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 significant 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:
Apocalyptic Logistics: Sure it is probably unrealistic that the survivors After the End can consistently get hold of effective weapons and what not after modern infrastructure is no more, but isn't it badass to see your favorite characters duke it out with some abandoned tanks, and manage to find just enough fuel for them too?
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."
Tabletop wargames are often significant aversions of this rule, because they strive for "realism" (though there are endless arguments about what counts as "realism").
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.
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 DKC3. The DKC games were made by Rareware under a license by Nintendo; however, Miyamoto had much influence on the series' design.
Even then, the series has things like roll jumping (rolling off an edge, then jumping off of the thin air) and team throwing (throwing the current inactive kong up to a ledge, causing the active kong to appear there as well) as platforming tools, hilariously impossible things probably only put in to spit in reality's face.
Cranky Kong: "We apes have no need for the laws of physics!"
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.
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.
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 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! 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 Ace Attorney series is actually Social Commentary. OBJECTION!
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 shit 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.
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.
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 I 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 Animus, which recovers crystal-clear genetic memories of ancestors to the point where Desmond-as-Altair can act in ways that Altair never did 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.
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 the 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. 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: 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.
Command & Conquer: Generals has this is with the GLA using an arsenal of out of date weapons, including tanks from World War II and tractors that spew out poison, that are far more effective in game than in real life, and American which would be overpowered if its units were as strong as they were in real life.
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.
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, Canteens that can be filled with stuff that gives you bullets when you drink it....and yes, all because its fun.
Two small but significant examples: The Demoman is a heavy drinker and The Spy is frequently seen smoking cigarettes (it's almost part of his trademark), yet both are perfectly medically sound to be fighting a war and never collapse on the battlefield from ailments brought on by years of their bad habits. What kind of fun would that be if they did?
Possible justification: The Medi Gun keeps them coasting along nicely.
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?
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.
Because the previous incarnations were defeated by the transcendent one in his fortress, who took the memories to prevent you to regain your mortality. In gameplay there is one place where dying means game over, because dying there will cost you your memories.
This was explained in the novelization (yes, there was one). The Nameless One had made a deal with a Baatezu: "Save my village, and I will fight in the Blood War". So it did, but The Nameless One reneged on his deal. It took the Baatezu a few centuries to figure out how to make a potion from the River Styx (which normally wipes your memories if you drink it) that would PREVENT The Nameless One from losing his memories the next time he died; all part of the Baatezu's gambit to get The Nameless One to fulfill his end of the bargain.
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.
Puyo Puyo has a pretty basic concept; connect four jellies of a kind to make points and trash for the opponent. What makes this fun is the fact that it tests your ability as a player by also testing how good you can get at the game by throwing everything a puzzle game could do at you. Then they add the Rule of Cool by having the backstory revolve around a six-year old child going off to face and defeat the forces of darkness and Satan. Then they toss in the Rule of Funny by making Satan a Bishounen male with long green hair attempting to go out on dates with the now 16 year old girl. Then it becomes batshit crazy with dancing-on-feet-with-arms salmon, maids who are obsessed with cleaning, dragon-lady fanclubs, books possessed by demons who never do any real damage, talking cat puppets that want to take over the world, gay skeletons... At some point the plot gave up.
There is no real reason for building everything out of Lego and/or destroy it. There is no reasonable explanation for switching characters in the blink of an eye (Slitherins in the Gryffindor room; boys in the girls' toilet). There is no suitable explanation for playing the beginner's mission with a character that has learned spells from four years. It's just so much fun!
Also, at least one game was scrapped with the explanation from the developers: It just wasn't fun to play.
Radiant Historia keeps Stocke's party members' levels and equipment consistent between the two timelines, and even when jumping back and forth along the same timeline. This directly violates the rules for time travel in the game that are spelled out and otherwise strictly stuck to, but prevents the first part of each new chapter being a grind-y slog.
The WWF/WWE Smackdown series was built on this trope, after years of wrestling games requiring combos for the simplest of moves and offering little backstage areas or customisation. However, from the first Smackdown Vs Raw game onwards, the decision was made to make the games more realistic by doing such things as light wrestlers not being able to pick up certain heavy ones, and limb damage, and removing many of the weapons and backstage areas. Later games even removed the ability to have males and females in the same match. Whilst the game presentation was well received, these changes were not well received amongst fans, but the company continued to implement them anyway.
In El Goonish Shive, this is the author's stated reason for just why transforming is ridiculously, absurdly safe.
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!
Averted though for some as this very wiki (as a concept and any given article) is often a surprizingly useful tool and aid in creating a common language of fun and creativity. The fact that it's fun is for those people is probably due to the same reason a physicist might enjoy adding something to the other wiki article on physics.
Parodied by The Onion, when they touted Call of Duty: Modern Warfare 3note this was right after MW 2 was released, mind you, and the real game wouldn't be announced for years 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.
Invoked a commercial for Boost Mobile with a lady talking about how she went to a "bangin' party" to get her "freak on." It says on-screen that the service is designed for young people "but it's just more fun showing old people."