An often controversial element of gameplay that unexpectedly trumps all others, a Game-Breaker is an element of a game that, due to underestimated abilities (whether on its own or when it's combined with another item/mechanic) or players coming up with creative ways of using it, ends up making the game hugely easy.

For example, in a game where the player's capabilities are meant to be limited by their access to currency, an easy trick that reaps a lot of money for little effort can become a Game-Breaker. Or a particular gun having extreme firepower, high accuracy, and a high ammo capacity; or a Fighting Game character having a fast, unblockable move with very high priority (the ally equivalent to the SNK Boss). In games with a choice of playable characters, one may be much easier than the others and allow for skipping parts of levels that other characters would have to wade through slowly.

Developers might add a Necessary Drawback to weapons or powers, but due to an oversight this drawback might never enter into action (for example, if the counter is easily neutered by other means). Then it is easy to get a game breaking ability.

Another example is the potentially convoluted win/make-then-sell exploit, which is common in games with customizable items. A borderline example may be the trick of saving your game before a random item appears and reloading until you get the particular item you want, also known as Save Scumming.

A Game-Breaker can boost a pre-existing strategy or character and make it overwhelmingly powerful against things it would normally be balanced against — Scissors crushing Rock, so to speak. One fan term for it is "cheesing". Depending upon who you ask, it may or may not be considered cheating. The Meta Game ends up revolving around who can get the Game-Breaker (or use it on the other) first, resulting in Gameplay Derailment.

Patches will often seek to rectify this. However, this often leads to an outcry among players who favored the original tactic. Worse, sometimes the nerfing of one Game-Breaker results in another Game-Breaker being discovered as a result, prompting the developers to consider whether they should apply a patch for the second one, or undo the previous patch, so the two Game-Breakers will balance each other out as they used to.

Game-Breakers are often controversial and subjective. Rarely do people actually agree on what is and is not game-breaking. Heated debates (or worse) over Game-Breakers spread like wildfire on the Internet, or even around the house. It's obvious that the extremes of the Munchkin or the Scrub are wrong. However, there are techniques whose power is hard or even impossible to call.

Banning glitches and "unintentional" moves is usually a difficult thing to do. Sometimes it can be hard to tell whether something is a glitch or not, sometimes a glitch happens so often that you'd have to go out of your way to have it not happen, and other times it can be argued that a glitch adds more depth to a game rather than less.

The upshot is that you should probably take most of the below examples of multiplayer games with a kilo of salt. (No, not that kind of salt.)

Unlike video games, many older Tabletop RPGs have a built-in check in the form of the Game Master, who can override published rules for the sake of everyone's enjoyment; thus, with a good Game Master, no Game-Breaker is possible. However, this naturally carries the corollary that, with a bad Game Master, the game comes pre-broken. Just what is and isn't game-breaking is, again, controversial, and many GMs have to deal with a limited player base; too heavy or too light a hand may alienate players and destroy the Game Master's plan.

Compare Disc-One Nuke and Sequence Breaking. A Lethal Joke Character may be one of these, as will the One-Man Party if the game's balance is easily skewed. Lightning Bruisers are also common candidates. Some Boring, but Practical moves/tactics may border on this. That One Attack, when available un-nerfed to players, usually becomes this, as will any particularly powerful Min Maxers Delight. The Obvious Rule Patch is typically a response (but not necessarily a typical response) to the presence of this trope. Contrast The Computer Is a Cheating Bastard, as well as Skill Gate Characters that appear this way to newbies but can be taken apart by experts. Difficult, but Awesome characters can also be this when they're so overwhelmingly powerful when mastered that there's no way to beat a skilled user. Often overlaps with High-Tier Scrappy. Often the cause of Complacent Gaming Syndrome.

Oftentimes, your average Cheese Strategy will use this to grand effect, particularly if the game-breaking aspect of it is something that even the least-skilled or least-knowledgeable player would still be able to figure out, but just because something is a Cheese Strategy doesn't make it a game-breaker, nor vice-versa. Only if it is a truly-unbalanced mechanic would they intersect.

A power-up that would be a Game-Breaker, except that it only appears when the game is essentially over, is Purposely Overpowered — note that most examples of these tend to be single-player affairs, where there are no other opponents to become offended over it. For stats that, once boosted to a high enough degree, make the character into a Game-Breaker, see One Stat to Rule Them All.

Note that this is not another word for 'overpowered'. To be a true Game-Breaker, the ability or character in question must be so hideously unbalanced that it makes people just quit the game in disgust. It's so powerful that there are only two kinds of people: the ones that use it, and the ones that lose to it. That's why people quit in disgust: it destroys all semblance of choice, and quite possibly all semblance of fun. Your available tactics are now limited to one—the one that works. And what if you don't like that tactic? What if it's a gun in a game where you prefer swordplay? What if it involves Attack! Attack! Attack! when you're more of a defensive turtler? What if it requires you to play the Mighty Glacier, but you're a Fragile Speedster player? Well, then, it sucks to be you. You can play the game the way you want to, and lose... or you can follow the crowd, and maybe win. Small wonder some players Take a Third Option and Rage Quit instead.

Not to be confused with Game-Breaking Bug, for when you can literally "break" the game by crashing the underlying software or leaving your saved game in an Unwinnable state, or Game Changer. The narrative equivalent of this trope is Story-Breaker Power.

Examples:

• Action
• Adventure Game
• Card Battle Game
• Fighting Games
• First-Person Shooter
• Massively Multiplayer Online Games
• Platform
• Puzzle
• Racing
• Real-Time Strategy
• Rhythm Games
• Role Playing
• Shoot 'em Ups
• Simulation
• Sports Games
• Survival Horror
• Tabletop Games
• Tabletop RPG
• Third-Person Shooter
• Tower Defense
• Turn-Based Strategy
• Wide-Open Sandbox
• Game Show
• Other Games