Rule of Fun

""While it might be 'realistic' for a nearly dead character to limp, move slowly, and have generally less effective moves, it's not fun.""

- David Sirlin on Street Fighter

""Don't argue with the logic of this, just play it!""

- TV ad for Adult Swim's Mr. Mullet flash game.

Games must be fun to play. Sure, we like pretty graphics and a good plot, but the fun's the main thing. If they're fun, a lot of incongruities can be forgiven. Go ahead, try to explain why the yellow circle loves dots and why the ghosts are out to get him, or why the frog needs to get across the road. You can explain why but it doesn't matter. The purpose of the game was to have fun in the first place.

This was most evident of the very early days of video games, when technological constraints put a limit on the amount of depth or detail a game could have. Back then, designers made sure a game was fun first, then devised a reason later. Besides, all games are basically just a bunch of colliding rectangles anyway—why get too worked up about what the designers decided to cover up the rectangles with?

Of course, this also applies to non-video games. It's possible to create a Tabletop RPG that emulates a medieval swordfight down to the smallest detail—but not many people would find that fun ('real' swordfights were typically very brutal and incredibly brief, which is the antithesis of 'fun' in an RPG); thus, we have Hit Points.

A nonsensical premise, a bizarre story, weird gameplay mechanics—all of these things have no choice but to bow their head if the game is fun. This is the Rule of Fun. See also the MST3K Mantra, the Rule of Cool, and the Rule of Funny (which, by the way, is a quite different trope).

The Rule of Fun extends to game design, as well as game play: while being a blacksmith, or a tailor, or an engineer, may be fun, the details of the professions (such as the technical aspects of smithing, or the time investment reqired for tailoring) are decidedly not—therefore, the professions are usually loaded down with lots of neat 'fun' stuff, while conveniently skipping over the fact that there is signifigant effort involved in the actual production process.

Tedium and boredom have always been the traditional 'enemies' of entertainment. A well-designed game with quick pacing and lots of action will be fun to play; likewise, a game that is badly-scripted or hampered by a badly-executed concept is likely to be very unintuitive and will bore the player.

Tropes that exist partially or totally due to the Rule of Fun:


 * Most of the Acceptable Breaks From Reality exist to keep that pesky "realism" thing from interfering too much in the fun.
 * Awesome but Impractical
 * Bragging Rights Reward. Sure, you might not need the Infinity+1 Sword, but... isn't it cool?
 * Button Mashing
 * Excuse Plot
 * Fake Skill
 * Fake Longevity
 * Fake Balance
 * Fake Difficulty: Yes, even these are usually invoked to promote the Rule of Fun.
 * Finishing Move
 * Self-Imposed Challenge
 * Violation of Common Sense
 * Wide Open Sandbox

Tabletop Games

 * Tabletop wargames are often significant aversions of this rule, because they strive for "realism" (though there are endless arguments about what counts as "realism").
 * Some editions of the post-apocalyptic RPG Gamma World explicitly cite this rule as the major determining factor whether any given artifact survived the holocaust to be found and used by the player-characters.
 * Warhammer 40,000 mainly runs off of Rule of Cool and Refuge in Audacity, but the overall effect follows the example of Rule of Fun quite a bit, too. How can a Tyranid that big pop up behind enemy lines without warning? How can those Imperial Fists scouts move unseen through sparse foliage wearing neon yellow power armour? Why are there (optional) rules for using a Baneblade in smaller-than-Apocalypse games? Because it's cool and fun, that's why.
 * The primary reason the most common dice roll in Dungeons & Dragons is an attack, rather than "DC 17 Profession (farmer) check."
 * One of the most dramatically complex wargames ever is The Campaign for North Africa. The map is 10 feet long. The game is supposed to take 1,200 hours with 10 players. Most of the time playing the game is spent doing paperwork about food, fuel, uniforms, ammo, water, truck convoys, prisoners of war (you gotta feed them!), and so on. The game rules specify that Italian forces use more water than the other nationalities because they eat a lot of pasta. The water for the Brits evaporates faster than the normal rule at the beginning of the game because of the design of the cans they used. Yes, you're supposed to track all of this. By hand.
 * From this it's easy to see why most games go for Easy Logistics. Of course, for some, keeping track of all that is fun, so it's a matter of taste.
 * An actual rule of Paranoia, mixed with the Rule of Funny. (A lot of the time, the dice are really just suggestions).
 * The goal in overhauling the rules for the 4th edition of Dungeons & Dragons was to strip out the tedious elements and focus on the fun simplifying character builds and fight mechanic while retaining options and even expanding tactical opportunities. The debate comes from stripping out mechanics that supported non combat/adventure situations and limiting certain character build decisions. Roleplayers argue that this either removes support for anything aside from combat or frees them from the constraints of things like mechanics based parley.
 * Basically, if you're a gamist, 4th edition is probably a move in the right direction, if you're a simulationist, you're less likely to be happy.
 * And then there are those for whom half the fun is spending a few hours planning out a characters level progression, and dont find 4.0 to be as fun because there is little planning involved (no true multiclassing, so every ranger is rather similar to every other ranger, while in 3.5, my rogue3/ranger3/bloodhound10 it pretty much unique.
 * The 50-50 rule in Toon. It basically says "If anything happens in the game that you don't know the answer to, frame it as a yes/no question and roll a die. If it lands on 1-3 the answer is yes, 4-6 no." The justification is explicitly that this is more fun than stopping the game to think about it.

Video Games

 * Rule of Fun probably had something to do with why the wasteland in Fallout 3 looks more like it was bombed with conventional bombs than nukes: it just wouldn't be very interesting otherwise. Indeed, it accounts for many things in Fallout: the way some places are as radioactive as if World War III was yesterday, that the radiation has created lumpen Super Mutants and giant rad-scorpions instead of just death; the applications of Mad Science and pre-war AIs and Energy Weapons; odd special encounters that reference original Star Trek and Doctor Who.
 * The Mario series is essentially based off this trope. The original concept was that of a carpenter named Jumpman saving a beautiful lady from King Kong, no, Donkey Kong by jumping over barrels. This was evidently decided to be too unrealistic, so the designers decided the carpenter would actually be a plumber called Mario, the beautiful lady would be a princess kidnapped by a giant fire-breathing turtle, and the plumber would become larger by eating mushrooms, shoot fireballs by collecting flowers, and harness the power of those famed aeronauts, tanuki, to fly. The later games in the series (particularly the Paper Mario subseries) have mercilessly lampshaded the series's bizarre origins.
 * Shigeru Miyamoto has been known to attribute a fair bit of his success to this trope. People can wilfully overlook anything if it's enough fun.
 * Regarding Link's Crossbow Training, Miyamoto said that firing a crossbow rapid-fire like a machine gun is very unrealistic, but he quickly decided he didn't care as long as it was fun.
 * The same goes for the Wario series, or the Donkey Kong series, or the Yoshi's Island series. Pretty much all of them based on the same 'How fun but completely and utterly crazy can the designers make these games?' formula.
 * The Donkey Kong series is by far the most "realistic" one of all the Mario-verse game series, though, at least as far as Donkey Kong Country is concerned. The settings are very naturalistic and the baddies look like your average fantasy / sci-fi evil reptilian race, even if the series as a whole does angle toward the cartoony side of things, especially in DKC 3.
 * It's important to keep in mind that the DKC games were made by Rareware under a license by Nintendo. However, Miyamoto had much influence on the series' design.
 * The biggest modern example is the Katamari Damacy series. It's best not to think too hard about that premise, really. Just roll the ball already.
 * The Phoenix Wright: Ace Attorney series is based off a complete bastardization of any fair and just legal system, wherein a single line of false testimony from a barely credible witness can completely screw your client, but that's okay—more fun that way! OBJECTION!
 * It is confusing for anyone in America to imagine a juryless court system in which the burden of evidence is on the defense, but in Japan, the Justice system was actually a lot like that until recently. That's right, the off-color justice system in the Phoenix Wright series is actually Social Commentary.
 * In Space Channel 5, you play a TV reporter who's fighting off an alien invasion. The aliens haven't come to talk, though. They've come... to dance! Only by shaking your booty can you thwart the hordes of colorful rubbery aliens!
 * In the popular flash game Insaniquarium you have to feed your fish. Because they poop money. Oh, and you'll need that money to upgrade a laser cannon to defeat some evil aliens. Naturally the aliens want to eat your money-pooping fish. Goes without saying, really.
 * In the Nintendo DS game Osu! Tatakae! Ouendan, Japanese cheerleaders help people complete all kinds of tasks, from getting into a good college to fighting giant monsters to saving the world, by cheering them on to a selection of J-pop and J-rock hits.
 * Similarly, its American counterpart/sequel Elite Beat Agents, where The Men in Black fight off alien invasions, resurrect the dead, help the helpless, and save the world—with The Power of Rock!
 * The Sonic the Hedgehog series is about a hedgehog with superpowers who saved small woodland animals from being turned into killer robots/the world from being taken over by an evil fat man with a robot fetish. Said hedgehog, with the help of some Green Rocks, can also apparently go Super Saiyan. At its peak, this series matched the popularity of Mario and Zelda.
 * Super Smash Bros.. is probably the distilled personification of this trope. Why are an electrically charged rodent, an Italian plumber, a speedy blue hedgehog and an elfish tunic-wearing hero duking it out with lightsabers on top of a spaceship? Because it's awesome!
 * The intro to the original game contains an implication (that the game is basically a kid making his toys "fight") that you can either accept or ignore—whichever is more fun.
 * The Melee opening refers to that too, except with small trophies.
 * 1998's Grand Prix Legends was a classic example of a spectacularly non-fun game. On paper the idea of a driving game set in the 'sixties, with the promise of classic F1 cars and tracks, was tantalizing as it had never been done before. Unfortunately, the game was such a rigorous simulation that it was staggeringly difficult (even if you had a real driver's license) and virtually impossible to play competitively without hours and hours of practice. It was so tough that the paltry driver aids that were provided actually made it worse, since the only way to control the car was to shift manually and double de-clutch like a pro. It was even argued that before force feedback controllers came along the game was actually harder (if not as scary and dangerous) than the real thing.
 * However, for avid sim racers, keeping the cars under control is part of the fun.
 * A lot of Assassin's Creed is like this, especially the short distance between the major cities of the Holy Land. At some point having to ride across the vast landscapes would just get dull. The historical accuracy also tends to stop right around the point where the fun begins, such as Altair's signature spring-loaded hidden blade.
 * In terms of real world logic the  makes absolutely no sense at all, but it works for plot purposes, making the Animus an example of Phlebotinum as well.
 * The business with the hundreds of collectible flags being hidden in random places for no reason is also historically inaccurate.
 * Tetris. Make the rectangles combine until they disappear. Then keep doing it until you lose. The reason? There are no reasons but that of attaining ever higher levels.
 * Level 999 then Invisible Tetris in Tetris: The Grand Master 2 and 3.
 * Dance Dance Revolution, in which the whole point of the game is to press the arrows at exactly the right time by dancing.
 * Really, any Rhythm Game but let's single out Guitar Hero and Rock Band.
 * Beatmania and Beatmania IIDX, despite their descriptions, are nothing like real DJ'ing. But who gives a crap? And then there's Pop'n Music, which doesn't even simulate an instrument at all.
 * Freelancer. Just ignore the grossly warped scale (entire planets only a few times bigger than a little starfighter!), enjoy the exquisite artwork, and play some good Old School Dogfighting.
 * A few things to keep in mind with the whole sense of scale thing. First of all, you have to remember the point of view you have in the game; right behind your spaceship, whereas even coming up to dock with the planet the view never shifts to within its atmosphere. For a simpler explanation look here; http://www.youtube.com/watch?v=25N-4zrk390. Secondly, even if the planets are still fairly small compared to say Jupiter or Saturn, there's nothing wrong with that. Most of the planets seem to be uni-ecological which would in fact make more sense on a smaller planet than a larger one. Finally, if the designers had sized up the planets they would also have had to increase the distance between them to keep the whole thing proportional, it already takes ages to get from one place to another in that game without the possibility of having to circumnavigate a gas giant half way through a journey.
 * Command & Conquer: Command & Conquer: Red Alert 3 had such a nonsensical premise, a bizarre story, weird gameplay mechanics, strange history, and implausible science (the side with helicopters armed with Freeze Rays and Shrink Rays was probably the most sensible) and crazed Ham-to-Ham Combat in the mission briefings that trying to think about it too hard will make your head hurt. So, don't think about it, and have (a lot of) fun.
 * Taken completely seriously at face value by the Red Alert 3: Paradox Game Mod, then stuffed into a blender with other game genres, creating 5 new factions and a rooster of minifactions. If you thought Command & Conquer: Red Alert 3 was crazy, then Paradox gives you the possibility to play an RPG, SimCity or a Tower Defense game (notably both the towers and the creeps as separate factions) in a Real Time Strategy game. To top it off, the mod is growing in size due to its fanbase who try to think of ever newer factions.
 * Prototype has some pretty noticeable moments of bizarre physics, such as leaping forward and suddenly doing a flying kick/cannonball at a target in the opposite direction, thrown objects like cars that have even but a very limited degree of homing capability, having an extreme disparity in damage potential between a simple fall and a bullet-dive drop both from say seven stories high, running horizontally on the CONVEX side of a vertical plane, the loooooong hang time of doing a max air combo... the list goes on. But it's fun. Especially the cannonball.
 * Blast Corps. A damaged nuclear missile needs to take the most direct route to a safe demolitions site, but there are a bunch of cities blocking its path, so the player needs to destroy them all. Why do you get to choose which order to play the cities in? Why do you get a medal for destroying all the other buildings that weren't in the way? Why can't you fly the impervious mecha all over the place instead of having to use what amounts to a big pick-up truck for half the levels? And why can you spend all the time you feel like fiddling around with bonus levels, when the missile is always a few seconds away from crashing whenever you enter a mission critical city? And why isn't there anyone else to help you? Who cares, It's fun!
 * Word of God stated that the driver had a glass of fruit juice balanced on his dashboard and turning would knock it off and ruin his upholstery, which is why he couldn't turn. It was the director who said this, but he was obviously having a laugh at the fact that fans demanded an explanation.
 * The Wangan Midnight Maximum Tune series allows you not only drive a car with horsepower in excess of 700 without it breaking down at all, but a 700 HP, full-tuned car has balanced handling. And this is without discussing the super-drifty, yet spinout-proof physics that make the game more accessible to beginners than, say, the Tokyo Xtreme Racer series.
 * Team Fortress 2 may very well be the FPS example. Why is a minigun that weighs 150kg possible to carry, let alone fire? Because it's fun. Why is the rocket launcher semiautomatic? Because it's fun. Why does whacking a machine with a wrench cause it to grow gatling turrets? Because it's fun. Why does a paper mask make one identical to the face on the mask? Because it's fun. Why is an energy drink able to make someone invulnerable? Because it's fun. How does a sandwich heal bullet wounds? Because it's fun. Why is leaping over a sticky bomb, then detonating it, a valuable combat tactic? Because it's fun. In fact, the reason the game stopped being a realistic military shooter is Valve realized how preposterous most of the above was, retooled the game, and then got away with the rest.
 * Actually, the whole "whack the sentry gun with the wrench" was explained in the game's instruction manual, which was nothing more than the Sentry-brand automated gun's owner's manual. Turns out it's to loosen some of the bolts so that the gun assembly could expand. Still, even if the manual uses a lot of Techno Babble to explain the technical aspects of the Engineer's work, it's all euphemisms for "smack it with a wrench".
 * Over time, the game has slowly become even more ridiculous. You have Pyros running around with birdcages on their heads, giant disembodied eyeballs attacking the battle-field, evil magicians sending people back in time, the Engineer looting crashed space-ships, icicle knives that somehow freeze people, Snipers deciding that arrows really are better than modern rifles....and yes, all because its fun.
 * Backyard Sports. A baseball/soccer/football/whatever game with zany powerups, not to mention that you can play as a kid in a wheelchair, kids who wear glasses while playing, and a robot. How fun is that?
 * For all intents and purposes, Final Fantasy X-2.
 * Zombie mode in any Call of Duty game. Battling the undead, fair enough. But using points to buy bigger and upgraded weapons, the demonic announcer, nukes that only kill zombies...RuleOfFun to the max.
 * Planescape: Torment: Why doesn't The Nameless One lose his memories any more when he dies? For one, it wouldn't make for a terribly rewarding game experience if you lost all your progress in the game each time you did.
 * Believe it or not, the ARMA series' vehicles are greatly simplified for this reason, as the game is already completely in the opposite direction when it comes to people and small arms.
 * The developers of the Civilization series seem to be fond of this rule. The "developer's notes"-section of Civilization IV's manual explains several features they had planned and how they evolved to their final forms - and the Rule of Fun is cited many times as a reason for changes.
 * This trope is the only reason why in Mystery Trackers 3: Black Isle you can lug around in your inventory, not just a welding machine or a wheelbarrow, but a welding machine in a wheelbarrow.
 * The Tomb Raider series has a handful of inaccuracies and "how the hell can that happen!?" moments, but the games are just so much fun that you tend to not care. Gorillas within some ruins in Greece? Sure, why not? Blasting a T-Rex in Peru with dual pistols? It's cool! Infiltrating a military research base in the United States to obtain the MacGuffin? Go nuts! Fighting a punk teenager in an underground skating arena filled with lava pits as he rides a skateboard and shoots you with uzis? Hell yes. The developers pretty much admit most of the stuff they did seem quite ridiculous now when they think about it, but it's so much fun to engage the events that you don't care how out of place they may look.

Web Comics
"Amanda: (Evil glare) It's more fun that way. [KRAK-A-THOOM!]"
 * In El Goonish Shive, this is the author's stated reason for just why transforming is ridiculously, absurdly safe.

Western Animation

 * Transformers is possibly the most Merchandise-Driven franchise in the world, that exists and always existed pretty much solely to sell toys. But they're really good toys, so we have no problem with it!
 * Cartoons in general. Why else would a person draw and show off pictures of a mouse whistling in a boat to a personified sea sponge and anything and everything in between and MORE? Because it's FUN.

Other

 * Parodied by The Onion, when they touted Call of Duty: Modern Warfare 3 as the most realistic war simulator ever. Over 17,000 hours of gameplay, much of it spent in pointless debates over whether Shakira is hotter than Jessica Biel, standing on guard, and fixing vehicles for 10 hours a day! Gamers clearly want realism, so now you can truly live the life of an Army private!
 * The Onion has taken it to the other un-fun extreme with a game that consists of nothing but shooting people in the face, point blank, with no strategy or challenge whatsoever.