[[quoteright:100:[[VideoGame/BillyVsSNAKEMAN http://static.tvtropes.org/pmwiki/pub/images/The_RNG.jpg]]]]
[-[[caption-width-right:100: [[Franchise/CodeGeass The only people who should roll dice]] [[FinaglesLaw are those who are prepared to roll a 1]].]]-]

->''"If a statistician hands you a die insisting that 'any given roll has the same odds of rolling a one or a twenty', it means '''he's handing you a depleted die in the hopes of taking advantage of you'''. Don't fall for it!"''
-->-- '''Shamus Young''', ''[[http://www.shamusyoung.com/twentysidedtale/?p=1223 DM of the Rings]]''

'''"We guarantee that each number is random individually, but we don't guarantee that more than one of them is random."'''

''Also known as RNGesus, if you're feeling [[JustForPun punny]].''

A [[ArtisticLicenseStatistics statistician]] can tell you that properly generated random numbers will follow a discrete uniform distribution, giving you a roughly equal chance of rolling very good or very bad numbers. They may wax eloquent about how pseudo-random numbers are generated in computers, and how UsefulNotes/{{dice}} are wonderful randomizers. A good statistician will even disabuse you of the notion that a six sided die has an exactly 1/6 chance to land on any one side; most dice are not built to that kind of precision. (Casino craps table dice are. They're also more expensive.) But it's going to be close to even distribution, even with a cheap die.

A gamer, either of the [[TabletopGames tabletop]] or [[VideoGames video]] variety, will tell you that this is all [[UnusualEuphemism a load of dingoes' kidneys]]. The characters that gamers play live and die on [[CriticalHit good]] or [[CriticalFailure bad]] rolls, and even if your dice are perfectly square and uniform, even if your game uses cryptographically strong random numbers, these numbers do not follow "distributions" or "probabilities." Instead, they usually produce whatever number you ''[[FinaglesLaw really didn't want]]''. A tabletop gamer may say that "the dice are trying to kill" them if they encounter a long series of bad rolls (e.g. broke every weapon he was carrying). Unless, of course, you know the proper way to placate the Random Number God: then the dice will smile upon you. Usually.

The name of this trope comes from VideoGame/{{Angband}}'s and VideoGame/NetHack's fanbases ([[TropeMaker coined in the Angband fanbase]], [[TropeCodifier spread by Nethack's]]), as a fanciful expansion of "RNG", for "UsefulNotes/RandomNumberGenerator"; both games are partially {{Luck Based Mission}}s, considering how many [[KilledOffForReal Instant Death]]s there are, and the players of both games have been known to build altars to the "Random Number God" or curse his/her/its name. Or both.

Some games try to cut out the nonsense by supplying their own LuckManipulationMechanic. This never works -- the Random Number God is not mocked, and it'll find a way to mess with you regardless. In RealLife or certain other situations, a TwoHeadedCoin can masquerade as a mere minion of the Random Number God up until TheReveal.


[[folder:Anime & Manga]]
* ''Manga/{{Saki}}'' proves that this trope applies to mahjong tiles as much as it does to dice. Nodoka [[AgentScully refuses to believe]] in players being "loved by the tiles" and such, but other players' freakish abilities to defy all probability when playing (as someone mentioned on the page, "how much can we make a statistician somewhere cry?") pushes her into FlatEarthAtheist territory.
* In ''Quick Start!!'', a 4koma about tabletop gaming group, a resident powergamer Karasuyama Sachi is on RNG's bad side, despite buying dice with equal distribution.
* In ''Manga/RecoveryOfAnMMOJunkie'', Hayashi hears about a special lootbox event and declares that he wants all the rare items. His guildmates cringe and warn him that he's triggered the "Greed Sensor", which responds to greedy players by ensuring that they'll only get bad pulls. True to form, for a while Hayashi rolls nothing but common healing potions (though he does eventually get one of the rare items). Lily, on the other hand, gets every single rare item...[[TheGamblingAddict because she's the type of player willing to buy lootboxes until she gets everything she wants]].

[[folder:Comic Books]]
* In ''ComicStrip/KnightsOfTheDinnerTable'', related to Hackmaster, a character was once beaten to a pulp for touching another gamer's dice. He was blinded by a cupful of soda and then was on the receiving end of a flying tackle. No one (except [[CommanderContrarian Sara]]) thought that this was uncalled for, as "that's one dice squirrel who'll think twice before touching another man's dice!"
** The attacker in that scenario was the 5'3" pencil-necked Bob Herzog, and the man who touched his dice was the 6'11" ex-marine Nitro Ferguson, and every time the event is referenced (the fight itself was [[NoodleIncident never shown]]) it is strongly implied that Nitro got hurt ''at least'' as bad as Bob did.
** In the strip, they even outlined a "dice cleansing" ritual, used to banish bad luck from the character's dice.
** Many dice superstitions are explored in this strip. Bob refers to his dice by name, keeps them segregated according to purpose and game genre. Dave refers frequently to having his section of the table "trained" the way he likes it for dice rolling. All of the Knights, even the sensible Sara, have dice rolling styles. But the most infamous incident had Brian and Bob "fame-rubbing" their dice on Gary Jackson's corpse (a "legendary RPG creator" pastiche of Gary Gygax and Steve Jackson) to charge them with good luck. This backfired because Gary, being dead, was obviously out of good luck (as Sara pointed out, someone who'd died in a plane crash couldn't have been very lucky to begin with). All the fame rubbed dice performed poorly in game play. (Or possibly because [[spoiler: that corpse wasn't Gary Jackson's.]])


[[folder:Light Novel]]
* ''LightNovel/OnlySenseOnline'' has the RunningGag of Sei getting repeatedly screwed over by the "greed sensor" (the same as ''VideoGame/MonsterHunter'''s desire sensor, mentioned under Video Games), as the random loot distribution system in the game is almost guaranteed to hand over whatever she wants to another party member or someone who comes shortly after her, often forcing her to grind excessively or make expensive trades. Meanwhile, Yun's sheer indifference to whatever drops eventually gives him a reputation as a lucky companion, especially since he's willing to trade fairly if he got what someone else wanted.

* The Bible says in Proverbs 16:33 that man casts lots, which were a form of chance equipment like dice, if not dice, but the result comes from God, making Jehovah/Yahweh the literal Random Number God.
** Priests from ancient Israel also used an Ummim and Thummim, which apparently were stones in a bag to be picked in random, for court trials and was controlled by God Himself.
* Three numbers into ''Literature/AMillionRandomDigitsWithOneHundredThousandNormalDeviates'', the fifties' equivalent to a random number generator, and zero has already been repeated twice. Wow, I'm sure it was totally random that this book gave out the lowest number possible when I needed a nine...

* This is such a big thing among pinball fans that they have adopted this term in recent years too as they have intermingled with fans of tabletop games and video games. It is no longer in the same sense as it used to be, however: Whereas older games were full of bumpers, slingshots, and other bouncy things to make the path of the ball unpredictable, more recent machines allow the player greater control of the ball and it is no longer nearly as much of an issue as it used to be. The main issue, now, are [[RandomlyDrops random awards]], benefits given to a player upon fulfilling certain conditions chosen randomly (or pseudo-randomly) from a list. If you're playing, say, ''Pinball/FamilyGuy'', and you really could use an Extra Ball, expect the game to just give you 100 points instead (which is [[PinballScoring ludicrously small]]).
* There is one that continues to persist to this day though: The "house ball," in which the ball, upon launching, falls into the drain without it having gone anywhere near the flippers--in other words, losing a ball with nothing the player could've done to influence it. Recent games where the ball must pass through bumpers after the launch, like ''Pinball/BramStokersDracula'' or ''Pinball/TheWalkingDead'', are particularly vulnerable to this.
* In ''Pinball/KissStern'', shooting the ball into Gene Simmons's head will hold the ball on a magnet on a spinning disk hidden inside his head, then spun and spat back out at the player. Because the ball is spinning, it will take a random and arced path back down. The ball has fallen between the flippers and straight into the drain so often that the game was [[ObviousRulePatch issued a patch a month after it first came out]] that returns the ball back to the player with no penalty if the ball goes down there the next 3 seconds (default setting) after Gene lets go of the ball.
* The central pulsing magnet in ''Pinball/TheAddamsFamily'' causes the ball to get flung in wild and random directions whenever it's active, which happens pretty often.[[note]]It is always active in "Seance," any time a multiball is ready to begin, and continuously throughout all multiballs.[[/note]] It has caused so many tragic moments that it's standard in competitions to physically remove this magnet from the machine.

[[folder:Tabletop Games]]
* In the back of the ''TabletopGame/{{Hackmaster}} 2nd Edition'' rulebook, there's actually a list of various dice rituals that are prescribed for the game, including rubbing the dice clockwise for higher rolls and counter clockwise for lower rolls.
* A number of bizarre good luck superstitions have arisen in the ''TabletopGame/{{Warhammer 40000}}'' community, such as never calling missile launchers by their proper name (it has the word "miss" in it), the idea that painted models are luckier than unpainted models[[note]]Ork players don't count; their paint actually ''does'' change their units' abilities, by the rules.[[/note]], and the practice of occasionally muttering prayers to the Emperor. Never taken seriously, but often endearing.
** Don't ever say "anything but an X." The more important the roll is, the higher the chance that you will get that X. Most players have lost more games by saying "anything but an X" than by bad strategy.[[note]]If you need to say ''some''thing, and good sportsmanship dictates you usually do, saying "2s to [[ChunkySalsaRule squish]]" is usually safe-ish[[/note]]
** Also worth mentioning are the Chaos gods' chosen numbers. Chaos players used to get bonuses for fielding units of a certain size based on which god you were using. Slaanesh was 6, Nurgle 7, Khorne 8, Tzeentch 9, the idea being that the Chaos god makes the characters more lucky as long as they spend time in their chosen number. Modern versions of the game, for the sake of simplicity, have removed this rule.
** The 40K rule book advises players who are rolling large numbers of dice to take out the dice that failed and continue rolling the successful ones[[note]]each bullet is determined by 3 dice: whether it hit, how much damage, and whether the target's armor withstood, so squads with automatic weapons can expect to roll 30+ dice up to three times each[[/note]]. Players will tell you the ''exact opposite'': NEVER reroll the successful ones immediately afterwards, because they have just used up a good roll.
*** A player will say, "I never seem to roll as well as I just did." A statistician will say, "Well, duh. Regression to the mean. You just had a lucky break, so the same entirely random process is very likely to produce a lower value simply because most possible values are lower." Both are correct. The player will usually retort, "Whatever," and produce another fifty dice. 40K players ''always'' have enough dice, just never enough [[MoreDakka dakka]].
** Ork players are advised to use green dice for standard rolls ("green iz best"), red dice for moving through terrain ("coz da red ones go fasta"), and blue dice for critical rolls ("da luckiest"). [[TheHorde Buy in bulk]].
*** A related more-general "rule" is to never roll red dice for armor saves, because they're for killing.
*** And, with Games Workshop occasionally doing promotional faction-specific dice, those are of course, far luckier if you're playing ''that specific faction''.
** It is also recommended, as the melta is one of the most powerful anti-armor weapons a troop can carry, that it never be referred to as such, as firing a melta weapon is an exercise in comedic inaccuracy. Simply referring to which model is firing should suffice. And never use Meltaguns against infantry. They might be great for blowing up tanks, but against infantry you're guaranteed to roll a 1.
** Some Eldar players mutter prayers to Khaine, or to Cegorach if using Harlequins. Chaos players, meanwhile, invoke the Dark Gods, and Ork players just shout "WAAAAAGH" when shooting. Or charging. Or at random intervals.
** The ''TabletopGame/RogueTrader'' spin-off RPG made off with the old idea of the Chaos gods' favored numbers by making 9s occasionally have special effects on rolls - especially those related to psychic powers. Yes, this means that Tzeentch, the god of Sorcery and Change, is implied to be the RNG that is out to get you.
* In the {{Wuxia}} RPG ''WeaponsOfTheGods'', observed good or bad luck with the dice can be utilized as a game effect, discovering that the character is under a curse or blessing which can then be either increased to add actual bonuses or used to create a balancing effect of the opposite type.
** The system itself also features the River mechanic, designed to mitigate the influence of the RNG. You can take dice results out of a role and store them for later use, so if you make an awesome roll on a trivial task, or roll two sets when you only need one, you can set some aside and break them out later when you screw up something important.
* The Red Dragon Inn provides an in depth (and tongue in cheek) tutorial on how to [[http://www.rdinn.com/guild/69/how_to_make_the_dice_roll_high_numbers.html make the dice roll high numbers]].
* Referenced by name in ''TabletopGame/HoylesRulesOfDragonPoker'', where players are afforded infinite mulligans if they've angered the RNG.
* ''TabletopGame/BloodBowl'' features a literal example of this in-universe, in the form of Nuffle, the game's patron god. This trope is also very much in effect for the players, since one of the keys to a successful game is rolling your dice as seldom as possible while forcing your opponent to roll dice as often as possible.

[[folder:Video Games]]
* ''VideoGame/BladeAndSoul'' is infamous for having an evil RNG. Items required for progression randomly drop off of bosses, out of weapon chests, and from giant spinning Wheel Of Fates. Of course you can buy keys from the cash shop that make the item you need come out of a weapon chest. Prepare to go over 100 spins and use over 30 keys trying to get what should logically be a 12.5% chance. Opening 30 without getting the item you need should be an under 2% chance, but it seems more like 25%.
* This concept is taken to extremes in ''VideoGame/KingdomOfLoathing'', where the RNG is a conscious entity that has its own account and frequents the various chat rooms. Those who please the RNG in some way may find themselves "Blessed by the RNG", whereas those who annoy it (especially by begging for a blessing) may find themselves "Cursed by the RNG" (both of which are active character effects). Because [=KoL=] game mechanics rely heavily on random number generation, and because [=KoL=] effects are rarely explicitly defined, there is still a significant debate over whether or not the Blessing and/or Curse actually affect a player's RNG-based "luck" in the game, or if it's just a red herring.
** A player may also be "Blessed by The RNG" by sending a gift package with an 8-ball, and a look in The RNG's display case may reveal other effective sacrifices.
** One particular area that makes players rage to the RNG: the F'c'le. In order to earn Pirate Fledges and be able to access the Obligatory Pirate Cove without wearing fairly weak equipment (the Fledges themselves are actually pretty strong), you must defeat three specific enemy types in this area, pick up their random drops, and use them. Every [=KoL=] player can regale you with stories of spending hundreds of adventures praying for the right enemy to show up, or, alternatively, having all three enemies show up in turn and give up their items in a row. The RNG in the F'c'le is an ''extremely'' fickle godling, and no one can predict its mood on a given day.
* In the {{Roguelike}} communities where [[TropeNamer the term originated]], finding a very good item early in the game is a sure sign that the rest of it is going to be a hellish struggle against the wrath of the RandomNumberGod. It's given you your one good thing, now it's going to do its damnedest to kill you.
** The ultimate item in this is an Amulet of Life Saving, which effectively gives you an extra life (in Roguelikes, if you die, that's normally it -- your ([[SaveGameLimits one]]) save game is erased). If you find one of these early, rest assured the game is going to maneuver you into a situation where even instant resurrection will not help you. After all, if something is tough enough to kill you once, it can probably do it a second time... Paradoxically, "lucky finds" like this that should improve your chances of survival will just make players incredibly paranoid and even ''more'' cautious.
** Added as a character in ''VideoGame/{{TOME}}'' (and its parent game, ''VideoGame/ZAngband''). Random Number Gods are weak, annoying, fast multiplying monsters that drop decent loot -- and cause confusion.
** In Rogue itself the rng has been known to get locked into repeating a number way more often then chance would suggest, causing low percentage events (usually of the unfortunate variety) to happen repeatedly.
* Players of ''VideoGame/MagicTheGatheringOnline'' revere Grog, Goblin Shuffler.
* The RNG manifests in ''VideoGame/BillyVsSNAKEMAN'' as a monster that players in a village (read: clan) can fight. While all other monsters of that class have accurate HitPoints displays, the RNG has nonsensical numbers or words to represent remaining and total life. It also shows up during [[HolidayMode The Festival,]] where it runs a game where you roll ten dice; anything higher than a one gets you an obscenely valuable item. [[CaptainObvious The item cannot be obtained there because you only ever roll ten ones.]] Getting it actually requires completing an entirely different quest.
** Players who have become aware of higher-dimensional spaces may start to briefly encounter the RNG in other locations, and one of the more traumatic experiences during a quest is briefly seeing it in its true form.
* In ''VideoGame/WorldOfWarcraft'', it's customary to use the /roll command a few times before rolling for a specific piece of equipment to please the RandomNumberGod and to get the low numbers "[[YouFailStatisticsForever out of the way]]". In addition, there are persistent (but frequently debunked) rumors that the game seeds the random number generator according to specific criteria, including, but not limited to, the raid leader, the first person entering the dungeon and/or the number of damage-over-time spells ([[http://www.youtube.com/watch?v=HtvIYRrgZ04 more dots!]]) on the boss.
** The developers are equally sadistic with this. Two of the Achievements involved having to get 100 on rolls to Need or Greed loot (once the system was redesigned to distribute loot drops automatically). It can take as long to get those to come up as specific, desperately wanted gear.
* The ''HearthstoneHeroesOfWarcraft'' community has taken to naming their God [=RNGesus=]. With a significant number of cards having [=RNG=]-based effects, many streamers [[https://www.youtube.com/watch?v=ClYoiv338Uk actually ''pray'']] to [=RNGesus=] when they need a random effect to go the way they need. There's also the most random card in the entire game that also happens to be a god. When someone plays Yogg-Saron, for each spell the player played, he'll cast a totally random spell on a totally random target. He can either win the game with a board wipe, a ton of token minions, and/or large heals, or completely throw the game by buffing an enemy minion, make you overdraw cards to the point of Fatigue damage, or Pyroblasting you in the face. Anywhere between turning the game around and throwing a winning game has happened with Yogg-Saron.
* Likewise, there is ''VideoGame/PlantsVsZombiesHeroes'', which is prone to be very evil in RNG. The Super Block Meter is a main factor, as it can favor your opponent while slowly screwing you over to your unworthy death. Need to roll anything but a 1 to block lethal and win? Proc a one and deal with it. You need your opponent to roll anything but a 3 to win? Cue a 3 and get a superpower that will instantly kill you. There are also many RNG related cards such as Seedling, Cornucopia, and conjuring cards, and although they aren't as evil as the Super Block Meter, it may be game changing in your favor or do absolutely nothing. Packs are also a thing, and to add on insult the chances for a super-rare, legendary, or hero is not listed (although it was quickly found that you will get them below 30% of the time). Prepare to spend many multipacks (11 packs) and not get one legendary and get less than 3 super-rares despite being a 10% and 30% chance to get them, respectively.
* VideoGame/FinalFantasyXIV players have adopted the RNGesus meme from Hearthstone. Those who repeatedly fail to win his favour occasionally turn to Lootcifer in hopes of better rolls.
* VideoGame/FinalFantasyXI, however, goes the other direction. as [=RNG=] is the abbreviation for Rangers, some have taken to calling it the Random Number [[YouBastard Bastard]]. For good reasons.
* ''VideoGame/FinalFantasyX:'' On a related note, the patch notes for the 1.01 update of the HD remaster include the intriguing comment "Random number generation is now truly random."
* Anyone who has ever played ''VideoGame/EverQuest'' and attempted to level tradeskills beyond a certain point knows that the RNG is a spiteful beast that hates you. There is a reason the premier crafting forum has the appropriately named [[http://mboards.eqtraders.com/eq/forumdisplay.php?26-Primal-Scream-Room Primal Scream Room...]]
* The ''VideoGame/MonsterHunter'' fandom has come to the conclusion that the series has a sadistic, psychic, "desire-based" RNG for determining how often a really rare item RandomlyDrops, also known as the [[http://www.gamefaqs.com/boards/943655-monster-hunter-tri/54801743 desire sensor]]. It ''will'' skew the odds out of your favor if you really want something, and the only way to end your curse is to not want it. You can't ''act'' like you don't want it, you have to ''actually'' not need it; the system is immune to reverse psychology. So if you spend hours farming the same giant monster for its armor plating, you may go through fifty corpses without seeing one, but you'll end up swimming in the stuff once you give up and move on to a different goal. The only other way to appease it ''may'' be petting the pig.
** The lead designer of the game has officially stated that the desire sensor does not exist, and confirmation bias is the true enemy. He however does admit to questioning the nature of the game at times when even he can't catch a break after 30 back to back hunts.
* Due to the nature of the makers (and fanbase) of ''VideoGame/DragonFable'' the RNG is nicknamed the Rude (or Reall) Nasty Gnome. He sits on a floating pile of all of the gear in the game and throws items at heroes who finish quests. Those heroes that 'amuse' him, get a better item thrown at them (albeit faster).
* One of the main cons in ''VideoGame/DragonBallXenoverse''. Everything that is not the storyline is virtually dictated by the RNG, from the skills you want, to the clothes you wear and even the mentor you want and it even extends to the missions themselves. All missions have bonus objectives that have you fight more or the same enemy twice after clearing the mission quick enough, but even activating the bonus parts is controlled by RNG. That's right, you can literally curbstomp everyone around you with having lost any of your teammates, and you '''still''' will not get the bonus objective, despite fulfilling it. Even worse is when you're trying to get certain items or skills to drop and they simply refuse to, no matter how hard you try.
** The first game was eventually patched to increase RNG odds of both the bonus objective appearing and drop rates, though it was still obnoxious without a doubt. [[VideoGame/DragonBallXenoverse2 The second game]] fixed the bonus objective problem by having it always, without fail, occur so long as the conditions were fulfilled. But the RNG still remains to taunt and flaunt your much-desired drops infront of your face, ''especially'' if it just gives you the shoes or hands part of a costume you really want. And if a drop you're aiming for is in a [[NintendoHard Expert Mission]], expect much agony as you either keep doing drawn-out boss fights just to get what you want, or keep restarting them because [[GameBreakingBug the boss teleported out of the arena and can't get back in, or killed your entire party unavoidably by spamming Gigantic Ki blasts.]]
* Much of the mechanics in ''VideoGame/SummonersWarSkyArena'', but most notably the summoning mechanics, are handled by the [[FanNickname RNGeesus]]. Players have formulated theories on how the system works, how to influence the RNG to grant them that elusive OlympusMons, up to the weird rituals one could do to 'surely' get a natural 4* at least.
* In the ''VideoGame/TheSims'' community, the term "sado-random" (a slightly more accurate form of "pseudo-random") is popular, referring to how even when it doesn't glitch somehow, the game's RNG always manages to give you exactly what you don't want whenever you don't want it. Specific opportunities for unfortunate randomized outcomes vary throughout the series, but the cussedness of the RNG is invariable. For instance, the base odds of a Sim being abducted by aliens are incredibly low, so it'll only happen if they've snuck off to stargaze at the worst possible moment for them to get whisked away by little green men and probed to within an inch of their lives. Likewise, you've got pretty good odds of finding any given job in the newspaper, but if it's exactly the one you're looking for, it always somehow manages to take much, much longer. Fortunately, the cheat console gives you various ways of interfering with most randomized outcomes.
* ''Videogame/FallenLondon'': It plays a huge part, since the entire game is based on stat checks, along with the occasional card that's entirely up to chance. Nothing like raising your scandal to huge, unmanageable levels because you failed an 80% success chance five times in a row. It got so bad the players actually got an ''apology card'' (and a pair of dice as a make-up gift) from the RNG during one of the Christmas events. It's that sort of game.
-->''"We've had our differences. But this is Christmas. Best wishes, the Fallen London [[LampshadeHanging Probably]] Random Number Algorithm."''
* ''VideoGame/FireEmblem'' has plenty of RNG-related stats - during attacks, whether they'll land and\or be a critical hit; during level-ups, what will be improved. And often it screws the player and\or [[TheComputerIsACheatingBastard helps the enemy]], to the point a LetsPlay of ''[[VideoGame/FireEmblemElibe Fuiin No Tsurugi]]'' was named "Let's plumb the depths of the RNG's spite in Fire Emblem: Sword of Seals!"
-->[[http://lparchive.org/Fire-Emblem-Sword-of-Seals/Update%2002/ I do not know what sorcery is at work here, but I'm sure as hell not complaining.]]\\
'''Itís possible the RNG gods were pleased by your previous sacrifice.'''\\
''Or maybe all the levels in my LP are going to start sucking. I think thatís how the RNG works.''
** Fire Emblem is an especially jarring and infuriating series for this trope, due to how many players handle their odds. To most players, anything under 50% is a guaranteed miss, and anything over about 75% is a guaranteed hit. [[note]]In some of the games, the lion's share of which being ones that made it to English-speaking players, this was actually reasonable. Due to a system called "True Hit" by fans, the hit probability display and the actual calculation using different metrics, [[ArtisticLicenseStatistics the latter of which being programmed by someone with a poor grasp of basic math]]. Any deviation either side of 50% actually was exponentially more or less likely than it appeared, with a 75% chance was closer to 90%.[[/note]] When this rule is defied, cue lots of rage and a likely restart because the player wagered an important unit on the odds.
** On the flip side, any enemy unit with a non-zero chance to get a CriticalHit is usually treated like a DemonicSpider, with horror stories of 1% crits being quite easy to find.
** [[WeCannotGoOnWithoutYou Mission-critical characters]] or even entire armies used to get crippled by the RNG repeatedly giving few or no stat increases during level-ups, possibly to the point of [[UnwinnableByMistake wedging an entire playthrough]]. Some mercy was finally applied to the RNG in more recent installments - ''VideoGame/FireEmblemTellius'' onward will re-roll a level that doesn't give at least one stat point[[note]]As of ''Awakening'', which allowed for gleeful abuse of the system, you can still get an empty level if most stats are capped already[[/note]], and ''VideoGame/FireEmblemFates'' further normalizes stats by increasing or decreasing the chance or a stat increasing if it's behind or ahead of average appropriately.
* ''VideoGame/ToukenRanbu'' is highly dependent on this, especially for the crafting of new swords. This means if the RNG is not on your side, you'll never get certain swords unless you commit lots of in-game resources and lots of hours to just make them.
* In ''Franchise/{{Pokemon}}'', the Random Number [[OlympusMons Arceus]] has a habit of trolling you by, for example, giving you critical hits when your opponent is one hit away from fainting anyway. Or when you're trying to catch something and you know your next attack won't make it faint, but a critical hit ''will''. It also [[TheComputerIsACheatingBastard heavily favors the computer]] when it comes to things like accuracy, paralysis, confusion, etc. Enjoy getting hit with Sand Attack once and whiffing your next 3 or 4 attacks, while they can be hit with Sand Attack 5 times ''and'' be paralyzed, but still manage to attack every turn and land them all. Of course, every so often it will decide to ThrowTheDogABone and give ''you'' a ridiculously lucky turn or two. Just so you don't get ''too'' suspicious of it.
** It's even worse when playing competitively. It is rare for RNG to allow either side's schemes to work ideally. Many matches are determined by the number of consecutive turns a paralyzed Pokemon won't move, and finishing off the opponent is often made less trivial by repeated missing from attacks with accuracy upwards of 80%.
** The RNG is also what determines a Pokémon's ability, nature, IVs, and by extent, shininess.[[labelnote:Note]]Shininess is determined by IVs in Generation II, while starting from Generation III it is determined by a complex calculation revolving around the original trainer's ID number, the current trainer's secret ID number (a hidden serial code used to ensure that no two save files are treated alike, as OT ID numbers are able to be identical between trainers), and the Pokémon's personality value (which determines its gender and ability; in Generations III and IV, it also determined its nature).[[/labelnote]] Because of how diverse the range is for all of these (excluding abilities, which are limited to two at most [apart from hidden abilities]), it is very difficult to get a perfect Pokémon for your party. For instance, it is very likely that the shiny Pokémon you just encountered has poor enough stats to serve as nothing more than a trophy, or that Pokémon you found with the ability you want is severely crippled by its IV-altering nature. Conversely, it is possible for a good ability to perfectly compensate for a bad nature, and a shiny Pokémon could be just enough to carry you a long way as a trainer. The fact that [[VideoGame/PokemonXAndY Generation VI]] now includes Super Training and Pokémon Amie, two surefire ways to efficiently EV train your party to GameBreaker status helps alleviate some of the RNG's flaws. [[VideoGame/PokemonSunAndMoon Gen VII]] introduces Hyper Training, which can increase a Level 100 Pokemon's stats to their possible maximum[[note]]It doesn't actually change the Pokemon's IV itself but "flags" it so that the stat is "simulated" as a maximum IV[[/note]]. This and the Ability Capsule (an item that can change the non-hidden ability of a Pokemon with 2 possible abilities) means that the only thing one needs to worry about when it comes to making a competitive monster is its nature and possibly if it has its regular ability(s) or its hidden ability.
** The slot machines have [[https://www.youtube.com/watch?v=u4fjbJnz7O4 surprisingly intricate mechanics]] -- in particular, the chance of winning in the slots depends on the machine's hidden state when you spin, and most of the time the game will stop you from winning anything. In order to either create or avoid a match the game will skip symbols after you press A. This is apparently TruthInTelevision -- Japanese pachislot machines are legally allowed to skip up to four symbols before stopping.
* Don't let its adorable aesthetics fool you, ''VideoGame/AnimalCrossing'''s entire gameplay revolves around randomness. Who your village starts out with, what your native fruit will be, who moves in, who wants to move out, where and what things will spawn, what items will appear in shops... the list goes on and on. After all, real life isn't exactly pre-planned, now is it?
* Items appearing at random times and from random places in the ''VideoGame/SuperSmashBros'' series have caused a lot of resentment and frustration, such that nearly all tournaments, official or not, turn them off. Among high-level players, or at least players for whom Smash Bros. is SeriousBusiness, they loathe the random nature of the items so much that most Smash Bros. {{Game Mod}}s leave items completely untouched, even if the mods might cause them to crash (Brawl Minus is the only high-profile exception), under the assumption that everyone who will play with these mods will never play with items to begin with.
* ''VideoGame/{{Warframe}}'' also holds [=RNGesus=] dear, though a far larger crowd (particularly Vauban players) attempt to invoke [[http://images.akamai.steamusercontent.com/ugc/489020692874195249/2B673445FEAB189A54AAB84B8FD75F694E4E8AF8/ Lootcifer]] instead, claiming Digital Extremes (the devs) are in league with him. Back when Prime items dropped from the Void, there was also frequent talk that the game borrowed the desire sensor from the ''VideoGame/MonsterHunter'' series; if you were hunting for Forma blueprints, it felt like you were almost guaranteed to find only Prime parts, and vice versa.
* The multiplayer mode of ''VideoGame/MassEffect3'' uses a random unlock distribution based on Collectable Card Game style "packs" that contain different characters, items, and boosters. Naturally, players were quick to complain about how annoying it was, especially given that different characters and weapons of the same rarity were very much not equal in usefulness. This is [[LampshadeHanging lampshaded]] by one of the random conversations you can overhear in the Citadel DLC, where an N7 Fury (a biotic that favours light weapons) is arguing with a requisitions officer that keeps trying to give her upgrades to a very heavy shotgun.
* ''VideoGame/MassEffectAndromeda'' uses the same random unlocking system as Mass Effect 3, above, but the in-game monetary reward for completing a mission was reduced, making unlocking rewards even more annoying.
* In ''VideoGame/RedRogue'', a roguelike-platformer, "RNG" is the name of an actual deity within the game that the protagonist has a love/hate relationship with. Altars to RNG are scattered throughout the game, and grant a random effect (positive or negative) when activated.
* Spectacularly ''[[AvertedTrope averted]]'' in the original ''VideoGame/BubbleBobble''. Nearly everything that happens in that game that looks random, from point items to powerups to which [[SpellingBonus E-X-T-E-N-D]] bubbles appear to enemy movement to bubble appearance rates, is secretly controlled by a whole stream of counters and timers. Literally the ''only'' random event is the [[RareRandomDrop hideously rare]] fireball bubble, which is a 1 in 4096 chance from each of the bubbles that appear of their own accord throughout the level.
* In ''VideoGame/Persona3'', if you're unlucky you'll be mercilessly killed by bosses by random chance, i. e., getting Mudo'd by the Intrepid Knight or charmed the whole battle by the 4th full moon boss. At higher difficulties, getting back attacked meant the protagonist getting attacked several times in a row and dying before you can do anything.
* ''VideoGame/BloonsMonkeyCity'' does hold a small amount of [=RNGesus=] with Monkey Knowledge Packs, although because the game is still fairly easily winnable without them, it isn't that huge of an issue. Despite that, expect that the tower you like to use the most will probably be one of the last to level up. Besides Monkey Knowledge Packs, it still revolves on a small bit of randomness at the start, such as the tiles you get at the start of the city and how far Special Missions will be.
* ''VideoGame/XenobladeChronicles2'': Attempts to obtain rare blades are heavily subject to chance, especially since there are 5 different sets of probabilities you might have to deal with in a given save file, and the game doesn't tell you which one you have. The one upside is that if you use up enough cores without getting any rare blades, the game will give you a rare blade out of pity. It only does this three times, though; after that it's just you and the RNG.

* [[http://archive.gamespy.com/comics/dorktower/images/comics/dorktower636.gif This]] ''Webcomic/DorkTower'' strip was the beginning of an arc about scheming dice that started behaving only when the cats got a hold of them.
* Sometimes, the power of the dice can get a little [[http://nodwick.humor.gamespy.com/ffn/index.php?date=2005-06-23 out of control]]. Efforts at appeasing the dice may [[http://nodwick.humor.gamespy.com/ffn/index.php?date=2005-07-12 meet with failure]].
** That was stupid. [[RandomNumberGod They rolled out all the 20s first.]]
** A strip in ''Webcomic/RealLifeComics'' parodies the idea of [=THAC0=] where the main character misses a stationary enemy that wasn't focused on him because he rolled too low to hit it.
* There's a sort of DoubleSubversion to this concept, detailed in the annotations to [[http://www.darthsanddroids.net/episodes/0099.html this]] ''Webcomic/DarthsAndDroids'' strip, which involves "rejecting that superstitious nonsense" and instead using the laws of probability distribution:
## Take 1000 or so 20-sided dice.
## Roll each and every one of them ''once''.
## About one-twentieth of these will have rolled 1s. Take these fifty-odd dice, and roll each of them again, ''once''.
## Two or three of these dice will now have rolled 1 twice in a row. Statistically, the odds of rolling the same number three times on a 20-sided die is 1 in 8000, so now these dice have the 1s "rolled out of them"
## Place them in a special padded container so that they can't roll around, and you may now safely bring them out in emergencies for use for a die roll in which you ''really don't'' want a 1.
** This is of course patent nonsense; no matter how many times in a row you get a 1, the odds of the ''next'' roll getting a one are always 1 in 20, even if it seems "overdue" for a different number. Or the die is weighted to give a lot of 1s.
** ''Webcomic/DarthsAndDroids'' also goes as far as to [[LampshadeHanging Lampshade]] the trope with a link in the annontations of the strip mentioned above that links to this very page.
** [[http://www.darthsanddroids.net/episodes/0195.html This strip]] demonstrates this strategy in action: The prerolled die yields a natural 1 but the RandomNumberGod's true believers don't waver. They reason it will simply be ''even more lucky'' next time.
* ''Webcomic/FullFrontalNerdity'' carries this to a ludicrous extreme when Lewis attempts to dispose of a 'cursed' die that can seemingly only roll 1s. The die rises from the grave and the curse is so strong that every random number generation device in the world becomes incapable of generating any number other than 1.
* {{Lampshade|Hanging}}d [[http://search.dilbert.com/comic/Random%20Number%20Generator in this]] ComicStrip/{{Dilbert}} comic strip when he's touring a layer of hell known as Accounting.
* In the ''{{Webcomic/Erfworld}}'' comic intermission, a Luckamancer [[DiscussedTrope discusses]] the [[http://www.erfworld.com/2011/11/inner-peace-through-superior-firepower-%E2%80%93-episode-008/ mechanics behind luck-manipulation]] with a young Wanda :
-->''"Now here's an important thing, though," said Clay, pointing at the die. "Where did those 4s come from?"''
-->''Wanda looked down at the little brown enchanted pyramid and shook her head. "From you. You cast upon the die."''
-->''Clay grinned slyly. "So you're saying my juice had a physical effect on the way the die rolled."''
-->''"Yes and ''no''," said Clay, grinning more broadly now. "It's not a direct effect, you see? The 4 is a Number. It had to come from somewhere."''
* In ''Webcomic/LarryLeadhead'', the God appears as capriciously as you might expect. Larry's dice rolls are renowned, for all the wrong reasons.


[[folder:Web Originals]]
* A Website/CollegeHumor sketch about VideoGame/{{Tetris}} called "[[http://www.collegehumor.com/video/5767906/the-tetris-god The Tetris God]]" involves the eponymous character manually choosing which piece will be next.
--> ''"Thou art a '''cruel''' and '''angry God!!"'''''\\
'''''"LINE PIECE!"'''''
* Ribbon of ''/[[Website/FourChan tg]]/ [[http://1d4chan.org/wiki/Ribbon#.2Ftg.2F_Explained explained]]'' series [[http://1d4chan.org/wiki/File:Tge51.jpg explains]].
* Often invoked on ''WebVideo/{{Tabletop}}''. In the ''Elder Sign'' episode, Creator/WilWheaton claims that the dice are trying to kill him. [[spoiler:They succeed.]]
* ''WebVideo/CriticalRole'' is...strange. On the one hand, it's a livestreamed D&D game, so absolutely nothing is staged. Chance should be king. And yet sometimes the dice seem to obey the TheoryOfNarrativeCausality in that players are prone to getting [[CriticalHit Natural 20s]] at the ''best possible times''. Examples include Percy rolling a crit to maintain concentration on his Hex against his arch-nemesis, Dr. Ripley; Grog ''killing'' [[spoiler: Kevdak, his uncle]], with a life-or-death critical hit; and Vex rolling two crits in a row when Vax is [[spoiler: knocked unconscious by the Briarwoods]]. The dice even believe in TrueLovesKiss, apparently - when Vex kisses [[spoiler: Percy during his resurrection ritual]], she rolls a Natural 20 on her persuasion check to [[spoiler: help convince his soul to return]]. On the other hand, Creator/WilWheaton has a brief guest spot, and maintains his streak of absolutely miserable luck known as "the Wheaton dice curse", rolling five or less an ''absurd'' number of times.
** Even their failures are oddly appropriate for the narrative! In Whitestone, the lingering undead atmosphere causes the entire party to need to make saves against "corruption" once a day. The only person who has failed the saves so far is Percy, who is ''already'' acting more violent and being corrupted by the smoky entity from his dream. (It helps that Mercer is an excellent storyteller and readily makes the die rolls make sense). Similarly, Kaylie [[spoiler: Shorthalt]] has a perfect opportunity to attack Scanlan and rolls a 1, as if she can't bring herself to [[spoiler: stab her own father]].
* In ''Literature/TalesOfMU'', Glory and Mack {{discuss|edTrope}} the possibility of whether or not there's a god of magic, which leads to describing said god as using dice, complete with a spin on Albert Einstein's quote "God does not play dice with the universe."
* In ''WebVideo/PowerRangersHyperforce'', it has become a running theme that the Rangers usually cannot perform even the most basic actions as their die rolls are terrible. They often need to rely on using multiple "Supers" (which grant +2 on the roll each) to succeed.

[[folder:Real Life]]
* There are some calculations scientists perform that require truly random numbers, such that the slight predictability inherent in a computerized system is too large. For these cases a "True Random Number" generator can be purchased, which is effectively a small radio telescope tuned precisely to the frequency of the Cosmic Microwave Background radiation, as produced by the Big Bang.
** [[http://www.fourmilab.ch/hotbits/ Radioactive isotopes]] can also be used - set up a Geiger counter and a numeric counter, then stop the counter whenever the Geiger meter goes "beep". The time between successive radioactive decays is random, so your numbers are random.
** Noisy diodes are also truly random, and as a benefit for computers, binary. Similarly, overdriving a transistor into overheating so you can read thermal noise from it.
** http://www.random.org/ generates random numbers using atmospheric noise.
** For many microcontrollers, reading an input off an analog-capable pin that is "floating" (not connected to anything) will return a truly random result as the pin will (or won't!) respond to electronic noise, the actions of other pins on the chip or other things in the local environment. This random result can then be used as a seed for a pseudo-random number generator.
** Actually getting a random number out of a truly random source is far from trivial in itself - you have to build a device that doesn't introduce any bias.
** Technical note: The above random events may not have the ''distribution'' you need (many different exist) but converting them is fairly standard textbook math.
* As [[https://www.youtube.com/watch?v=MRzg_M8pQms this 2015]] video explains, cheap dice have dull edges because they were polished in a rock tumbler. The resulting imperfections change the die's center of gravity and make it easier to roll over some edges than others. So there is a scientific explanation to this phenomenon, and a way to prevent it.
** It also makes reference to one of the classic ways con artists can rig games: "shaving" the edges on a die (usually a casino die, since they have sharp edges to begin with). You trim off a tiny bit on the edges of whatever's opposite the side you don't want to land on. So for example, if you don't want to roll a six, you'd shave the edges of the one face. The die expends less energy rolling over the shaved edges, which skews the probability ''way'' below 1/6. (Incidentally, if you find an ''actual'' casino die that's been shaved, you could be rewarded by the state gaming commission. [[SeriousBusiness They take fair odds seriously.]] Outside of a casino, though... just remember the page quote.)
** Another common method of messing with die odds is to cook them. You take your plastic die, put it in the microwave with the side you want to show face up, then nuke it for a couple of seconds, no more than five. The nuking causes the plastic to melt downwards a bit(thus making the die more likely to stop on that edge, since it's heavier). Done right, it's almost undetectable at casual inspection.
* Most computer software use a [[http://en.wikipedia.org/wiki/Pseudo_random_number_generator Pseudo random number generator]] Often, a programming language's library will provide it, but for early games and applications, bugs in the implementations of pseudo random number generators caused biases. C's built-in random library is actually notable for allowing programmers to use it incorrectly and introduce biases to the numbers generated by it. Problems with how the random number seed is picked can also cause the numbers to be predictable.
** In the [[ToolAssistedSpeedrun TAS]] community, it's common to reverse engineer a video game to find what algorithm is used to generate random numbers, and even more importantly, where the game gets the values it uses to seed the generator. Once all this is known, it often becomes possible for them to use their capacity for inhumanly precise controller input to [[DidYouJustPunchOutCthulhu bend the Random Number God to their will]], forcing unbelievable strings of good luck.
** Since random number generators are used by many security applications, their predictability can lead to [[http://en.wikipedia.org/wiki/Random_number_generator_attack serious security vulnerabilities]]. Which makes computing with serious security need another area of use for the aforementioned true random number generator devices.
** It is difficult to keep correct uniform distribution when picking more complicated random events, even while the actual random number generator has a good distribution. For example, consider picking a random point inside a disk, as is needed in certain games (usually some variation of bullet spread). Programmers without prior knowledge, specially amateur ones coding for a game mod can implement this random point generator in a way that there is [[http://mathworld.wolfram.com/DiskPointPicking.html a bias towards the center of the circle or towards its limits]].
** One particularly notable random number generator, known nowdays as RANDU, was noted as being, in the words of Donald Knuth, "truly horrible". It has since become a textbook example of a bad PRNG, due to many, many undesirable properties. [[note]] Among the lesser sins: only generating odd numbers if fed an odd seed value, and even numbers if fed an even seed value. Given that most programs feed the result in as the next seed to ensure consistency across runs, this is not a trivial problem. And that's one of the ''lesser'' obvious problems with RANDU; things can get even worse from there.[[/note]] (On the plus side, if your system is newer than the second half of the Reagan administration, it's highly unlikely you will suffer under this particular misguided PRNG.)
---> [On RANDU]: "One of us recalls producing a 'random' plot with only 11 planes, and being told by his computer center's programming consultant that he had misused the random number generator: '''"We guarantee that each number is random individually, but we donít guarantee that more than one of them is random."''' Figure that out."
** Many versions of Linux have a very good PRNG as a system resource with a seed that depends on many hard-to-access and fast-changing internals of the system, making it difficult to guess what the next value will be, even if you have many recent values and normal programmatic access to the system.
** Seeding and reliable replication of random number strings isn't always a bad thing. Many games that utilize RNG in world creation have the ability to recreate the same world by inputting the same seed and parameters. (Dwarf Fortress is famous for this).
* Apple rewrote the "Shuffle" program on their newer iPods so that no two songs from the same artist are close to each other, if possible. Turns out people want ''high'' entropy from a shuffle, not ''random'' entropy.
* [[UsefulNotes/QuantumPhysics Quantum Tunneling]] can be [[QuantumMechanicsCanDoAnything at the bottom end of everything]]. Atoms, or at least parts of it, can be automatically displaced anywhere, anytime and at any size, and this happens constantly. This ensures that there is no ''absolute'' zero or one-hundred percent chance that an instance of an object is bound to happen. Some theorize that an EarthShatteringKaboom could happen in [[ParanoiaFuel an instance Quantum Tunneling occurs]].
** You'd think rolling a ball from a shorter hill to another taller one is never going to happen. In that instance, the ball may actually get there with an impossibly small chance that an atom of it is displaced somewhere.
** The same effects can also happen in a computer, where electrons in a circuit are randomly displaced no matter how heavily systematized the connections may be, thus glitching occurs.