicopters. Worse, in Modern Warfare 2, said killstreak rewards count towards earning others, something that resulted in the somewhat infamous Harrier/Chopper Gunner/Nuke combo.
 * Curiously this can also manifest within a team. If one or two exceptional players keep killing the outmatched enemy team, their allies can find themselves constantly chasing after blips on the radar, finding only corpses, while their exceptional allies are already on the other side of the map making new corpses of the team who have just respawned. As the best players get better and better killstreak rewards they'll create a situation where only they can get kills, because the enemies spend too much time dead for anyone else to have a chance.
 * In the online FPS PlanetSide, players were soldiers on a battlefield and received experience points for killing enemies, but received much more experience points if their side won a battle. Hence, if one side started losing, players on that side would realize they were unlikely to win and pull out, looking for better experience-point potential in other areas. This meant that it was difficult to find a battle in serious contention for more than an hour or so at a time. To mitigate this problem, the developers introduced a system that gave players on the side with fewer members bonus health and experience points, encouraging them to stay. This also caused controversy among gamers: one gamer said that the game was "becoming more like the University of Michigan every day" (referencing the affirmative-action debate).
 * Counter-Strike tries to partially alleviate this effect by giving the losing team slightly bigger amounts for each consecutive round they lose. Not that it helps much, since the winning side gets bigger awards for streaks, as well.
 * Counter-Strike is a perfect example of this Trope. You buy weapons with money; more expensive weapons are usually better (and with more money, you can afford more weapons, grenades and armor); and you get money for getting kills. Pretty much the entirety of any given map follows from the first round: the winning team gets more money, buys better weapons than the losing team, beats them by a bigger margin the next round, and just keeps getting further and further ahead, until the losers can't buy anything and are stuck with the anemic default load-out while every member of the winning team has an M4, lots of flash-bangs and body armor.
 * Unless the losers wise up, play a round without buying anything, then use two rounds worth of cash in the next round to even the stakes. Doesn't help if there's a massive skill difference, but still...
 * Three other factors make it slightly more complicated: Anyone that manages to survive the round gets to keep their weapons and equipment, and thus only HAS to buy armor(and can thus accumulate a bankroll): it's also very unusual for a member of the losing team to survive(it can only happen if the objective is completed or time expires, but the most common round ending is 'one team is completely dead). Cash is capped at $16000, which somewhat limits the utility of this... but that's still enough for several rounds of good weapons, even if they got paid nothing between rounds, which they didn't. Third is that there are relatively cheap weapons that are reasonably effective, and with some luck and skill can allow a team to overcome a gear disadvantage(if they had skill they probably wouldn't have ended up with the gear disadvantage though!) Cue mods that give all players $16000 at intervals (sometimes as frequently as EVERY ROUND), and admins manually adding cash to the disadvantaged team.
 * Time Splitters brought a creative solution to the problem in one game mode: the player in last place gets a strike team of rocket launcher-wielding monkeys dropping in periodically to help.
 * The sequels have another mode called Shrink, in which players change size based on their rank on the scoreboard: maintaining first place means retaining normal size, but any drop in position causes the player to shrink, with the last place competitor becoming very tiny and difficult to hit.
 * In Halo: Reach, the weapons you have when you blast off in the sabre fighter determine what weapons you have when you board the Covenant Cruiser. On harder difficulties a poor weapon choice can dramatically affect how well you do on the Cruiser level.
 * Same with the two-part missions in Halo 2, where your weapons carry over from the first half of the mission; a poor combination can make things more frustrating, and if you quit and reload, you start over with the mission's default weapons.
 * This trope is very common in many modern FPS' with a leveling system: Kill enough people, level up. Level up, get better weapons. Get better weapons, kill more people. Kill more people, level up faster. Rinse and repeat.

4X

 * Sword of the Stars, being designed as a competitive multiplayer game, tends to invoke this trope. While a small empire can hold off a larger one almost indefinitely by building ships instead of researching, doing so will leave you far behind research-wise, making the outcome inevitable. To make things worse, the game is sufficiently random that you often 'start' with an advantage of this level, and smaller AI empires only band together if they have a decent chance of success - beyond that, they're smart enough to ally with the apparent winner instead. It does cut down on the mop-up period.
 * On the other hand, you can also start with a disadvantage of this level, that you must work to overcome. The degree of randomness in starting positions and the amount of available customization in initial conditions is seen by the developers as an effective counter to the problem of unstable equilibrium, when viewed statistically over the course of a large number games.
 * There's also the problem of the Zuul players having expansion as a racial requirement. As their planets are constantly losing resources, if they're not allowed to expand, the empire will eventually die.
 * Civilization games in general suffer from this when it comes to the research-race. Players who start out in a location favorable to research, or know how to best balance early expansion and enhancement of existing cities to maximize research, will sooner be able to create buildings that increase research (Libraries, Laboratories) and - more importantly - build one-of-a-kind Wonders that can boost research of provide free technologies (The Great Library, for example), thus further increasing their lead in the tech-race. Next thing you know, they'll be knocking over your bow-and-arrow wielding sentries with tanks and tower artillery. Better hope you're playing one of those Civ-games where Rock Beats Laser...
 * Popular Civ4 mod, Fall From Heaven includes this trait, but also adds a new, militarized version in Baron Duin Halfmorn, a unique 'World Unit' which can be built by ANYONE, regardless of civilization, religion and civic choices - the ONLY such unit. (All other 'unique' units are cultural or religious heroes.) So basically, whoever first researches the necessary technology, gets to build him. Being a Werewolf, he has a high chance of turning any unit he kills into a Ravenous Werewolf, and if they survive their first engagement (even if it's only with an unarmed Worker), they turn into Blooded Werewolves under your control. These, then, have a chance of turning into stronger Greater Werewolves with every combat-success - and every type of werewolf has a set chance of creating more whenever they kill a unit. Thus, anyone good enough with tactics to make decent use of Duin Halfmorn and his spawn, are rewarded with even more, free units with similar power, essentially allowing a skilled played to BECOME The Virus. (Fortunately, there's an option to simply disable Duin Halfmorn from your game if you find him too unbalanced.)
 * In Star Trek: Birth Of The Federation, a small empire will invariably be at a disadvantage, as research nets you bigger and better warships. For example, if you play as The Federation (which is, arguably, one of the most difficult factions to play) and dominate research, you will fairly quickly get access to the Defiant-class heavy escort, the most powerful warship in the game (available to the player). No other race has an equivalent. A single Defiant can destroy an entire fleet without sustaining much damage thanks partly to its cloaking device (which gives you a free turn at the start of combat). Additionally, if a weaker empire is constantly losing battles, the planetary morale will keep falling until the planets start seceding, which has further negative effect on morale, resulting in a domino effect.

General

 * Frustratingly, nearly every multiplayer game with easy server browsing and teams of more than four or so can suffer from this due to unsporting, bored, or time-conscious players. Players on the losing team may be able to change sides to the winning team, creating an unbalanced situation just by sheer numbers. If circumstances prevent players from changing teams, then players on the losing team can always just leave the server, which, again, gives the winning team an advantage.

MMORPGs

 * World of Warcraft deals with this in its Lake Wintergrasp PVP area by granting the faction with fewer players present the Tenacity buff, which gives them increased health, health regeneration, and healing power. In extreme cases, this can result in players with five times as much health as the opposition. Tenacity effectively rewards the side that's unable to gather as many players together to fight, since it's widely considered that the buff more than makes up for the lack of numbers.
 * Of course, Tenacity doesn't help defenders because 3 players cannot cover 20+ points of entry from 80 or more players. It basically just enforces a tug of war.
 * There's also a feature in Wintergrasp that makes the battle easier for the attacking side if they've consistently lost several battles, ensuring that control of the zone will eventually switch.
 * Tol Barad has similar issues. There's no Tenacity, and it's much easier to defend Tol Barad than it is to capture it. This is semi-intentional, as capturing Tol Barad comes with huge rewards. They're tweaking it to make capturing Tol Barad somewhat possible, however.
 * Another World of Warcraft example, this one created via an Addon. The infamous "Gear Score" addon calculate the (then hidden) item level of a player's equipment, and assigned them a number based on the average. This was meant to give raid leaders an indication of how well geared a player was, as certain content required a certain level of gear in order to be survivable. Unfortunately, Gear Score really took off, and some raid readers began enforcing "Minimum Gear Score" requirements for certain content. Often, the only way to achieve the required score was by equipping gear found only in the dungeon they were about to run. Blizzard eventually made item levels visible, and began enforcing a (considerably more reasonable) minimum ilevel to run content.
 * EverQuest. Couldn't survive in this zone with your equipment? Have fun trying to survive naked if you die and have to make it to your corpse. In the old days, at least.
 * Obscure German browser game Power of Politics suffers of this. You can challenge other players to debates. Your chances of winning are determined (among other things) by your Ego, Publicity and Eloquence scores. What do you get as a reward for winning debates? Why, a portion of the loser's Ego, Publicity and Eloquence, of course.

Platform Game

 * In the original Mega Man series and its Spiritual Successor, Mega Man X, there are eight (six in the first game) Robot Masters that you have to defeat and you can do it in any order. Each one of them is weak against one of the other's weapon that you can copy. Once you have knowledge of their weaknesses, you can easily cream the rest of them once you beat one of them.
 * But then it's all fair for the final level when you have all the weapons...at least until you realize that dying will not refill your weapon energy tanks, but it will remember which ones you've already picked up. When these weapons make getting through certain parts about 100x easier, and you use them all up, and then die and have to do that part again...
 * Mega Man Zero was worse. In order to gain a new special attack from a boss, you had to get the highest rank in the stage - you had to be good enough to win without taking any dmaage or using any items.
 * The original Super Mario Bros. actually had this pretty bad. Fire flowers made it easy to plow through enemies, including the otherwise tough Hammer Bros and otherwise climatic boss fights. But mess up or fall into a pit and you'll have a much harder time. 8-4 in particular; if you get there as Fire Mario and know your way through, it's not too difficult to preserve that status for the boss and win, but if you get lost, you'll probably take a hit or run out of time before you first make it there, and the level is exponentially harder without the fire suit and there's no way to get one once you're there. Later 2D games also had lots of suits like this, many hidden, so in most games a simple Self-Imposed Challenge is to avoid such suits.
 * The base bosses in Contra(arcade version) increase in difficulty the longer the fight drags on. In Super Contra, if you lose your weapon upgrades in Those Last Two Levels, you're as good as dead.

Rail Shooter

 * The original Time Crisis, and its Gaiden Game Project Titan. Unlike later games, where the timer completely refills every section, it only increases by a certain amount for each area, also depending on your skill. So if you aren't fast and well skilled, you'll have less and less time for the subsequent areas, and when the timer runs out, it's Game Over. The timer also keeps running during the "Wait" sequences.
 * House of the Dead 4 gives you a letter grade at the end of each level based on your overall accuracy, score, and "shot ratings" (number of headshots and headshot streak). Nb., you lose points every time you take a hit. S (which requires an absolutely phenomenal run) nets two life boxes, B (which takes some skill, definitely no gimme) or A earns you one box, and anything worse gets nothing. The result is that there's very little middle ground in this game; either you're an ace and can zip through the whole game in 1-3 credits or you struggle mightily and have to shell out. If you mismanage grenades, can't get headshots, or don't know the layout, be prepared to really pay through the nose.
 * Silent Scope EX gives you a letter grade at the end of each level based on speed, hit ratio, and headshots. An S rating restores 10% life, and a SS restores 25%. Lower grades have proportionately smaller benefits. Needless to say, if you're good enough to SS even one stage, getting through the whole game in a single credit isn't going to be a problem. If the best you can do is B, it's going to get expensive.

Real Time Strategy

 * Sacrifice is one of the more dramatic examples. There is a single resource for creating units; souls. These souls exist in a very limited amount, most held by you, your enemy, and the scarce ambient creatures across the field. Since souls are easier to hold on to (run into them) than they are to steal (a minute long ritual just to get them on their way to your altar for another ritual to convert them) the game maintains a strange sort of stalemate...at least until you lose one bad fight. If your enemy gains even a tiny soul-lead on you, it turns very quickly into a snowballing curb-stomp.
 * Made slightly more odd by the fact that this is the main tactic in the campaign mode for you. Create a catspaws base to start sapping enemy souls for your own army.
 * Multiplayer Online Battle Arena games like Defense of the Ancients, Heroes of Newerth and League of Legends tend to turn one-sided very quickly. When a player is killed, the enemy gets gold and experience and may push the lane and kill a tower; once they get inside your base, their creeps get stronger too. Meanwhile, you're dead and unable to get experience or gold, and in the first two of those three games you also lose gold. Both gold and experience translate into more power for the enemy, making it easier for them to stomp you again next time. This quickly leads to 'feeding': getting killed without killing the enemy in return. And feeding is a one-way ticket to defeat: dying just three times against the same opponents can decide the match in their favor. It can be punishing and obnoxious, but with existing matches lasting forty-five minutes or longer it's probably necessary to avoid eternal stalemates... with the downside being that it can be incredibly annoying to have to sit through the rest of a match when your team has essentially lost it in the first five minutes.
 * This is made even worse by the fact that in a number of these games players actually lose gold when they die- as if giving the opponent gold and exp and losing the opportunity to both farm more and keep the opponent from doing so themself wasn't penalty enough. You might also have the option to "buy out" of a death, which typically costs tons of gold and is only feasible if you're way, way ahead. League of Legends and Demigod are two games which removed this extra penalty (as well as the buyback thing) and even the super-hardcore "Stop Having Fun!" Guys rarely complain about its omission.
 * Warhammer Dark Omen made a downright infuriating example. Lose a critical unit in any battle, and you are royally screwed. In fact, the very instant you see your Fire Wizard drop dead, you might as well restart the battle. Also, if you had high casualties in one battle, that usually meant that your army was not at full strength for next battle, leading to heavier casualties, etc. It quickly degenerated into a downward spiral, where your best option was to restart the campaign and self-impose yourself some "acceptable casualty limits".
 * This is a well-known phenomenon in the Total Annihilation / Spring community: the outcome of a multiplayer match is frequently considered to be set in stone after the result of the first raid. If you can cripple your opponent's economy early, you can set him back whilst your own vastly outstrips his. Cue large army smashing on your doorstep because your enemy was claiming metal spots whilst you were fending off raiders.
 * Homeworld lives by this trope. Don't harvest sufficient resources or maintain your fleet (through construction or capturing) and you will find later levels much more difficult. Do a good job and the later levels become much easier. In some of the later levels it helps if you deconstruct your fleet to some degree and quickly rebuild at the start of the level. The enemy force scales with yours but not your resources.
 * The RTS game Command & Conquer: Red Alert 2 was specifically rebalanced to avoid this, since the Red Alert had a rather bad problem with it. One of the developers described it as (something like) "winning a game in five minutes, then taking forty minutes to actually complete that victory."
 * In detail; in skirmishes, the computer would throw everything it has into its first attack, so if you can weather that you've beaten it.
 * Except that they haven't really improved it at all. On Medium difficulty, the AI focuses on camping and doesn't even bother attacking most of the time; on Brutal difficulty, they keep launching massed tank assaults until the map runs out of resources at which point they die if you so much as look at them funny. With superweapons turned off, the Red Alert 2 AI is a pushover in skirmish.
 * Towards the end of an early mission in Mech Commander you face a Mad Cat, a very tough enemy. The game does allow you to avoid the fight but beating it very often nets you this mech and with it you will waltz through the other early missions. The point being that only players good enough to get through the rest of the mission essentially unharmed can consider accepting battle, those struggling won't have their mechs in any shape to face it.
 * In the RTS game Seven Kingdoms 2: The Frythan Wars human factions must conscript new soldiers from their civilian population. A major loss can significantly drain the population of a player's cities as they try to replace their lost soldiers and hurt their economy. Made even worse is that soldiers level up, a lot. Soldiers in forts are constantly training and slowly gaining levels, and in battle gain several levels quickly. And finally every unit has an inventory where they can hold one unique item. A victor can walk away from a battle with an army that has gained several levels of experience and new items while the loser has to use his civilian population to create new rookie soldiers.
 * Additionally, the demonic frythan factions use life force gained from killing to create units. A victory for them can really boost their military might.
 * Dawn of War has it too. It doesn't matter how good your base defenses are, capturing strategic points/critical locations/relics is practically the only way to produce Requisition resource which is needed by absolutely everything. If someone gains an advantage here, they can Zerg Rush the losers who will never catch up in terms of production capabilities. The skirmish/multiplayer victory conditions Control Area and Take and Hold are specifically introduced to prevent this trope by ending the match whenever someone has gained critical advantage.
 * Master of Orion takes steps against the boring mop-up period, not against this trope itself. Every so often, the game's warring star empires convene and vote on unification. Anyone who's supported by two-thirds of the total galactic population wins the game.
 * Unfortunately the voting process is weighed against population; only the two most populated factions out of up to eight become candidates for the election, the vote of a faction is worth more as it grows on population, and the two candidates can, and will, vote for themselves. Its more of a mercy feature to prevent games to extend needlessly, as anyone who has the lead on the population race is often steamrolling in every field with little chance for anybody to catch up.
 * Some races, especially in Master of Orion II, have clear advantages over others, creating inherent imbalance. Playing as the Psilons, who get all advantages from researching a technology and a research boost (normally, a player has to pick one advantage per technology and trade for the rest), or the Elerians (who can see all star systems from the beginning and can conquer planets using mind-control) usually results in them curb-stomping everyone in short order.
 * Blizzard Entertainment RTS titles feature a fair amount of this trope, particularly in the first five or so minutes, where proper scouting, army composition, build order, supply-line harassment and Worker Unit saturation can easily decide the match. And then we start getting into Game Mods and things go Up to Eleven—remember, the Multiplayer Online Battle Arena genre originated as RTS mods, and in games like "Nexus Wars" (a Tower Defense variant), the opening minutes are both the slowest and the tensest.
 * In the Battle For Middle Earth series, hero units persist across campaign maps and the War of the Ring mode of Risk-style territory captures. By the time the Rise of the Witch expansion was produced, your armies were persistent in War of the Ring, thus letting you build up an army of elite upgraded top-tier units and simply roll across Middle Earth crushing everything in your way. Conversely, if a skilled enough player on the defensive could hold off the advance (often with the aid of fortifications like Helms Deep and copious amounts of archers), the player could not only completely shatter the offensive, but come out of it with a powerful army of the player's own and turn the game around.
 * In RHDE:
 * The more you expand your house, the more money you get to buy furniture. So if you don't expand your house much in early rounds, you can't catch up.
 * If the player fails to repair the walls of his house, all the furniture goes back into the player's inventory. It may take a couple rounds for a player to put back all the furniture, and the opponent may win two rounds in a row this way.

Rhythm Game

 * Many Rhythm Games reward players for hitting consecutive notes with point bonuses. As such, if you miss a note, you will need to rebuild your combo to get back the combo-based bonuses.
 * In Elite Beat Agents and Osu! Tatakae! Ouendan, your multiplier is equal to your current combo. This means if a song has a maximum combo of 300, and you miss on the first or last note, it means not a whole lot. But miss on the 150th note, and your score can really suffer because your point multiplier only went up to x150 instead of x299.
 * The BIT.TRIP series does this as well. Every beat successfully bounced/zapped/collected increases your base score per hit, and successfully hitting beats fills a meter that increases your score multiplier every time it becomes full. However, miss one beat (or fire a beam without hitting anything in CORE or touch a white beat in VOID) and your base score is reset, and missing too many beats fills a meter at the bottom that resets your multipler and sends you to a lower 'mode' where your scoring potential is reduced and you are closer to a game over. In CORE and VOID, this is taken even further in that there are modes that constantly increase your score and multiplier, but one miss causes a mode down and resets everything.
 * Gets egregious in later levels when shooting for a high score. Every tap you do starting from 2x combo will tack on (12-Easy/25-Normal/50-Harder) points to the values of every 300 you get. 100s, not so much. This results in FC's having almost double as many points as regular runs, and in that over 30% of your final can be from the last segment alone. By the end of Ep. 15, a single 300 can be worth as much as 30,000 points.
 * DJMAX attempts to strike a compromise: when you hit a note, you get a note judgment in the form of a percentage, and at the end of the song, the game averages your note percentages to produce your accuracy. Then there's the scoring system, which has the combo bonuses.
 * Similarly, Flash Flash Revoluion bases its point system off of both hitting notes properly, and the highest level your combo reaches on the song. Thus, it's often in your best interest to mash buttons in time with the music if you lose the rhythm of the song, as the points gained from keeping your combo up will negate the points lost by hitting buttons when you shouldn't.
 * In Guitar Hero and Rock Band (before Rock Band 3, which allows saving with no-fail on), nailing a star section gives you star power, which you can deploy on demand to make it easier to keep your health up. If you miss the star sections, you won't have the star power to BS your way through the tricky stuff.

Role-Playing Game

 * World Tendency in Demon's Souls works this way. If you die while in Body Form, World Tendency shifts towards black. On the contrary, if you defeat a boss or certain black phantoms that only appear in Pure Black World Tendency, it shifts towards white. As it gets whiter, the enemies are easier to kill and do less damage. As it gets blacker, the enemies are more difficult. However, in Black World Tendency, the item drops are much more valuable.
 * Final Fantasy Tactics A2 has this for the auction houses. At first, you barely stand a chance at winning since you only have a handful of 1, 2, and 3 point tokens, but if you play several times to unlock the ability to buy tokens before starting the auction, then the whole thing becomes piss easy. It can also lead to a Game Breaker or Disc One Nuke if you get this ability early and use it to sweep the board to win powerful items.
 * Final Fantasy X with its Overkill mechanic can cause a positive-feedback loop; higher-level characters will score overkills more often, getting more experience and keeping them higher-level to score more overkills...
 * In the Fire Emblem series it's near inverted, as although the more units on your side the better, if you try to level each unit equally, you'll be left with not very good units and be overwhelmed easily.
 * Also, if you spend the limited amount of gold you're given too quickly or hold on until the last moment, you'll end up with not very good gear besides the special equipment that you're given.
 * While too many units is a problem, so is not enough. If a crucial or powerful unit is defeated and you're short on people, then unless you do a Ass Pull, you're finished anyway.

Shoot'Em Up

 * Your maximum power in most Gradius games: missiles, a laser attack (or double shot), four Options, and a shield. This takes 31 or 32 powerup capsules. On dying, you lose all of this.
 * Blazing Lasers is a good example of the space shooter power-up problem. The weapons level up seven times. The later levels are tough enough with the best weapons. If you die once, it's virtually impossible to build them back up without dying again.
 * Star Soldier (the Wii Ware one, probably other ones) rubs Unstable Equilibrium in the face of gamers everywhere with an (admittedly generous) twist on the "die and lose all your weapons" concept. Your weapon strength is tied to your health, so each time you're hit, your weapons get weaker and weaker until you die. The short "score attack" nature of the Wii Ware game makes this a bit easier to swallow.
 * In most games in the Darius series, dying can decrease your firepower by a lot.
 * In the original Darius, powering up your weapon, bomb, or shield 6 times will upgrade it, and on dying, you lose all of your powerups. So you could be on the last powerup level for your missile shot (red triple missiles), ready to get another powerup so you can get the laser, but when you die, you downgrade all the way back to green single missile.
 * Darius II decides to just say "fuck you" and take away all of your powerups.
 * Darius Gaiden takes away two shot levels every time you die. Depending on how many extra lives you've built up, consecutive deaths could whittle you all the way from the awesome wave shots to the lowly missile shots. And because this game is Nintendo Hard, if you get downgraded like this in the last few stages, you might as well kill off your remaining lives because the rest of the game is now near-impossible to clear.
 * The arcade game Twin Eagle: Revenge Joe's Brother was rather unfair with this trope, for example you get plenty of weapon powerups in the first level, but hardly any in the second. It also features cheap Dynamic Difficulty, ie the further you play without dying, the more likely you are to die and lose your powerups.
 * Twin Cobra does this too, exacerbated by power-ups being fewer and farther between in later levels.
 * In Thunder Force III and its sequels, dying will, instead of taking away every weapon (besides the two that you start with), take away only the weapon you were using. This leads to situations where, in order to keep a particularly useful weapon and you are in a very risky situation, you have to not use that weapon. So much for using Free Range and Sever on those more difficult bosses!
 * Shoot Em Ups that penalize more for bombing than dying, resulting in games that end sooner with plenty of bombs left having higher scores than games that are completed and have lots of bombs used up. Some offenders:
 * Every mode in Mushihime-sama Futari Black Label—lose one life and your counter drops by about 1,000-2,000. Use a bomb, and your counter drops by at least 6,000.
 * A couple of the later games in the Touhou series have some such irritating game mechanics:
 * Both Mountain of Faith and Subterranean Animism have a shot power penalty for bombing, so if you bomb against a boss, its attacks will last longer, which means you're more likely to have to use another bomb. MoF does grant one "free" bomb at full power, since the shot power is exactly the same from 4.00 through the max of 5.00, but drop to 2 or less during a boss fight and you're pretty much screwed.
 * Mountain of Faith also has the Faith Point system, which determines the score value of the blue point items. Each time you die, your total Faith Points take a permanent hit, making every single blue point item for the rest of the run worth fewer points. Meanwhile, extra lives are awarded based on score.
 * In Subterranean Animism, bosses can drop a life fragment item after every attack phase, and an extra life is awarded for every 5 life fragments collected. The problem? If you die during the attack phase, the boss won't drop the life fragment at the end of that attack phase. In addition, if you don't finish the attack phase within the time limit, the boss also will fail to drop a life fragment, while the power loss from bombing makes it more likely that time will run out.
 * In Undefined Fantastic Object and Ten Desires dying reduces your power by 1.00. Out of 4.00. While the games are quite generous with power items during stages, they're much harder to come by during boss fights. So if you die during (or just before) a boss fight you're going to have to finish the fight with about 25% less firepower than you'd have otherwise, making all the patterns take longer, making you more likely to die.
 * In Legendary Wings, your weapon power acts as your health, everytime you get hit your power decreases, until you die.
 * In Terra Cresta, your attack drones can be destroyed by enemy fire, making you more likely to lose another, repeat until death.
 * In Axelay, your currently-equipped weapon gets disabled when you get hit, if it doesn't kill you outright.
 * Border Down has a unique take on this. There are three colored borders in the game: green, yellow, and red, which you choose one of at the start of the game and may or may not be able to manually change between stages depending on how high you scored in the previous stage. Each border is a different variation of a stage: green border is the easiest, while red is the hardest. They also represent your lives remaining: getting hit in green demotes you to yellow border, getting hit in yellow demotes you to red, and getting hit in red results in a Game Over.
 * The very first Raiden had this. At full power, you can have a vulcan cannon that covers almost 180 degrees in front of you as well as huge dumbfire missiles (and/or a Wave Motion Gun and stupidly fast homing missiles). Die, and you're back to a basic two-bullet shot with no sub-weapon. It takes 2-3 stages of powerups to get up to max.
 * The sequel and DX fixed it a bit with fairies, which would spawn if you die and give you some powerups so you didn't lose absolutely everything. The Raiden Fighters series is much more generous with powerups so it isn't much of a problem at all.
 * Heavy Weapon had this with your Smart Bombs. In most shooters, you are restocked with a certain number of bombs after death. In Heavy Weapon, you lose all your Nukes on death! This makes the waves even harder as you now don't have the ability to clear the screen of enemies and bullets.
 * In Thwaite, after a missile silo is blown up, it's out of commission for the remainder of that round and until either sunrise or the player completes a round without a single building being destroyed. At this point, the player has fewer missiles to work with, and one strategy is to ignore half the buildings.

Stealth Based Game

 * The first two games in the Thief series had an interesting way to deal with this: The loot you steal on your last mission is used to purchase weapons and upgrades for your next one, however any unspent gold is lost and the stuff you buy does not carry over to following missions, so there's no point in hoarding it. You always have to buy your entire loadout (except for a few default items) using only the gold you collected on the previous level. Deadly Shadows did away with this.

Third-Person Shooter

 * In the Star Wars Battlefront series, a team who holds the majority of command posts will cause the other team's reserves to start dropping, thus creating an incentive to keep grabbing command posts instead of spawn camping and ending the game faster if one side gains a significant territorial advantage. This also occurs if one side destroys an important objective (Hoth's power generator, Endor's shield bunker).
 * In the sequel, the game host can choose whether hero/villain characters are given to good players as a reward or to bad players to give them a a chance.

Turn-Based Strategy

 * In more turn-based games, giving a player an extra turn for doing well (extra turn for throwing a six in a simple board game, for example) can cause this via too much positive feedback. Snooker offers an excellent examples of this; it not being too uncommon for fairly evenly matched frames between world-championship-level players to have frames won by over 70 points... let's just say the final of the World Championship is played as a best-of-35 for a reason.
 * The PSP game Jeanne D'Arc would have the same problem, were multiplayer available: when the title character is in Limit Break, killing an enemy gives her another turn. It's not all that hard to set up the battlefield for her to leapfrog around one-shotting everyone.
 * The newest Valkyrie Profile game, Covenant of the Plume, uses overkill damage to determine what rewards you get from Mistress Hel after each battle. Score a lot of overkill damage? You get extremely nice stuff, such as powerful weapons or in a certain route, an item that actually increases the maximum amount of Sin you can get from each enemy from 100 to 120. Score an insufficient amount? Good luck with the Realmstalkers, Hel's servants that almost force you to use the Plume just to get rid of them. Given that usage of the Plume automatically gets you closer to getting owned by Freya and/or the bad ending, but nets you enough points to outright ignore the overkill situation, it's probably her way of saying "you moron, you want to kill Lenneth or not? Don't fuck up."
 * In Battle for Wesnoth, every unit has a name, a level, and experience points. Units from previous levels can be "recalled" in subsequent ones, and this is pretty much the only way to succeed. The computer, on the other hand, can recruit preprogrammed loadouts of pre-leveled units by the bucketload. This tends to make things difficult if too many units die or you fail to soak up enough experience points early in the campaign.
 * Paradox Interactive's Hearts of Iron II avoids the problem of conquering empire becoming too powerful to defeat in a few ways:
 * 1) Whenever you officially annex a country, instead of receiving all of its I Cs (Industrial Credits, the units of production in the game) instead you receive only 20%.
 * 2) Recently conquered territories will usually not like being under your rule, and you will have to garrison a number of divisions of troops to prevent partisans from rising up against you.
 * 3) Supply lines are somewhat used in the game. If your troops advance too quickly across territory, their supply lines might become strained, which will reduce their ability to defend your territory.
 * The same company's Europa Universalis series also tries to avert this with its "Stability" mechanic: Every country has a Stability rating that fluctuates many times during the game, often being lowered by certain events. Stability affects both revolt risk and tax income. Where this trope comes in is that each province a faction holds adds a little extra to the cost of raising its Stability (though a nation's "core" provinces have much lower costs); an empire holding a large number of low-income, non-core provinces might actually cost more to keep stable than it's worth.
 * German strategy game Battle Isle has a predefined deployment of troops on the map of every scenario of the campaign, however, these units can carry over their experience from previous mission. So it comes with a huge advantage to take care of your units. Battle Isle III even had an extra mission that deployed your units in such a fashion that you can't save all of them, diminishing the effects of this trope for the following final missions a little.
 * In general, any turn-based strategy game that has persistent armies, unit dieoff, and no upkeep cost for maintaining old units will at the very least not inconvenience you for keeping old troops alive. In many cases, the game is balanced for a certain rate of dieoff, and going below that rate will make your army more effective, allowing you to avoid dieoff even further. (Heroes of Might and Magic is a good series to see this in action—it's possible to beat many scenarios in the fourth game without ever losing a unit.)
 * Similarly, any strategy game that allows you to train powerful persistent hero units, especially across maps in a campaign, can lead to snowballing situations where your high-level heroes can take on entire enemy armies by themselves at the start of the map, plowing through any resistance and allowing you to secure an overwhelming advantage against your enemies. In the fourth game of Heroes of Might and Magic, lingering on maps to ensure that you get the maximum amount of experience, spells, upgrades, and equipment is a surefire way to turn your persistent hero into a One-Man Army. Age of Wonders has a similar campaign system.

Turn Based Tactics

 * X-COM uses this very hard. If you do well at the start, you'll have more money and therefore can hire more scientists, getting you better technology, improving your odds in battles, etc. This results in the game being very hard at the start but ridiculously easy toward the end. This is partially accounted for by more powerful aliens sequentially appearing throughout the game, and them being better armed, but not sufficiently to make the game's difficulty smooth. Many self imposed challenges have originated from this.

Racing Game

 * In Mario Kart grand prix, winning a race means you start the next race slightly ahead of everyone else; the players start in the order they finished the previous race.
 * The developers restored equilibrium to the formula by giving players more chances to get powerful items to gain positions (such as Red Shells or Stars) when they are in lower positions, and making some of them less effective if you don't have much of a disadvantage (the Magnum Bill, for example, lasts much longer if you use it from the 12th position rather than from the 5th).

Literature

 * The Lone Wolf gamebooks reward you for playing through all the adventures by allowing you to add an extra Discipline for each previous adventure you completed. By and large, these make life easier but don't give you a massive advantage. Until Grand Master. In addition to the Discipline benefits, you gain 1 Combat Skill point and 2 Endurance points for each adventure completed. The upshot is that the adventures actually get easier as you go, to the point where the ultimate mission...going alone into the evil god's universe and swiping a legendary artifact from his inner sanctum...is an absolute cakewalk.
 * Though this gets inverted in some of the later books, where having some of the items you get from previous books, most notably the Sommerswerd, will make some bosses exponentially harder, to the point where one boss is mathematically imposable unless you have a very specific set of disciplines, have gotten and saved every single stat boosting item you can get by that point in the game, have both of END and CS scores maxed, AND gotten a one of a kind potion in the third book that boosts your combat score higher then any other potion in the game and refrained from losing/using it until the boss battle, in the eleventh book. Even then it requires a lot of luck with the combat rolls.
 * It's notable that there are several fanon attempts to explain why it would be perfectly logical for Lone Wolf to NOT bring the only non-evil weapon in the world able to kill the Big Bad's with him when he invades one on there strongholds, just to make that fight easier.
 * "For everyone who has will be given more, and he will have an abundance. Whoever does not have, even what he has will be taken from him."
 * "He cuts off every branch in me that bears no fruit, while every branch that does bear fruit he prunes so that it will be even more fruitful."

Tabletop Games

 * Blood Bowl had so much of a problem with this that most of the changes in the fourth edition were intended to fix it. They actually managed to do the exact opposite, and the so-called Living Rulebook was created to fix that damage. Nowadays Blood Bowl is more boring but also more balanced.
 * Many Tabletop Games give injured characters penalties to their ability to keep fighting, which of course tends to result in rapidly decreasing odds of winning the fight. This is commonly called "Death Spiral", and whether it's a good or bad thing is a common cause of argument.
 * More specifically, Sanity in Call of Cthulhu (tabletop game). When you fail a roll, your Sanity decreases, making it easier to fail rolls, although this is meant to represent the descent into madness.
 * Dungeons & Dragons doesn't have special rules or cases to enforce this, but like any resource management game it can be a concern. In earlier editions, having one or two of your big spells fizzle can make your Wizard a walking liability (especially at early levels, before you have a few dozen spell levels worth of backup fodder). In 4th Edition, the designers realized just how devastating it could be to a party's resource structure to miss with a Daily power, and so made most Dailies still have some effect on a miss (or, in the case of Reliable powers, not be expended until they hit.) Essentially, most fights of average size last between three and five rounds, and missing out on a round's worth of actions for any reason can reduce your combat effectiveness by 30% or more. In a big setpiece fight with a solo monster you're Damage Racing, getting stunned or missing with your best shot can make all the difference.
 * Risk is a mixed bag. As players conquer more territory, they get exponentially more troops. This means that the guy to conquer the most gets the most troops. However, this is to counterbalance the side effect of spreading your troops too thin.
 * And of course, there's the human factor...
 * Chess has very strong elements of this. A player who gets behind in the opening development will have a very hard time catching up with his opponent. In a similar way, if one player manages to get a material advantage ("material" as in "combined value of all pieces"), that player will likely be able to exploit and increase said advantage.
 * Poker. While you get the same (random) cards whether you're down or up, a short-stacked player can't thicken the pot as well when he has really strong hands, and can't use the threat of a large raise to force players out and protect his "drawing" hands.
 * In the obscure Digimon TCG, only the winning side could Digivolve, making his character stronger. This basically meant that whoever was winning after the first turn was going to win, hands-down.
 * A Magic: The Gathering player that can decimate his opponent's forces has a few rounds of easy pain-causing before the other side can bring itself up to speed. The solution is often one of the "Wrath of God" cards that clean the whole board and re-equalize the situation.
 * The concept of Tempo also highlights this - well-timed spells and abilities can be used to slowly gain total control over the flow of the game through card advantage, denial of critical spells, or even just by delaying the opponent, so a player who can snipe out critical spells or permanents can effectively cripple an opponent so badly, only the most unexpected spells or the worst possible draws can ruin their advantage. Of course, tempo can swing both ways, as a canny Aggro player can lure out a Wrath of God with a token army, then summon the real threat after making the opponent use up their mana and spells to stop that feint.
 * This is part of the archetypal Green Ramp deck. Play cards that give extra mana, use the extra mana to get more mana, repeat until you can drop enormously expensive things early in the game.
 * The World Wrestling Entertainment TCG Raw Deal had probably the most extreme example of this. The game had no mana; instead, you could play cards with a Fortitude "cost" equal to or less than the amount of Damage you'd already played. In other words, the more damage you've dealt, the more damage you can deal. They addressed this with powerful cards in the next expansion that only worked if you were behind ... which then made it more advantageous to be behind ... which was addressed with powerful cards that only worked if you were ahead in the following expansion ... and the cycle of life continues.
 * In the Pokémon Trading Card Game, the player who knocks out a Pokémon gets to draw an extra card, which is a small but significant edge. The player whose Pokémon gets knocked out must discard any cards attached to it, which nearly every Pokémon requires in order to attack and may have needed several turns to build up, a substantial setback. Quite often, there has not been time to attach anything to any Pokémon but the one attacking, meaning the player whose Pokémon has just been knocked out must start all over while the other player still has all of the necessary attachments.

Real Life

 * In the U.S. and U.K., there is a correlation between which part of the year a person is born in and their success in school and/or sports. The theoretical reason for this is that, in the early grades, the oldest children in a grade will be physically and mentally more developed than the youngest. This allows them to understand and retain more information/ get more practice, while the youngest are dragged down by an early poor performance. Subsequently, the older children start the next school year with an even bigger head start. The advantage stacks year by year.
 * To counteract this phenomenon (or perhaps to take advantage of it), some parents purposely delay enrolling their children in preschool or kindergarten for a year. This is referred to by some researchers as red-shirting, which seems to have mixed effects.
 * This is thoroughly explored in Malcolm Gladwell's Outliers, most effectively early on with respect to the Canadian junior hockey league, in which most of the players are born early in the year, with birthdays later in the year becoming vanishingly rare. This is because the league is yearly, and at the earliest ages a difference of a few months makes a big difference in coordination. By age 17, that advantage is gone and has been replaced by years of being given more and better training. School systems that avoid differentiating children until later ages don't see the same birthday gaps as those that differentiate earlier. The rest of the book is less well supported, but still compelling.
 * It would be interesting to see this effect explored in sports where increased age is a disadvantage, such as gymnastics and figure skating. For elite-track gymnasts, the age race may be so profound that parents and coaches deliberately seek out children with later birthdays - for example, much has been made of the fact that Gabrielle Douglas, member of the USA Women's Artistic Gymnastics team, has a December 31 birthday. Thus she will be eligible for the 2012 Olympics while she is 15 years and 9 months old, compared to competitors who mostly range from 16 to 18.
 * Impoverished communities get a bad reputation in the news for criminal activity related to poverty. Businesses and people don't invest there, increasing poverty, and kids there get the idea that crime is "the norm" (even if the vast majority of people living there are not criminals), increasing crime.
 * "The rich get richer, the poor get poorer". To grossly oversimplify, the rich can afford to take spare cash and invest it, gaining more cash. This cash can then be invested for even more cash. The poor struggle to meet their daily necessities - or, for the worst off, do not even succeed in doing so - and, barring external aid, remain poor forever. Even when they get external aid, the most common form is through a loan. If they can't capitalize on the loan well enough, they'll have to pay out debt on top of everything else. Laws can be created to stabilize this, but take a wild guess at what you need to get laws passed.
 * Explored further in this Cracked article.
 * America's Republican and Democratic primaries. Winning in early states like Iowa and New Hampshire enhances a candidate's stature, even if they don't actually provide very many delegates, and makes them more likely to win other states down the road. Because of this, candidates will spend immense amounts of time campaigning in Iowa and New Hampshire even though they're fairly small states.
 * Predatory pricing runs on this. Big, rich companies deliberately lower their prices to what their smaller competitors cannot match, taking a temporary loss of revenue that they can afford. The smaller companies can lose business now by refusing to lower their prices or lower their prices now and make losses that kill them later. The big company then swoops in on the market share they leave behind.
 * Fighting. Being hit hurts, and makes your body slow down in order to avoid hurting itself more. Which makes you easier to hit. Which, as previously mentioned, hurts.
 * The creation of the universe followed this trope. During the big bang, a huge amount of matter and a huge amount of antimatter was created at once. But there was a tiny amount more matter than antimatter. The matter and antimatter annihilated each other, leaving just a fraction of the original amount created - which then went on to form the stars and galaxies we see today.