In video games or Tabletop Games, an element of the gameplay that is supposed to make the game realistic, but eventually makes it laughably unrealistic.
This generally occurs in one (or in some cases more than one together) of three ways:
An effect is included for "realism", but the effect's magnitude or immediacy is grossly exaggerated.
A tactic is included for "realism", but real-life considerations that limit the tactic's effectiveness (such as logistical problems, possible countermeasures, or the difficulty of pulling it off) are downplayed, making the tactic unrealistically effective or dominant.
"Realism" is strongly enforced with respect to one aspect of the game, but not to other, closely related aspects, leading to unrealistic play dynamics and silly situations.
In the Metal Gear series, the cigarettes Snake smokes are bad for his health, which is understandable. What is not understandable is how they kill him in two minutes. This is mostly likely to give kids the message smoking is bad, though why the developers would want to impart this message in a game marketed mainly towards adults is a mystery.
Metal Gear Solid 3 has the Cure system, where Naked Snake could be injured by various means (such as an animal bite, gunshot, or other trauma) and he would have to break out medical supplies to treat his wounds. While it can provide more immersion, it also leads to the situation where Naked Snake can set broken limbs dozens of times, carve any number of bullets out of his flesh, and other sorts of field expedient medical procedures, even when by rights such things should leave him laid up.
On the other hand, it does give you a good sense of why everyone else further along in the timeline regards Big Boss with sheer awe.
Deus Ex: many of your portable items, such as tech goggles, have battery life. Considering that tech goggles are military equipment, it sure is strange that they can only be used for about thirty seconds before completely crapping out.
Denton's superhuman inability to hold his liquorseems like Misaimed Realism, but is justified as a consequence of his nanite-enhanced metabolism. They help to pass intoxicants through his system more quickly, but in doing so exaggerate the effects for a brief period.
The Elder Scrolls IV: Oblivion has NPCs react quickly and decisively if they spot the player pilfering - in the interest of making the game more realistic, obviously. Instead, however, the result is that a horde of guards descend on you like flies on honey, if you so much as touch an item that doesn't belong to you. The classic example is that of first-time players entering a store for the first time, accidentally jostling an object off a table, and politely lifting it back up to the table... only to be instantly mobbed by overzealous guards.
This is particularly egregious if you try to interact with a Quest Giver and accidentally take something instead. Sometimes they'll scream for the guards to come and take you away, then politely wait for you to interact with them as if nothing ever happened.
Yet, strangely, people have no problem with you walking into their store, pulling out a sword, and knocking everything off the countertop with it.
In GURPS when you fire buckshot the weapon you're using has zero recoil. This is because listing proper recoil for buckshot would screw up the accuracy of the hit roll.
The third entry in the Thief game series, Thief: Deadly Shadows, had a rag doll physics version of this. The much-hyped but imperfect ragdolls (a new concept few games have tried back in 2004) were supposed to increase the realism of bodily movement. What they ended up doing in practice was making bodies bend into unusual shapes, completely ruining any sense of realism in the silliest way possible. The backwards U, as though the body's spine was reversed, was a particularly common posture.
In Call of Cthulhu: Dark Corners of the Earth, the game does not simply drain your life bar when you're hit and kills you as soon as it's empty. Rather your character can suffer injuries in specific body parts, and the effects vary depending on what type of injury it is; i.e. a broken leg slows down your movement while a flesh wound will cause you to slowly die from blood loss. Likewise, the game also requires different types of treatment for the different injuries, namely either bandaging, suturing, or setting the bones with splints. The treatments also happen in real time, meaning your enemies can still stab your character while he's trying to stitch up that gash on his chest.
The unrealistic part of this is that the treated wounds heal so quickly that there are no lasting effects from any particular injury; the end result is your character will end up breaking and fixing his arms and legs about fifty times and stitching himself up so frequently that he should look like Frankenstein's monster by the end of the game. As far as why they decided to include some realistic elements into this health system that's still otherwise highly unrealistic isn't clear, though being in a horror game, it's very possible it was just done for the sake of grittiness.
Many games on the high end of the Fackler Scale of FPS Realism attempt to model "realistic" bullet damage by turning you into a One-Hit-Point Wonder. They never bother to completely model bullet effects such as the differing effects from where the bullet hits, the effectiveness of modern body armor, and so on.
The Short Range Shotgun. While real-life shotguns do lose accuracy and stopping power at longer ranges, the drop-off is nowhere near as extreme as portrayed in most games.
Snipers are well-known for their ability to find a decent spot, observe a target, and kill them with a single bullet from a great distance. But even disregarding the training necessary to be effective at this, there are multiple factors such as gravity and wind that must be taken into account, and it takes a good deal of time to properly line up a shot, especially against a moving target... and more so if there are multiple targets. Basically, you would not be able to easily aim at and kill anyone who comes into your field of view with one shot each, and certainly not with the effectiveness often abused in an FPS deathmatch.
A discussion on a Dungeons & Dragons fan forum referred to this as the "bag of flour problem". The issue was that providing bonuses to certain tactics because of "realism" (e.g. in a battle in a kitchen, grabbing a bag of flour and throwing it in an opponent's face to distract him) would lead to players performing unrealistic stunts in order to get that bonus all the time (e.g. walking around carrying bags of flour all over the place to use in every combat).
Examples of Partial enforcement:
The LARPsDagorhir and Belegarth have rules that state that if two of your limbs have been disabled by hits, you are dead, to represent blood loss. But since "realistically" piercing attacks cause less blood loss than slashing or crushing attacks, pierced limbs don't count toward this limit. This often leads to players looking silly as they hop around like the Dark Knight in Monty Python.
In Grand Theft Auto: San Andreas, your character can faint if he doesn't eat enough. However, he can stay for weeks if not months without eating or drinking anything before he even feels hungry. Also, the lack of food doesn't prevent him from running, jumping and fighting like an athlete, and workouts will make him look buff even if he's starving.
In Condemned: Criminal Origins, some doors can be broken with an axe. The key word is "some;" why doesn't it work on all of them, considering most of them are made of wood? Also, locks can be smashed, but only by sledgehammers. All other weapons, no matter how heavy and/or strong, can't do that (though these examples are closer to Fridge Logic than Misaimed Realism).
FATAL has this all over the place, but in one specific example, there's a massive table of organs that can be struck by a critical hit. Two problems: the table seems to assume that you hit nothing else on the way there (such as striking the liver but missing all the organs in front of it), and the fact that there's no correction for organs people don't have (meaning you can hit a man right in the ovaries).
Among 4X RTS games, Star Ruler is fairly realistic, with newtonian motion, no Space Friction, instantaneous continuous-beam Frickin' Laser Beams rather than the painfully slow bolts normally used, and with "speed" effectively being "how fast you can accelerate", like on a real spacecraft. However, relativity is not implemented, which results in the game having, once you research enough, lasers that travel faster than the speed of light, and it being possible to exceed the speed of light by simply accelerating long enough.
The second edition of Dungeons & Dragons had the Potion Miscibility Rules. The idea was that if you drank multiple magical potions that you found in a dungeon, they might have unintended side effects. The problem was that the side effects were determined by a random table and had nothing to do with the potions themselves, so there was no way to learn which potions were compatible through trial and error or through study. It was also impossible to replicate beneficial side effects. On the whole, it became a frustrating mess that left the game even less realistic than it was before.
In an effort to avoid Bag of Spilling, Metroid: Other M restricts Samus from using all her abilities by saying she has them, she just isn't using them to cooperate with the military's investigation of a spaceship that suffered some crew-killing disaster. Given she's a walking nuclear tank and some of her weapons could indeed cause a lot of damage to sensitive areas and survivors, this is all well and good... until it comes up that she's also apparently been ordered to disable completely defensive abilities, too, such as the ability to not take damage from heat.
In Deadly Premonition, the game plays out in real time if you let it(I.E. it takes one hour for the time to go from 2300 to 2400), but you can skip ahead by sleeping or smoking cigarettes, this isn't a bad thing, as there are plenty of sidequests and trading cards to collect, which makes that extra time come in handy.
A less convenient example is your car, see unlike most open-world games, your car can actually run out of gas and you have to go to the gas station to fill it back up, and if you run out of fuel far away from any other cars, then you have to use a road flare to restore your cars damage and fuel. What makes this especially glaring is that during certain areas(chapter 5) and in checkpoint races, your car cannot take any damage and has unlimited fuel.
There's also the weapons system, like the Condemned series, melee weapons will gradually wear out from use until they break, forcing you to get new ones...or just use your starter pistol which has unlimited ammo(you can also unlock unlimited ammo for the other firearms as well).