House Rules

The rules of any given tabletop game do not have to be limited to what is listed in the rulebook.

The rules of Monopoly are good and fun. But really, the auction rules are lame, Free Parking needs something to make it more exciting, and shouldn't you be able to travel on railroads you own?

Welcome to House Rules. Any rule that players add to or change in a standardized game is a house rule, named after the varying rules used in casinos (where you bet against "the house"). House Rules are, in a way, the Fan Fiction of Board Games and Tabletop RPGs.

The Game Master can inflict his House Rules on the gaming group whether they want him to or not. This can be a recipe for social disaster if done poorly, or a welcomed improvement. In fact, some table top games encourage House Rules, and offer advice for how to make them fit with the rest of the game. However, attempting to impose your rules on the rest of the world may get you labeled as a Scrub or as the Stop Having Fun Guy, depending on the tone you use.

House Rules are not the same as errata, which are released by the publisher and are used nearly everywhere that knows about them. Errata are small corrections, or updates that the developers made before the game was officially published, but after the game has gone to print and can't be altered, while 'house rules' often fall under the category of 'whatever's convenient', either for gameplay reasons or to fix a broken aspect of the game system. Deliberately ignoring the errata, however, would be an example of house rules. Sometimes they can end up canon when former players start making the game.

Please note that while House does, in fact, rule, this is entirely unrelated. Also is not directly related to (but may be used to tweak) a House System. Not to be confused with the book House Rules, which is about a murder trial involving an eighteen-year-old with Asperger's Syndrome.

For the video game equivalents, see Self-Imposed Challenge (undertaken within the mechanics of the game) and Game Mod (altering those mechanics themselves). See Variant Chess for a fiction-based trope with narrative uses.

Anime and Manga

 * Yu-Gi-Oh!: In an anime so dependent on a card game, it makes sense that this Trope would show up a lot:
 * In a way, every Tournament Arc (including Duelist Kingdom, Battle City, Genex Tournament, and so on) have House Rules, as their rules are very different than actual tournaments. The rules are more like a Battle Royale, where any participating duelist can challenge any other. Winning means gaining some sort of Plot Coupon (like Star Chips in Duelist Kingdom) and getting enough of them grants access to the finals, which at that point, it becomes more like a true elimination-style tournament.
 * Duelist Kingdom in the original anime had special rule that was not immediately obvious to most of the contestants. Certain monsters gained a “field power bonus” to their Scores depending on where they dueled on the island. For example, Insects and Beasts gained the bonus in forested areas, Warriors gained it in grasslands, Fish and Aqua monsters gained it on the shore, and so on. Unfortunately, Pegasus showed a little favoritism, giving a sneak preview of the rules to some tournament winners - including Weevil, who used this knowledge to lure Yugi to the forest where - he thought - he’d have advantage.
 * In that same arc, there was the Labyrinth Duel, which sort of combined Duel Monsters with a board game. The playing field was a maze-like arena on a grid, and each monster could move one square per turn for each Level it had. (For instance, Yugi’s Celtic Guardian could move four squares per turn, while his Dark Magician could move seven.) Monsters could only fight each other when they occupied the same space. The manga actually listed official rules for this format, but it never caught on.
 * The original version of Kaiba's Duel Disk was pretty much a reformatting of the entire game, and was designed to give him an advantage over Pegasus. During the draw phase, a player would always draw until his hand consisted of 5 cards (and he had to skip it if he already had five); only one monster could be on the field at the time, but the player could attack the cards comprising his opponent's hand. Monster Cards attacked this way were considered to be in Attack Mode, but if a Spell or Trap was attacked, it was destroyed automatically with no damage to either player.
 * In the Virtual Nightmare Arc of the original series, Noah implemented the Deckmaster system for duels; in this system, each player chooses one monster from his deck; said monster acts as a sort of corner-man for the duelist, and has an effect that is unique for each monster; the Deckmaster can be summoned, but if it is destroyed, the owner loses automatically. Noah invented this system mostly due to his desire to prove himself superior to Seto Kaiba; the idea was to improve upon Seto's favorite game. Despite Kaiba’s insistence that they never talk of it again, Deckmasters are very popular with fanfic writers, and inspired a similar system in Duelists of the Roses.
 * The special rules for Turbo Duels in Yu-Gi-Oh! 5D's (which involve the "Speed World" Field Spell which prevents the use of all Spell Cards except "Speed Spells", where the number of "Speed Counters" you have determines how powerful a Spell Card you can use) can also be considered House Rules.
 * In Yu-Gi-Oh! ARC-V, there are Action Duels, which are a combination of Duel Monsters and performing arts. The rules are complex, and a summary is found here.
 * ARC-V also Introduced something called the “Intrusion Penalty” for the Tournament Arc. This stated that a duelist could join a duel in progress (either to help either side or oppose both) but if so, the “intruding” duelist started with 2,000 LP rather than 4,000. Sadly, this “penalty” quickly became redundant; aside from the first time it was seen onscreen, a duelist penalized for it (usually a member of the main cast) would win on his first turn.
 * Speed Duels in Yu-Gi-Oh! VRAINS is similar to the duels used in Duel Terminal and Duel Links. In the anime, these duels are done via virtual reality in cyberspace. Hand size is limited to four, and there is no Main Phase 2. Also, each duelist has a Skill he and she can use once per duel, similar to the Deckmaster system.

Board Games

 * The above mentioned Monopoly has a plethora of house rules that have been played. Here's some of the most popular over the years.
 * Putting various fines (mainly taxes) which, by strict rules, would go to the bank in the center of the board and giving all the money to whoever just landed on "Free Parking" is very popular. It's not part of the general rules because, in the endgame, a random landing on Free Parking may prevent a poor player from going bankrupt for several more turns, extending the game when it is already starting to get tiresome.
 * This is actually a rule in Monopoly Junior (set at a funfair), where Free Parking becomes "Uncle Pennybags' Loose Change," and the money comes from a couple of rides and the restrooms.
 * "Double Money for Landing on GO". Some sticklers will argue that it doesn't apply to cards that say "Go directly to GO" because they state specifically "Collect 200 dollars". Opposing sticklers will argue saying that they should get the 400 in addition to the extra 200 because it doesn't directly state the 200 dollars come from GO. This is how friendships are destroyed, families are broken and lives are lost.
 * Another fun house rule: Official Monopoly rules require any purchasable property that is not immediately purchased by the person who landed on it to be auctioned. A house rule is to leave such a property unowned (and not charging rent) until someone who is ready to purchase it lands on it. This rule can allow more expensive properties to go unowned until near the endgame.
 * This rule normally exists because either people can't be arsed with auctions, or there will be one wag who sets a new world record for the fastest person to say "OnepoundgoingoncegoingtwiceSOLDMINE".
 * More serious gamers, who usually turn their noses up at Monopoly, might find it more interesting with the inverse rule: any unowned property that is landed on immediately goes to auction, i.e., the person who landed on it does not get the option to buy it at face value first.
 * Referenced by Victoria Wood in a monologue about spending Christmas with a friend's family. Never play Monopoly with people who've been playing it together for decades, because everything you do will be wrong.
 * That rule is the very point of the game called Monopoly ...
 * "No buying property on the first lap" is another very common one, intended to balance out the advantage gained by going first. Bad luck with the "Go To Jail" square can completely break this game, though.
 * It's worth noting that most Monopoly house rules break game balance and are the leading cause of the hours-long sessions that result in family members not speaking to each other for years.
 * Another set of house rules is that you can develop each property monopoly freely as you see fit.
 * The ability to merge into alliances and trusts is a very common house rule.
 * In the Finnish classic board game Star of Africa it was possible to have a situation where nobody can win the game. After more than 50 years of various house rules to prevent this, a re-release finally fixed this.
 * The rules of Tigris & Euphrates say that in an external red conflict, temples with leaders next to them aren't removed. But really, isn't that a bit lame? The obvious alternative, however, that they're all removed, is simply too powerful. One compromise is to remove as many temples as possible in such a way that each leader still has at least one temple next to him.
 * Mahjong, especially the Japanese variant, has many house rules. Common house rules include:
 * Yakuman stacking: A few very special hand types (known as yakuman) are automatically worth the Cap of 32,000 points (subject to the x1.5 multiplier if the player who is holding the dealer button wins, for 48,000 total). On the even rarer occasion that someone completes a hand which fulfills more than one yakuman condition, this rule allows them to win 32,000 points per yakuman condition the hand fulfills. This makes it possible, albeit extremely improbable (the odds are better of winning the lottery twice in the same month), to form a hand worth 336,000 points.
 * Wareme: When someone wins a hand, whoever is sitting behind the broken tile wall (i.e. the wall where the initial draw started) wins and loses double.
 * Doukasen: When someone wins a hand, whoever is sitting behind the tile wall the last tile was drawn from wins and loses double.
 * Open Riichi: Upon declaration of Riichi, a player can reveal his/her entire hand (or just the portion that's relevant to what he/she needs as the last tile to win), so that opponents can figure out what he/she needs to win and avoid discarding those tile(s). 1 extra han (hand point) for winning the hand after doing so. An additional house sub-rule can make it worth a yakuman (the Cap of 13 han, converts to 32,000 Scoring Points) if the Open Riichi player gets the last tile from someone else's discard, and the losing player could have legally discarded a different tile that wouldn't have let the winner win from his/her discard.
 * Kuitan Nashi: The Tanyao yaku only counts if the hand is closed (formed without called discards). This is an Obvious Rule Patch to prevent players from calling tiles left and right to try and finish their hand with Tanyao to fulfill the 1-yaku requirement just to claim bonus points for dora.
 * Aotenjou ("Skyrocketing"): The exponential score formula that's normally used for hands worth less than 8,000 points is used for all hands, without the 8,000-point soft Cap. This means, for example, that a hand with 13 or more han is worth over 2 million points at a bare minimum, instead of the usual 32,000 hard cap.
 * Usually there is also a separate rule on how to handle yakuman (see "Yakuman stacking" above). In the Touhou fangame Touhou Unreal Mahjong, the Aotenjou mode yakuman rule is "yakuman are worth 13 han, and multiple yakuman stack multiplicatively". This makes it possible to create a hand worth over 4 billion points.
 * The latest installment of the Mahjong Fight Club arcade series also adds a mode which uses one of several creative house rules (with which house rule being used rotating depending on the date). Some of the house rules include:
 * Each player can see the entire hand of the player on his/her left.
 * Each player can see what he/she will draw on his/her next turn assuming nobody takes another player's discard (which shifts the order).
 * Each player's starting hand is visible to everyone and those tiles remain visible for the hand; only drawn tiles are concealed.
 * Each player starts with only 13,000 points, making it much easier to bankrupt a player. Busting another player yields a bonus, deducted from the busted player(s).
 * Each player is timed on how long he/she takes for each turn. At the end of the match, an additional rank bonus is given to the player with the fastest average time per turn, deducted from the player with the slowest average time.

Card Games

 * The game "One Thousand Blank White Cards" is almost nothing but house rules; it's part of what makes it fun. To clarify, it's played like this: each player receives a hand of completely blank cards (five or seven, usually). At any time, a player may take a blank card and write its rules on it (along with drawing a picture of stick figures). Once a card has been written on, it can be played, and the rules written on it take effect. The house rule "no cards that allow one player to win instantly" is usually declared up front.
 * All the manner of alternate cooperative dueling rules exist for Magic: The Gathering:
 * Once upon a time, house rules were the only way to have a M:tG game with more than two people. Also, rules taken for granted today like the 4-card limit and play or draw started as house rules.
 * Magic: The Gathering can be quite interesting with or without a "draw seven when you run out of cards" rule—the two require vastly different strategies, of course, since such a rule can make emptying your hand a good thing, and cards that return to your hand a severe disadvantage.
 * One particular unofficial multiplayer format that evolved for Magic is the Five Colour Format, which has massive 200 (or 500) -card decks that require all 5 colours to have at least a minor presence in the deck.
 * One way to create a new variant is to add "Alara" to an old variant. In the Alara variant, you can have one color and its two allies, and the other Commander rules apply as well. This bans all four-color and five-color cards, cards like the Skyship Weatherlight (for costing one mana of each color to activate), and any color that requires mana of one color and both its enemies.
 * A particularly popular House Rules format, Elder Dragon Highlander, has its own official unofficial rules put together by people outside of Wizards of the Coast.
 * And now it's been renamed Commander and been given a multiplayer set themed around it, while still not being an official Wot C format.
 * The card game Hex Hex specifically states that whoever wins the game gets to make up a house rule which applies for the rest of the session. Popular ones include not being allowed to say the word "hex" and swapping the definitions of left and right.
 * Uno's house rules have gotten to the point that in many minds they have displaced the real rules. In the original, you cannot stack Draw Two/Draw Four cards, you play for score (number cards are worth their number; Skip, Reverse, and Draw Two are all worth 20, and Wilds are worth 50), with the lowest score winning once someone hits 500 points, and you can challenge Wild Draw Four cards (you're not supposed to play them if you have the color of the card on top of the pile; the loser of any challenge has to draw eight as a penalty). Most people don't play with these rules, to the extent that they won't even announce which house rule sets they play with when the game begins.
 * Those who do know the original rules, though, will sometimes use this to their advantage - particularly if "stacking" is called but removing the limitation on Draw Fours is not. More than one person with an incomplete grasp of the Uno rules has been challenged on their Draw Four play in a stacking sequence, gotten a quick refresher of the rules, and acquired a new Rival after being crushed with a Draw Thirty-Two.
 * Apples To Apples has several popular house rule addendums, including that everyone gets to submit one red card, and that once per game a judge can swap green cards during the judging phase without warning anyone.
 * There are certain card games that are entirely based on house rules. For example, one game called "Mao" has only one real rule at the start; it's exactly like uno with regular playing cards (no draw cards or wildcards), and the winner of a hand can make up a rule each turn so long as it doesn't favor anybody in particular. It generally starts with at least one or two extra rules so that you can trip people up. An even more crazy version of this was a game where you could make a rule any time you played an 8 card, and the rule could do anything besides make you win instantly without playing a card.
 * An interesting variant is where you don't have to tell anyone what the new rule you just made up is. You can merely indicate that they have broken a rule when they do so. This, as the Illuminati example mentioned above, is best played with people you trust or that you'll never see again. Alternatively, the person making the rule up tells one other player, which rotates through the players with each new rule.
 * It's worth noting that it's illegal to talk about the rules of Mao. If you do, your punishment can range from card penalties to a permanent ban (A ban being for explaining the majority of the rules to someone who does not know how to play). You can also not alter the base rules of Mao (plural, there are more than one in every game I've played). The official statement is "The only rule I can tell you is this one."
 * A simpler variant of Mao has one person making a rule (which can be as perversely complicated as they like) about which cards can be played on which other cards, and not telling anyone what it is. Then, everyone else takes turns putting down cards. If their card doesn't fit the pattern, they have to take it back and lose their turn.
 * Nomic and similar games consist of nothing but house rules; that is, in fact, the point - they're an entire class of games where the point is that the rules are altered continuously throughout the game. Needless to say, these games tend to get far more complicated than mere humans can cope with. Several have been running continuously since 1993.
 * Fluxx already has card types that add rules and goals to the game. You can buy Fluxx Blanxx to get the same cards with no text on them.
 * From the publisher of Fluxx comes Icehouse, a bunch of plastic pyramids that can be put on their sides to indicate facing. Then they started publishing game after game that used those pieces. House rules ensued.
 * Crazy Eights. Oh Crazy Eights. The basic rules are a discard while following suit or value. This is the only thing that people can agree upon. The following are but a small example of the house rules one may come across.
 * Eights: Usually wild. Sometimes, they change the suit to their own suit. Sometimes, the player gets to choose the suit they become.
 * Twos: Pick up two. Stacking them usually means the next person picks up 4, then 6, then 8.
 * Jacks: Skip a turn.
 * Aces: "Drop the bomb." This allows you to play every other card of that suit on top of your ace.
 * Queens: Pick up four. Stacking them might be additive, like with twos. Sometimes, you can add the twos to the run. Sometimes, only the Queen of Spades means picking up, and it usually means pick up 5. May or may not stack.
 * Multiples. Do you have tuples of the same value? Why not play them all at once!
 * Knock to declare your last card.
 * And that doesn't even begin to cover Crazy Eights variants, like Crazy Eight Countdown.
 * Similar is Last Card. The usual rules are Ace is wild, 2 is pick up two, 5 is pick up five and 10 skip a turn. Optional rules include Jack is reverse, 7 'blocks' a 2 or 5, or bounces it back to person who put it down. Sometimes pick up cards can be passed on by the recipient by stacking another one on top to add the effect, regardless of whether it is the same number as the original pick up. There can be disagreements over whether someone's win was legitimate if they didn't call 'Last card' one turn, then emptied their hand next turn by putting down several cards of the same number.
 * Outside of tournaments and casinos, even Poker has house rules. A popular one for Texas Hold 'Em is the Chase The Hammer rule, whereby you win a small amount of chips from every player if you win a hand having been dealt a seven and a deuce of different suits, the worst possible hand you can be dealt and nicknamed The Hammer.
 * In Chrononauts, a purely-for-flavor house rule is that whenever you change a linchpin, you have to explain how you're changing it. If someone changes it back, they need to explain how they changed what you did. This can lead to some very amusing chains of events.
 * Hitler was killed by an orbital laser cannon. Then he wasn't, because Bob stole the power source. Then he was, because that was a decoy power source. Then....
 * Also very often in the most popular German card game, Skat. Many of these help to drive the score Serial Escalation (and note that Skat is often played for money, albeit not that much, depending on the score).
 * How Blinds (bidding X books before the cards are dealt) are supposed to work in Spades, or even if said gambit is available. Whether you can call for one anytime or only after you're down X points. Do you automatically get them if you go into negative points? Standard scoring for failed blind or double-points? How they work usually depends on who you play with.

Film

 * Cass in The Gamers: Dorkness Rising argues with Lodge's House Rules frequently. Of course, he is a Munchkin.

Radio

 * The faux-game Mornington Crescent consists almost entirely of the players "arguing" about which house rules are in effect for the particular game. Minutiae such as what day of the week it is, whether the House of Lords is in session at the time of play, and how many buttons are on the shirt being worn by the player to your right can all potentially be of significance.
 * At least once they've tried to play it for a city other than London, before "remembering" that no other city has a Mornington Crescent (although the Edinburgh variant "Morningside Crescent" has proven popular).

Tabletop Games

 * Tabletop RPGs are particularly prone to House Rules, as players introduced to a new system import their favorite rules from other RPGs.
 * Wargames suffer from this a lot. Munchkins often come up with new and unusual house rules to "Improve" the game or to settle some "obvious imbalance". In reality no house rules of this sort were ever good, house rules are supposed to be things like "My hill with trees counts as a hill and a forest" or "The bunker is sealed and indestructible, it's just impassable." House rules should not be "All Eldar always strike first because they are cool".
 * The tiers for this seem to go "More Fun> More Fair> More Realistic> Fluffier
 * Rifts, in particular, is often modified. It's intentionally created with no balance to speak of, and each power, spell, and piece of technology is written without considering how it interacts with the rest of the system. For bonus points, the rules are (intentionally?) just slightly vague. For extra special bonus points, the entire Palladium game system (of which Rifts is a member) is supposedly cross-compatible, but each particular game uses slightly different rules. House Rules to the rescue!
 * Its gotten so bad that the creator of Rifts uses house rules in his own campaign. Frustratingly, he refuses to put them in an update supplement, even as optional rules.
 * Virtually all Pen and Paper roleplaying games have houserules of some kind, and in fact many games encourage a DM to alter or change rules to make for a smoother game.
 * 'You are not playing White Wolf's Exalted, you are playing your ST's Exalted.'
 * One common such rule is 'no takebacks'. Once an action is declared, it is to be taken. This is generally implemented to stop players from endlessly changing their actions based on other people's actions. Intriguingly enough White Wolfs World of Darkness (pre-reboot at least) contained an actual mechanic for changing one's action in the combat round.
 * GURPS suggests 'no takebacks' as an actual rule, with the caveat that if the player regrets their decision on a time frame that would have been fast enough in game, they can undo their action. The example they give is burning a document. If you shout "Wait!" within a few seconds, your character can probably salvage the document. If your character was using a flamethrower on the other hand...
 * GURPS suggests various possible house rules in the sourcebooks. Apparently the most popular house (that isn't suggested) is to separate the extremely broad IQ stat from also raising Perception and Will.
 * That got suggested in Compendium I, before the shift to the newest edition.
 * The Fantasy Trip has several combat rules listed as optional (such as crippling hits). House rules to reduce wizards' dependence on physical strength (so that all the wizards don't look like Arnold Schwarzenegger), or make combat less lethal (so characters don't die off like flies), are popular.
 * Actively condoned by the rulebooks of Warhammer 40,000, which generally operates by the idea that if you and your opponent agree to the house rule, why not?
 * The "snake eyes on a Leadership test means an automatic pass" rule was taken from 40K and absorbed into the Warhammer Fantasy house-rule pool so spectacularly that a) many people were convinced it was an actual rule and b) with the latest edition these people became right.
 * Fans of Warhammer Fantasy got tired of waiting for Games Workshop to publish rules for armies from the parts of the world map that approximately correspond to North Africa and Asia, and set out to create their own army books. To date, Cathay, Albion, Araby, Nippon, and Estalia have got fan-made army books.
 * Warhammer 40,000 has got an expansive group of house rules floating around on the internet, including among other things rules for fighting battles set during the Horus Heresy, a fan-made 5th edition Inquisition Codex, rules for designing your own Special Characters, rules for designing Land Raider variants, and Apocalypse formations for large numbers of Exorcist tanks.
 * These days, Mordheim has been abandoned by GW, so a variety of sources have put together a series of campaigns and variant rules for taking the system out of the ruins of the titular city.
 * Playing Dungeons & Dragons 3.x without houserules is currently pretty much unheard of.
 * In fact, what ended up in 3rd Edition that wasn't in 2nd?
 * Critical hits and misses. Critical hits in (A)D&D were house rule territory. A natural 20 might always hit regardless of the target's armor class, but that hit itself was still a perfectly normal one dealing standard damage with no additional effects by the rules as written. (Now, some magic items like wounding and vorpal weapons would have abilities going off on certain high to-hit rolls, but that was just part of their magic, not the overall combat rules.) Then in AD&D 2, critical hits became an "optional" rule in the book. Unfortunately, one of the suggested options for critical hits was that a natural 20 always hits and deals double damage, so anyone who could only be hit on a 20 effectively had half as many total hit points!
 * So "AD&D 2.5" (Player's Options) got two critical hits options, one of them being a reasonably detailed and unified way to use both Subsystem Damage and Hit Point systems. To handle really big critters (giants vs. zaratan sort of thing) "believably" it needed expansion of size categories, but its uniformity made this trivial.
 * "Confirming" critical hits. PO did it via victim's saving throw. D&D 3 did it via requiring a second attack roll—many players took the opportunity to house rule that part out since it slowed down play.
 * A number of late-run 3.0 books were designed to be easily adapted to 3.5, but still require certain degrees of interpretation.
 * Natural 1's and 20's are very frequent house rule targets across the board. Many DMs consider them automatic success/failure on almost any sort of roll, and sometimes add additional effects to be rolled on a natural 20. By default, the only normal rolls affected in any special way by a natural 1 or 20 are attack rolls and saves. One solution made a better use of the "exploding dice" probability regression mechanics AD&D2 had for firearms. Another used extra condition "and beat the target number by X", used in PO.
 * The 3.x Diplomacy rules are particularly conspicuous, as, by the book, a focused character can persuade a horde of bloodthirsty enemies he does not share a language with to "take risks to aid" him in approximately six seconds. Unfortunately, some common house rules result in things like noblemen refusing to accept taxes from peasants because the deal of "I give you money for nothing" isn't rewarding enough to overcome the level difference.
 * Probably one of the most popular house rules in the third edition is adding experience points after each accomplishment (eg. defeating a monster) instead of at the end of each adventure (as suggested in Player's Handbook). Obviously the limit of one level-up per adventure is usually omitted as well.
 * Original D&D was so convoluted it required much interpretation. Effectively each different interpretation was a house rule. It also expected that you'd have a copy of an earlier game Chainmail and a game from another company, Outdoor Survival. While the Dungeons & Dragons Rules Cyclopedia got all necessary rules within one roof, there were still a few things left undefined but either mentioned in other rulebooks or implied as knowledge in some other random rule. (e.g. Does drawing a weapon require 10 seconds, or does it cause you to lose initiative?)
 * Paranoia is particularly suited for house rules as the players are not supposed to know the rules and the GM is encourages to remove, add or change the game any way they see fit. The GM can even change things as the game is progressing and the players are supposed to praise the decision.
 * Then again, half the time Paranoia is played without any rules as the GM pulls shit out of his ass, rolls dice behind a screen, and pretends to consult charts that don't exist. Typically this is for the best.
 * Players knowing the rules is treason.
 * ICE's Role Master system is designed to be very flexible and encourages the use of house rules.
 * Mutants and Masterminds is built on this trope. In a game where it's very easy (and surprisingly affordable) to get infinite attacks in a round, the core rule book spends a great deal of time letting the GM know that they have every right to disallow certain 'legal' actions. It's also not uncommon for certain rules to be ignored if they'll slow down the game.
 * House Rules for most Hero System campaigns were more about the flavor of the setting than modifying the actual game, though there were always additions to the already long list of Advantages and Disadvantages.
 * The Global Guardians PBEM Universe was based on Hero System. Of course it had House Rules.
 * Big Eyes, Small Mouth, having been built with the entire anime genre in mind, requires House Rules and various GM fiats to keep the vaguely-written, easily exploitable phrasing on the book rules in check. While most of them are internally consistent, conflicts between opposing Attributes can very quickly devolve into shouting matches.
 * Spirit of the Century despite being the first FATE game to hit the market had a notoriously bad stress system that was almost universally house ruled over. There are still a great many variations out there.
 * When Dresden Files came out it used one of these variations to have consequences be conditional, but mostly left things the same save for decreasing just how much stress characters could take. Well, without getting into Toughness Powers.

Video Games

 * A pretty common feature in most multiplayer games is to include options in multiplayer game configuration screens is to remove specific elements, be they maps or items, from play, either for challenge reasons or because they were seen as annoying gamebreakers in a PvP situation.
 * Players of most MMORPGs tend to forbid using health potions during PvP as they immediately turn a skill and/or gear contest into a war of stock attrition.
 * People often impose restrictions on the battle system when doing battling in the Pokémon games, often based on popular tournament formats. The latest release, Pokémon Battle Revolution even allows you to hardwire in these restrictions before the match begins.
 * SimCity, in all its Kobayashi Mario glory, is nothing but a game to be set by Self Imposed Challenges and House Rules. Considering you can even use real-world urban planing and rules, it's no wonder why some incredibly well-built cities awe so many people… unless they used a Game Mod.
 * Real Time Strategy multi-player games often have an agreed "5 minutes no rush" rule, if the game doesn't support it itself.
 * Is sometimes taken to extremes. In Age of Empires, No Rush agreements can stretch as high as 45 minutes, even though the game includes the ability to start with extra resources or later in the tech tree specifically to avoid this issue.
 * Age of Empires III actually made this official with the "Treaty Mode", which prevents all combat until a time limit is reached.
 * It can even go further, some games have common rules amounting to "no subterranean/airborne/warping units can be used until you pass a "gate" or other arbitrary barrier around the enemy base" with ground units. Such rules are designed to prevent base building being a race to build said rapid-transport units to bring in engineers/monks/converters/other capturing units before the enemy can build effective defenses. While it's a noble intent, the rules can be so specific as to be annoying, and often unbalance games where one faction relies on traditional firepower and the other faction relies on stealth/trickery/speed/etc.
 * Most if not all electronic versions of Monopoly have selectable house rules built-in.
 * If you want to make Mario Party even more chaotic than it already is, try skipping all the minigame explaination screens. This is sometimes known as Wario Party mode.
 * Certain multiplayer features of Halo get this treatment. The Living Dead gametype started out as a juggernaut variant in Halo 2. Bungie officially made it a gametype in Halo 3. In fact, the Forge mode for Halo 3 and Halo Reach is designed so that players can invoke this trope.
 * This was also the beginning of Griffball, as well as numerous other games in the Action Sack playlist.
 * In Star Wars Battlefront 2, assault on Mos Eisley has these unofficial rules. #1: The arena is for dueling. #2: Interfering in a duel is a bannable offense. #3: Ayla Secura is cheap. #4: No Yoda either.
 * The Ur-Quan Masters (the modern source port of Star Control II) has quite a few for online games, mostly because the game itself doesn't enforce any standards:
 * Both players are limited to a number of "points" (which indicate how strong each ship is), usually 200.
 * Players pick their teams before connecting. No peeking at the other player's selection.
 * No more than one of any given ship is allowed. Without this rule, one player would be able to get a huge advantage by having multiple copies of tough-to-counter ships, like the Chmmr and Kohr-Ah. A variation is to allow duplicates, but only for ships that are worth less than 30 points (the largest number of points any ship has in the game).
 * Thraddash is banned. The main reason, other than it being a Game Breaker, is the way to use it properly (staying away from the opponent with the afterburner while slowly draining the other ship's crew with the peashooter) drags out games too much.
 * If a stalemate happens, whoever controls the fastest ship at the time is responsible for breaking the stalemate.

Web Comics

 * Here in Plus EV. Be careful to play against Konsta with his own deck.