* ''Franchise/{{Ultima}}'':
** In the original games, Lord British, [[LordBritishPostulate supposedly invulnerable]], can be killed by (for instance) [[http://www.computerandvideogames.com/article.php?id=181917 packing his throne room with kegs of gunpowder and throwing a fireball]].
** One of the programmers for several of the ''Ultima'' games, Mike [=McShaffry=], in his book "Game Coding Complete" mentions a bug which caused a spell to produce a wall of fire. They then decided they liked this and decided to leave it in.
** ''VideoGame/UltimaVIIPartII: Serpent Isle'' had a copious amount of bugs, due to the rushed completion. The most noteworthy ones are the "False Coin" spell, which is supposed to make illusionary money but fails at the "illusionary" part, "Vibrate" which doesn't do damage but makes people drop ''all'' their possessions (including some things they're not ''supposed'' to drop) and "Serpent Bond", which allows you to bypass script triggers. This can be used to, among other things, carry stuff out of a dream, and save a temporary party member from his scripted death.
** Its predeccessor, ''VideoGame/UltimaVII: The Black Gate'', was also full of bugs, and one of the more useful ones involved Batlin's delivery request in Britain. With the right usage of declining his request, accepting his request, and dumping part of your inventory, you could repeatably gain 100 EXP and dupe any item of yours that can stack.
** ''VideoGame/UltimaVII: The Black Gate'' also had diapers. As, apparently, a joke item, they made enemies repelled by dirty diapers. Then the programmers forgot to make any creature ''resistant'' to diaper-repulsion, with the result that a pile of dirty diapers is one of the most [[LethalJokeItem effective weapons in the game]].
** ''VideoGame/UltimaOnline'' had a rather famous incident of "it's not a bug it's a feature". A "creative use of magic" allowed someone to loot people's houses. Essentially robbing someone of all of their stored possessions.
*** In the beta Lord British came onto the server himself to talk to players about a recent crash. Unbeknown to him, the crash had turned off his "Invincible" tag. Some player spontaneously decided to cast a fire spell on him as a joke. So spontaneously, in fact, that he had to steal the scroll from someone watching the speech. He wound up assassinating Lord British in full view of everyone. Note that the guy that did this had ''no clue'' that LB had lost his invulnerability.\\
\\
As bizarre as it may sound for what would now be considered a simple act of PVP on a dev who didn't realize his power was turned off, at the time this was a BIG HUGE DEAL. There were articles about this event in mainstream PC gamer magazines, interviews with the perp in question ('Aquaman') and more - it turned into a huge debate over [=PK-ing=], the act of 'Player Killing', whether or not it was fair and what could be done about it. The article in PC Gamer magazine itself treated [=PKing=] as a threat to the average gamer and something that could turn people away from this relatively new genre of game. Re-reading these old articles is exactly as quaint as you'd imagine, proto-MMO'ers 'discussing' (read: arguing bitterly over) what could be done about what would eventually become one of the largest draws to the MMO market, PVP.
*** Once upon a time there were a lot of item duplication bugs in UltimaOnline, that could dupe all kinds of things, like scrolls that cast a magic arrow for 1 pt of damage. There were also slimes that would split in half every time they took damage. One enterprising player wrote up a script, barricaded himself behind some boxes, and promptly crashed the server.
** The [[ObviousBeta steaming pile of code]] known as ''VideoGame/UltimaIX'' had more than few bugs and glitches that turned out for the benefit of the player:
*** You can save the hardest-to-find spell components from being consumed simply by dragging them back into your inventory after the text box pops up to input the name of the spell. The same piece of nightshade for every spell that needs it? You bet!
*** A few of the bosses could be targeted and killed with ranged weapons before their scripted cutscenes kicked in. They wouldn't move to defend themselves, and after they were killed you could trigger the cutscene and it would go off as scripted -- minus the boss.
*** The dungeon Wrong would take away all your items if you were caught by the guards. You could easily get them back once you knew where they were stored, but if you had filled all of your available inventory slots (anything would do) the game would put your original items in a bag for you. The key here being that bags are extremely rare (without the 'economy' patch which actually gives you something to ''do'' with the piles of gold you invariably leave scattered around), giving you nine slots for the price of one. This bug could be repeated until your backpack was filled with bags.
*** Stacking "bridges": With a [[UselessUsefulSpell Level 0 spell]], a little ingenuity, and a lot of grabbing everything that's not nailed down, you could make items literally float in midair and due to the mechanics of the game, you could hoist yourself up onto them. Given enough time and effort (but still far less than getting there normally) you could access parts of the game that normally wouldn't be arrived at until much later.
*** Since every item in the game, even money, was a physical object, sometimes they would clip out of whatever they were stored in. One chest in particular had a piece of the best armor in the game that could only be unlocked with a key gained by starting the game as one particular class. But find the right patch of pixels and it was yours for the taking anyway.
*** Pulling out a Glass Sword in the Buccaneer's Den armor and weapons shop would make the glass of the display cases disappear, giving you access to some really good gear that you weren't supposed to get.
*** Four words: Infinite Mana Stat Boost.
** [[http://www.it-he.org/ultima.htm This fellow has the majority of his website devoted to making Ultima games do things they aren't supposed to.]]
* ''VideoGame/DarkSouls'' Pre 1.04 had a pretty crazy exploit that involved the Dragon Stone you get for joining the path of dragons covenant that could net you infinite souls and humanity while using it.
** Some bugs carries over, including the very useful Bottomless Box Glitch, transferring any items, including plot-relevant ones to a freshly-starting character, allowing them to roll (literally) with fully upgraded items. This makes for a tremendous benefit to returning players who want to get their leveling from the get go immediately and stat their perfect build from early on, but also of a boon for Griefers to invade other people at extremely low levels.
* ''StarControl 2'' had the infamous "planet-lander" bug: In the original version, selling your planet-lander when you had none to sell would cause an underflow bug, leaving you with around two million or so planet landers, that you could then sell for cash.
* ''VideoGame/TheElderScrollsIIIMorrowind'' has a bug with alchemy that can quickly prove to be a gamebreaker, on two fronts. First, while simple alchemy ingredients are available in unlimited supply for 1 gold each, the potion created by combining two of these ingredients with alchemy sells for substantially more than 2 gold, making for a source of unlimited money right from the start of the game. Second, the potency of potions is partially based on your intelligence score, which can be boosted by an effect called Fortify Intelligence... and it just so happens that you can find the ingredients to make Fortify Intelligence potions in unlimited supply in the first major city you reach in the game. By creating potions, drinking them, and creating more potions, the player could easily create potions of horrifying power (boosting statistics by tens of thousands of points, or restoring thousands of points of health per second for literally days) within minutes of starting the game. Combined with the first alchemy bug, the money needed to buy these ingredients was no object... the free master alchemy set lying around for the taking in the mage's guild of another town only made it easier.
** Another bug often combined with the one above was selling items to a merchant with a negative quantity. Merchants designated in the editor with a negative quantity for an item would regenerate that number after you left the dialogue box. So a merchant with -20 Muck Root always had 20 Muck Root when you re-entered the menu. The trick is that if you sell that item to them, it would instead create an even more negative quantity. So, with the above, if you bought the 20 Muck Root, exited, then re-entered and sold them the 20, they'd then have 40 to sell every time you entered the menu and so on. Thus, you had an infinite supply of any item that started with a negative value. One of the primary uses was stacking common potion ingredients to grind your alchemy skill.
** By 'juggling' weapons that grant stat bonuses, it's possible to have the effect stack with itself and render you nigh-godlike. This allows you to complete the game in a [[http://speeddemosarchive.com/Morrowind.html matter of minutes]].
** The hero could shoot arrows through closed doors to overcome staggering odds.
** Alternatively, once you owned the spell Soul Trap, (or a piece of equipment that would cast it,) and a spell to fortify an attribute, you could create a spell to fortify your strength/speed/intelligence etc. for one second and then soul trap yourself to permanently apply the fortification. Doing so could allow you to increase your attributes, skills, etc far beyond the scope the game would normally allow, and make it so you could jump over Red Mountain or cross Vvardenfell on foot in a matter of minutes.
*** This works with spells other than fortify attribute, as well. Combining it with a spell to summon a golden saint, for instance, will summon a ''permanent'' golden saint to run around with. This can be done multiple times, to either slaughter them and take their gear or to stomp around followed by an army.
** Another endless gold trick involves selling gold pieces to merchants. Clicking the gold to sell it one piece at a time, then taking it all back at once, will result in the merchant buying it for face value then giving it back at a bulk discount. You can't have a transaction without buying or selling anything, though, so the end result can be selling one gold piece for as much as you have the patience for.
* ''VideoGame/TheElderScrollsIVOblivion''
** A bug lets you duplicate any object hundreds of times. Cue [[http://www.youtube.com/watch?v=hmszTpK54Mk Youtube videos]] of players flooding cities knee-deep in watermelons and human hearts.
** Make two copies of an enchanted wearable item. Equip one copy. Duplicate the unworn one. Both fall off, but the effect remains. Change clothing on another body part to make it permanent. Stack enchants to your heart's content. Alternatively, just be wearing enchanted items during one of the few moments where the game forcibly removes your gear.
** Also: paintbrushes aren't affected by gravity, allowing you to construct stairways, sniper's nests, and so forth out of dropped art supplies.
** Let us not forget the fact that enchanting enough armor pieces and accessories with chameleon effects [[GameBreaker turns the wearer permanently invisible]]. Hilariously, people could see you fine in town... even if the player couldn't. These same people would not notice you if they then went outside the town gates and you stabbed them with a broadsword.
** There's also the hilarious physics of jumping off items you're holding below you in mid-air, which makes for some great speedrunning tactics.
** ''Oblivion'' has magic spells that spawn enchanted ("bound") armor and weapons. They have very strong attributes and zero weight, but the game balances this by making them only last for a while - then the spell wears off and they disappear. But if you let the item get damaged, repair it and then drop it, it won't vanish when the spell wears off. You could then pick it back up and have it [[GameBreaker permanently in your inventory]].
** If you attack a guard in the Arcane University, occasionally every NPC in the University will break out into a full-on brawl.
** And then there is the famous door physics glitch. If you drag a body into a doorway and then shut the door in just the right way, the door will close and the body will get stuck in it. The collision detection goes crazy and results in a [[http://www.youtube.com/watch?v=3EyFURUovb4 flailing corpse stuck in a door or wall.]]
** If you are suspended from the Mages' Guild, you are required to gather alchemic ingredients for Raminus Polus to get back in[[note]] 20 Dragon's Tongues and 20 Redwort Flowers for theft, 20 Vampire Dusts and 20 Daedra Hearts for murder[[/note]]. If it's your first offense, a glitch allows you to get back in if you collect 20 pieces of only one of the required items.
* ''[[VideoGame/TheElderScrollsVSkyrim Skyrim]]'' wasn't out for even a week before people found out that, due to how the new game engine handles eyesight, you could put buckets on people's heads and they won't see you stealing.
** Realism at its finest. If they could figure out how to take off the buckets, it would be nice though.
*** According to Todd Howard, they learned about the bug the day after release. The lead programmer wanted to fix it but Howard insisted it [[ThrowItIn be left in]].
** Due to a bug in the physics engine, getting killed by a giant's club will [[http://www.youtube.com/watch?v=Oso_mmhvm-Y&feature=related launch you a few miles into the sky]]
*** This bug is inherent to the physics of the Gamebryo Engine ([[BlatantLies which Skyrim's engine is not at all based on]]) and has showed up (much less frequently) in previous games using it. Conditions that mimic the attack of a giant's club are just much rarer, but can be obtained by kicking downed bodies with weapons with lots of kickback (like the ballistic fist from ''VideoGame/FalloutNewVegas'').
*** This bug comes from the fact that the game's physics engine uses a momentum point system on a ratio to that damage of an attack. So when that giant hits you with its club (which is a one or two hit kill), it deals its damage to you and, should you die, it converts the extra damage to momentum points on your corpse (the more points the farther you fly) which is why you tend to just fall down if it's a late game one-hit kill but go flying if it's a late two or an early two (you can try this yourself by having a weapon capable of massive damage like a hammer with a high fortify strength and using it to hit a wounded opponent).
*** While the giant's club is specifically an item, it's also flagged so your character cannot pick it up and wield it. Your followers, however, do not have this restriction. Thus, it's sometimes possible to order your follower to pick up a club, meaning you get to see Lydia beating people with a massive bone bigger than she is.
** Due to another physics bug, riding your horse onto the head of the dragon from above has... [[http://www.youtube.com/watch?v=u9QbWhL6cD8 interesting effects.]]
** Casting a fireball on a dead dragon skeleton will toss it around like a toy. If you do it on top of a mountain, it will fly further than the console's draw distance.
** For some reason the Jagged Crown never counts as headgear and sometimes wants to count as a shirt.
** Potions of Fortify Restoration increase the power of restoration spells and effects. This includes potions and (clothing/armor) enchantments. You can enchant equipment with Fortify Alchemy, which will also be effected by the potions, allowing you to make more powerful Fortify Restoration potions, boosting your Fortify Alchemy Enchantments(though you have to unequip them and put them back on after each potion for it to take effect); repeat ad infinitum. This eventually leading to potions and equipment that bestow billions of hit points, let you Shout without cooldown, or [[ColossalCaveAdventure kill a dragon with your bare hands]].
** Completing the Daedra quest "Discerning the Transmundane" earns you the Daedric Artifact "Oghma Infinium", a tome that boosts all skills in one of three classes (Warrior, Mage or Thief) by five points. However, the downside to using said tome is it will disappear after first use. This can be avoided by exploiting a glitch involving [[ItMakesSenseInContext a bookshelf and careful hand coordination]], allowing you to [[GameBreaker boost all skills over time]] and reach level 81 [[DiscOneNuke before even making it through 1/8 of the main quest]].
*** This has reportedly been fixed in patch 1.9.
** It's not particularly useful that sometimes mannequins animate and might walk and follow you around. But the scare it gives you sure is fun.
** One of the biggest complaints about the 1.9 patch is that it removes a glitch that would occasionally cause the courier to show up [[NakedFirstImpression wearing only a hat]].
* In ''VideoGame/FinalFantasyI'', the creators accidentally had a four-square peninsula on the world map belong to the wrong monster area, making the enemies there be much more powerful than the ones normally fought at that point in the game. The "[[PeninsulaOfPowerLeveling Peninsula of Power]]" was popular enough for power-leveling that it has stayed in the remakes, and inspired similar high-powered monster hideaways in subsequent ''Final Fantasy'' installments.
** Also, in the PSP remake, with the glitch described [[http://www.gamefaqs.com/psp/937909-final-fantasy-anniversary-edition/faqs/50991 here]], one can turn low-level equips into top-tier equipment, as well as equipping items on classes that shouldn't be able to use them, such as the Barbarian Sword, the strongest weapon in the game equipped on the WhiteMage.
* There is an item duplication bug in ''VideoGame/FinalFantasyIII'' for the [[VideoGameRemake Nintendo DS]]. On the one hand, finding Phoenix Downs (which revive fallen characters) is extremely rare and there exists a limited amount of them in treasure chests, making each and every one a precious resource; on the other hand, being able to duplicate them at will can annihilate the game's natural difficulty.
** Plus, rather early in the game (before the second dungeon or so), you find one elixir. What you are supposed to do with it is give it to a sick NPC in the town you find it in, and you get a rather impressive stash of treasure for giving it up. You won't find another for at least 3 dungeons, and even then, there are only 20 guaranteed in the game. It completely ruins any game difficulty, as that one elixir will last you for a long, long time.
** The original Japanese version of ''Final Fantasy III'' has some wonderful glitches, like the [[http://tasvideos.org/GameResources/NES/FinalFantasy3.html item upgrade glitch]] that exploits an inventory stacking overflow error to alter the types of items, making it very easy to obtain most of the Onion equipment.
* ''VideoGame/FinalFantasyIV'' allowed you to duplicate anything that could be equipped on the left or right hand through an equip glitch, even items that could only be obtained once in a regular play through. This was incredibly handy for dual-wield characters and gave Edge many more weapons to Dart (multiple copies of the Excalibur sword, for example). You could also sell the more valuable dupes for tons of GP, turn around and stock up on other items in shops, which was especially useful when trying to purchase high priced items like Ethers and Elixirs. It was also possible to equip a shield on Rosa and Rydia, substantially increasing their staying power. This prevents Rosa from using a bow and arrow, but the "Life" staff works fine. This only works with the SNES and PlayStation versions though, not the GBA port or DS remake.
** The Crystal Room Warp Trick from ''VideoGame/FinalFantasyIV'' for the [[SuperNintendoEntertainmentSystem SNES]], which allowed the party to skip the [[ScrappyLevel Sealed Cave]] entirely. Unfortunately, it was removed from subsequent rereleases and remakes.
* ''VideoGame/FinalFantasyVI'':
** Relm Sketch Glitch: Using Relm's sketch command under certain conditions might erase your game... or it could max your hitpoints to 9999, fill your inventory with secret items and turn Edgar into the fallen hero [[spoiler: Leo]]. While the glitch is potentially dangerous, the conditions to trigger a given result are also predictable enough to be safely exploited if you know what you're doing. The short version on why it works the way it does is more or less detailed in the intro paragraph of this trope, and later releases of the game fixed this glitch.
** The evade stat never actually gets used for physical attacks, like it's supposed to. Instead, evasion to ''everything'' evadable in the game (which includes the vast majority of spells) is ruled by the m-block statistic, and it is possible to max out this stat, making the character NighInvulnerable. This has an interesting consequence for the game's "Dark" status, which blinds a character; it effectively raises the enemy's Evade when that character attacks; this has no effect whatsoever, due to the bug! There's also an item called "Goggles," whose only effect is to prevent the "Dark" status, so of course, the GogglesDoNothing. This is fixed in the Game Boy Advance remake. The Dark status effect does have one negative effect: it prevents Strago from learning any Lore spells while he has it.
** The Psycho Cyan glitch causes Cyan to launch physical attacks non-stop--not allowing anyone else to move--until all enemies are dead. It's a bit of a pain to set up, but is plenty entertaining if successful and a huge help to players attempting {{Low Level Run}}s. [[http://www.youtube.com/watch?v=vt9YmtT5PC0 Here's a demonstration.]]
*** [-To explain what's going on: First you have Cyan use his second Swordtech/Bushido art, Retort. This puts him in a status where any normal attack on him will cause a counterattack against the enemy. Then, you turn him into an imp, which causes most of his techniques to become unusable -- but does not take him out of Retort status. Then you kill him with a non-physical attack, such as a powerful spell or Doom. When he's dead, if he still wasn't attacked and did not act, he's still in Retort status, and now the computer isn't keeping track of what target needs to be hit to set off the effect. Then you revive him, and attack with anyone -- or wait for the enemy to attack. Cyan will counter the mere fact that an attack was made, using a normal attack of his own (as he's an Imp), and ''will counter his own counters indefinitely.'' Well, until the enemy is dead, anyhow.-]
** Vanish/Doom: Casting vanish on anything will remove its magic evasion (which is normal), but this means that [[UselessUsefulSpell instant death]] spells '''[[GameBreaker will always hit]]'''. Even against bosses that are normally immune.[[hottip:* :This is because the coding that says "If target is under Clear status, and attack is magic-based, attack hits" takes priority over "If target is immune to instant death, and attack causes ID, attack misses"; the GBA version reversed that.]] The only monsters that can't be killed in two spells are the ones immune to Vanish (of which there are few, because Vanish is supposed to be a ''positive'' status ailment) and undead enemies (since Doom ''heals'' them; they're already dead after all). In the case of undead, though, you can just cast X-Zone instead; since it tosses them into another dimension rather than killing them, already being dead provides no protection. This only applies to instant death spells (and revival spells, which are usually not worth the effort), and fixed in the Game Boy Advance half-remake (though it still works on monsters NOT immune to instant death normally, this is expected and far less game-breaking).
** The original Japanese version also included a glitch that let you equip absolutely ''anything'' as a helmet. The best helmet in the game? A drill.
*** And they knew it too(eventually)! It got referenced in [[DissidiaFinalFantasy Dissidia]] with the "Machine" armor set!
** When Setzer suggests marriage to Celes as his win condition on the coin toss, Celes blushes. However, Edgar and Sabin share the same colour palette, and blush too. It's cute.
** A couple of nifty Slot glitches: Strago can learn L5 Doom from 7-7-7 Joker Doom, and, by muddling and unmuddling Setzer, 7-7-Bar Joker Doom, ordinarily a TotalPartyKill, can be reversed onto enemies (including ones which outright prevent a 7-7-7 Joker Doom, such as the very final boss).
** The Rippler spell, one of Strago's possible Lores, allows the user to trade status effects with the target. Normally, one would assume this means the StandardStatusEffects and [[StatusBuff Status Buffs]]; however, it also includes things such as Gau's Rage, Mog's Dance, and Shadow's dog. With some Rippler maneuvering, Interceptor can be set (permanently) to guard whatever character the player decides needs the protection, instead of guarding Shadow.
*** However, if an enemy uses Rippler on Shadow and the enemy dies, Interceptor goes with it and the dog is LostForever. Oops!
** Sabin being able to [[http://www.youtube.com/watch?v=2u84cH_bmTA suplex a train]] comes to mind. Sure, it's a once-per-game experience, but seeing him throw a locomotive into the air and slam it back on its rails is both [[CrowningMomentOfAwesome awesome]] ''and'' [[CrowningMomentOfFunny hilarious]].
*** For even more hilarity, if you use Suplex but Sabin gets hit with Confusion before he can use the move, he can suplex ''himself.'' [[http://www.youtube.com/watch?v=_zExDUoaZPo A video of this]]
** Wind God Gau. Gau isn't supposed to be able to equip weapons, but in the original SNES version, he could equip the Merit Award, which allows any character to equip certain weapons and armor. In this case, give Gau one of Cyan's swords, the Kazekiri (Tempest), which randomly casts Wind Slash 50% of the time. Then give Gau the Master's Scroll (Offering) relic, which allows him to attack four times, and use the Stray Cat Rage and hope he uses Cat Scratch, which does quadruple damage. If you're lucky, Gau will attack four times at quadruple damage and use the Razor Wind after each strike. Later releases of the game remove Gau's ability to equip the Merit Award, but the technique ''could'' still be utilized by Gogo in the PlayStation port, until the Game Boy Advance port phased out the Wind God altogether by barring Gau and Gogo from using the Merit Award relic.
* ''VideoGame/FinalFantasyVII'' had the W-Item materia. It allowed you to use two items in one turn, but due to a glitch also allowed you to create infinite copies of any item usable in battle. Including rare items, expensive items that could be sold to shops for loads of gil, items you're only ever supposed to get one of, and items that are {{Game Breaker}}s in their own right when available in mass quantities. Done improperly, though, this can also result in ''losing'' items.
** By endlessly copying Elixirs you can spam them on Magic Pots, which drop the most EXP and AP in the game, thus allowing you to break the game even further
** Abusing this glitch greatly speeds up the chocobo breeding quest by replicating an otherwise ''very'' expensive item that is basically a chocobo steroid. Just for fun, stuffing the final gold chocobo (the offspring of similarly suped up birds) will give you a golden feathery ''[[PhysicalGod god]]'' as far as racing goes.
** Also; the "Quadra Magic Glitch", which lets you get the Quadra Magic materia without doing any chocobo breeding. [[http://www.youtube.com/watch?v=vhDDj_b1hek&feature=related See here]].
** Vincent's final weapon increases in power the more enemies Vincent kills, up to a {{cap}}. However, if you kill a ridiculous number of enemies (around 65535) with him, the damage formula for the weapon overflows, which triggers a failsafe script (possibly so that Vincent doesn't end up healing his enemies with the weapon, making it useless) that forces any target hit by the weapon to die instantly. Yes, even [[BonusBoss Emerald Weapon and Ruby Weapon]].
** The Turbo MP materia which increases both damage output and MP cost by up to 50%, also has a cap bug that prevents the MP cost for growing above 255, making it cheaper for anything that cost more than 170MP: Such as Knights of the Round Table, 250MP, which coupled with Turbo MP costs only 255MP instead of 375.
** Not nearly as well known: Under normal circumstances, it's not possible to use the support materias HP Absorb, MP Absorb, Added Cut, or Steal As Well with either the Slash All or Double Cut command materias. It is however possible to put any of those four support materia in a pair of linked slots with Master Command; if you also have Slash All or Double Cut equipped, the benefits of the support materia will be added to them as well.
** Want to heal your party to full-health in the middle of battle? Cast Regen on the party, then pop the lid on your Playstation open, then have someone in your party cast a magic spell. The whole battle will grind to a halt until you close the cover, but Regen heals your party in real-time, so you can wait out your injuries before resuming. Later entries in the series, such as ''VideoGame/FinalFantasyIX'', prevented this by pausing the game if the cover is opened, but you could still use Regen and cast a summon spell with an [[OverlyLongFightingAnimation impossibly long attack animation]] for a similar effect.
* In ''FinalFantasyIX'', adding Auto-Haste and Auto-Regen, and some other things, you can effectively have Auto-Regen fire off so fast, your characters can't die unless they've been hit with an attack that takes out more than their max HP.
* ''FinalFantasyMysticQuest'': Clearing a battlefield with enough experience to gain a level will automatically increase your level ''again''. Also, [[spoiler:four words: Cure Kills Dark King]].
** To be fair, the levelling system means that for the next level along you need to get the experience required for the 'skipped' level along with it as well. Also, [[spoiler: for people that were wondering why the spoiler qualifies, this is a case of cure working on something it's not supposed to work on (and indeed, only one of the party members' cure works this way).]]
* The [=PS1=] version of ''FinalFantasyTactics'' had an awesome glitch that could let you get all the abilities of certain jobs. If you had enough JP to buy a skill, you could press down square, hit accept, then exit, which could make your JP for that job 9999 (though it didn't work for every job). This lead to fun things like Half-MP Bahamut in Dorter slums.
** There was also an item duplication glitch. Putting a weapon in a character's left hand, and a shield in the right, and hitting optimize at the item shop would swap out the weapon, by putting the one you had back in your bag, and purchasing another from the shop. This could then be used to get infinite copies of one-time only weapons.
** There was also the Samurai's reaction ''Blade Grasp'' that allowed characters to block not only swords, but arrows or even bullets. It works in the PSP version as well, and it's awesome. Catching bullets!
*** If the character using Blade Grasp has 100 brave, no blockable attack used on him will work. Set up every character in your party like this, and [[GameBreaker enemies incapable of magic attacks won't even bother to fight. They'll just stand around.]] Not exactly a bug (the AI is programmed not to do anything with a 0% chance of success) but it definitely looks like one.
** If you use a gun to jump on something with Blade Grasp equipped, you'll [[http://www.youtube.com/watch?v=Y-Tzqac9dL0 skywalk.]]
** The first stage of the Deep Dungeon/Midlight's Deep occasionally spawns a male Time Mage... who [[SweetPollyOliver isn't actually male]]. The Mage in question is female in every sense except her portrait and in-battle sprite. She can be [[HeelFaceTurn Invited]] into the team (and remains a crossdresser should you try), even using Bard sprites for the female-only Dancer class. It could, in theory, be a very obscure ''VideoGame/FinalFantasyV'' reference, but more likely it's just a very funny and ultimately harmless bug.
* Blitzball in ''VideoGame/FinalFantasyX'' has the AI of the computer-controlled players completely forget the player's existence if he swims to and stays by his team's goal. It's easy to win by scoring a goal, getting the ball the next turn, and swimming over to the goal, then waiting for the time to run out.
** For some silly reason, the Cover ability works on the various worm monsters when they use Regurgitate to spit out a character they swallowed earlier. The result is the user teleporting into the worm's mouth and being spat out in place of the intended character, which causes the "protected" character to become invisible (Save for their weapon), but still usable, which serves no purpose other then looking ridiculous.
** Although not really a bug, but equally silly looking, casting a summon causes dead characters on the field to ''get up and run away.'' When the summon finishes or dies, the characters run back onto the field and promptly pass out.
* Thanks to some backwards math, the Saw item in ''Final Fantasy Legend (SaGa)'' is an instant kill against strong monsters, like the final boss, instead of weak monsters.
** Plus martial arts weapons, which get stronger the fewer charges they have left, stack. List a near-empty Headbutt above a fully stocked one and the fully stocked one will do as much damage for each use!!
* ''SaGa2'' fixed those bugs, but added a few more, most of it Robot-related (new class). Robots get stat bonuses for their equipment as long as they have it equipped. Wearing martial arts weapons gives Agility, but they don't deal the progressively higher damage per use. But once a Robot uses up said weapon, it disappears and they still keep the stat bonus.
* ''SagaFrontier'' has Takonomics, named in honor of the man who discovered it: in Koorong, the price of gold goes down as you sell ingots and back up as you buy, but this calculation is (erroneously) made ''before'' any actual physical inventory changes hand. You can therefore manipulate the gold market in the shop menu such that when you actually sell your gold, you get more money back. Then you travel to Nelson, where gold ingots are always sold at a fixed price, and repeat until you have all the money you'll ever need.
** In addition, the well-loved Overdrive-Stasis trick, even though it ''seems'' like it may have been on purpose due to the moves descriptions("Temporarily gain infinite speed" and "freeze time in battle"), is actually a glitch- see Zaraktheus' last post [[http://www.gamefaqs.com/boards/198537-saga-frontier/51404644?page=36 here]] for an in-depth explanation.* It can be taken even further with the use of the Shadow Servant spell, which creates a shadow doppelganger that copies any spell or attack you use, effectively doubling the damage dealt in those eight turns.
** this glitch has a similar effect if a snake oil item is used by the caster on himself in lieu of Stasis, without the side effect of being in stasis after Overdrive ends. This means that time Lord does not have to complete the Rune Quest in the four quests which he is recruitable, and could be the most useful character in the game.
** The Junk Shop glitch, which allows you to get endless free stuff from the Junk Shop in Scrap: just attempt to sell a [=HyperionBazooka=] that you don't have and you get seven free items. Perfect for either kitting yourself out with DiscOneNuke[=s=] or building up enough money to engage in Takonomics.
* Hoo boy, ''{{Pokemon}}''. With the absolutely insane amount of people playing the numerous games around the world, many of the glitches in certain generations are widely known and abused, most of them found in ''Red and Blue'':
** In all generations, critical hits ignore ''enhancements'' to the appropriate defensive stat. In Generation I, they also ignored ''penalties''. So a critical hit from a Normal move did only 1 point of damage to a Rock type even after a few Screeches while a non-crit attack with the same move did significantly more.
** The first generation was riddled with Good Bad Bugs, including but not limited to warping everywhere from the very first town, even past the Elite Four, getting every Pokémon you want including Mew (not random), leveling a Pokémon from Level 1 to Level 100 in one battle by EXP underflow, walking through walls, etc.
*** The Japanese versions of the first generation games (except Yellow) had glitches based around the 11th item of the game, and some Pokémon. Wanted to instantly level up to 100? You could do that. Wanted an exorbitant amount of items? Same deal. In fact, you could "create" Pokémon with this glitch and a combination of things to do. For example, how to create Mew: You need three Pokémon. First slot: "Mew"; second slot: a water Pokémon; third slot: any Pokémon. Go to Route 1, get into a wild Pokémon battle, press Select on your 11th item, switch to the Water Pokémon, escape. Press Select on the 11th item again. Find a wild Pokémon, press select on your 11th item, switch to your other Pokémon. You should now have a Mew!
*** One of the most popular glitches is the Cinnabar Coast glitch (which also works on Seafoam Island), where there's no data for what Pokémon you're supposed to encounter there, so it uses the same data as the last place you were where you could fight and catch Pokémon, including ones found at the Safari Zone. However, if instead you talked to the Old Man who teaches you how to catch a Weedle, your name would determine what Pokémon (at monstrously high levels) could be found there -- including the fan-favorite glitch Pokémon [[TheMissingno MISSINGNO.]] , which allowed the player to duplicate hard-to-find items such as Rare Candies (which you can feed to a Pokémon to immediately increase its level) and the Master Ball (can be used to automatically capture any Pokémon, but you only got one during the course of a normal game).
**** The reason this works is because the game stores MISSINGNO.'s Pokédex info on the same place as the data for how many of the sixth inventory item you have, so just catching a glimpse of MISSINGNO. would give you 128 of that item, and actually catching it would give you 255, giving you practically enough Master Balls to catch the entire Pokédex and still have an extra 104 balls to spare. This glitch was fixed in the Spanish versions of ''Pokémon Red and Blue'', as it was apparently discovered before it was released in that language.
*** Another glitch allowed the user to randomly encounter any Pokémon in ''Red and Blue'' in the wild, making it catchable... including the Event-only Mew, not to mention all sorts of randomly generated glitch Pokémon, with equally random move names and types (what you encounter using the glitch isn't random, actually, it's based off your last battler's Special stat).
*** Another glitch that blurred the GameBreakingBug line was a save corruption glitch in Gen I. Normally, if the Game Boy was reset while saving, the save file got corrupted and the game rejected it, insisting the player start over (or just go back to their previous save in later generations, which make back-up saves). But if the game is saved before receiving the first Pokémon and reset at the right moment, the game saves the number of carried Pokémon as 255 instead of 0. Switch a couple of Pokémon and now the item count is 255 when the normal limit is 20 items. What's in the other 235 slots? Pretty much everything else in the game, like the player's coordinates, the current area, the rival's name, etc. Switching items can lead to some interesting gameplay effects, including an [[http://tasvideos.org/1860M.html extremely short game]]. This has since then been taken even further with other [=TASes=] that abuse the bug to [[http://www.youtube.com/watch?v=ry72jYferEo beat the game in slightly over a minute]] or [[http://www.youtube.com/watch?v=p5T81yHkHtI essentially allow the player to rewrite the code on the fly with their innate]] RapidFireTyping.
*** In [=FireRed and LeafGreen=], there is the Nugget Bridge on which you can beat five trainers and then get [[VendorTrash a Nugget]], only for the guy giving the Nugget out to turn out to be a Team Rocket recruiter who will battle you when you turn him down. However, he gives you the Nugget ''before'' you battle him, so if you lose you get sent back to the Pokémon Center and the guy keeps acting as if you never talked to him, ''including'' giving you a Nugget, so you can keep losing and getting another Nugget each time. Contrary to popular belief, this glitch does not work in the original games, as you only have one chance to fight him, even if you lose.
*** A bug in the Yellow version can make Pikachu like the player a lot from the first hour of play (use a Potion on it over and over again; even if it doesn't restore health, it still makes Pikachu like you).
*** This one is more like a musical quirk than an actual bug, but if a Pokemon happens to evolve after defeating Gary/Blue in the Indigo Plateau, the music just goes silent until Professor Oak congratulates the player instead of looping the victory theme, since the "evolution jingle" doesn't loop. [[http://www.youtube.com/watch?v=KxMstD8iWNM&feature=plcp]]
** The cloning glitch in ''Gold and Silver'': You could get multiples of one-shot Pokémon by shutting off the power of one Game Boy during a trade with proper timing (because the link cables used in the first two games couldn't send and receive data at the same time); and whatever item they held was duplicated as well, if you needed more Master Balls to get the Legendary Beasts.
*** Another way to clone Pokémon in G/S is as such: go to your computer, pick the mons you want, put them on your team, and save your game, then put them in storage. Then save your game again. As soon as the saving message gets to the word "off" in "Please don't turn off the power" (ironic, no?), shut off your Game Boy. You will now have one of each Pokémon on your team, and one of each in the storage box, and they will have the same held items as well.
**** This glitch can be used to farm the starters, normally only available as part of a gone-forever three-way choice at the start of the game. Save just before you pick, choose a starter, go catch a common Pokémon, deposit the starter in your box, then do the almost-save glitch; you'll boot up at the starter choice with your ''previous pick'' in the box you selected (unfortunately, this does not save the information for those starters in your Pokédex).
*** Early copies of the Japanese versions of ''Diamond and Pearl'' (removed from later and international versions, and not in Platinum at all) had a [[http://bulbapedia.bulbagarden.net/wiki/Surf_glitch glitch]] allowing you to Surf out of the door of the first Elite Four member and into the black void at the edge of the screen; the big quirk about this glitch is that, if performed correctly, it will lead you to the event-only Pokémon Darkrai and Shaymin. [[GameBreakingBug Performed incorrectly, however]]...
*** The [[http://bulbapedia.bulbagarden.net/wiki/Celebi_egg_trick Celebi egg trick]] is absolutely brilliant in every way. It's almost a pity that things like this are so rare if not nonexistent these days.
*** And then there's a new cloning glitch introduced in ''Pokémon Emerald'' that did the same thing, except with linked Battle Tower matches.
*** There's also two cloning variations in Generation IV; item (easy to perform, JP-exclusive) and actual Pokémon (hard to perform, requires Wi-Fi, not restricted otherwise). Seriously, I wouldn't be surprised if every generation has an item cloning glitch...
** And this picture wouldn't be complete without the Toxic Leech Seed glitch: use both of said attacks on your opponent, and as Toxic's effect of doubling damage from poison effects increases, so will Leech Seed's damage, in other words, twice as much damage each turn AND restoring a ''lot'' of your own HP.
** In another Pokémon related example - the Acid Rain glitch that blurs the line between GameBreakingBug and this trope - in short, if Pursuit [=KOs=] a withdrawn 'mon while any weather effect is in play, the game goes insane - all weather effects are turned on and Pokémon get harmed by their own abilities that aren't meant to do damage ("Pikachu was hurt by Static!", etc.) - in short, HilarityEnsues; but if Castform or Cherrim are sent out, the game will make them keep switching between their various forms until the game is turned off.
** [[http://www.youtube.com/user/kuriatsu This person]] exploited the Pokémon bugs to hell and back.
** In the fourth generation, there is a glitch called [[http://bulbapedia.bulbagarden.net/wiki/Tweaking Tweaking]]. The relies on the player cornering so fast that the game fails load the appropriate graphics of a new area, allowing the player to walk through a black void to any location in the game. It has potential to allow access to Event Legendaries.
** Due to how the GTS works in the fourth generation games, one can use a program on their computers to "spoof" it and produce any Pokémon they want to receive, with any attacks, items, nature, etc. Guess GameFreak forgot to put a failsafe in...
** And recently, someone made a new program that supports Black and White by taking advantage of the exact same oversight! Will GF ever learn?
** In ''Pokémon Emerald'', the part of its random number generator that creates wild Pokémon's stats never reseeds. Therefore, with great timing (hit the right 60th of a second), you can get a Pokémon with great stats (perfect stats can take hours, so it would be frustrating if you hit the wrong frame). It also works in the DS games, however you will have to set the DS's date and time, too, and to make it a little harder, many actions in ''[=HeartGold=]'' and ''[=SoulSilver=]'' can advance or skip a frame or two.
** Another glitch with the GTS allows you to evolve trade-evolution Pokémon without actually trading them. Basically, put the Pokémon up for trade, but request an impossible Pokémon in return (like a Lv. 9 or under Mewtwo). While it's sitting there, engage in a trade in the GTS using another one of your Pokémon. Once that trade is done, retrieve the Pokémon you put up for trade, and it will evolve! You can combine this with DiskOneNuke to get the likes of Kingdra and Machamp as early as the THIRD Gym.
** A bug in Pokémon Stadium 2 allows you to get infinite continues in any cup (but not Gym Leader Castle). Just have a suspended game, then start any cup (not from the suspended game), and make sure that you have at least one continue. After that, whenever you lose, choose "Suspend" then choose "Continue without Suspending". Et Voilà! No continues are lost. This is very useful because [[TheComputerIsACheatingBastard the game is heavily rigged towards the CPU]], especially in Round 2. This bug doesn't work in the original Stadium because if you try this, the game would just take you back to the screen with the Continue/Suspend/Quit options. But the original Stadium is easier anyway if you use loads of Psychic-types.
** There's a glitch in ''VideoGame/PokemonColosseum'' that allows you to use any Pokeball an infinite amount of times.
* ''WildArms'' has an item inventory glitch where if you switched places of items during battle after having other characters use them, it reduced the number of the wrong item. How this works is that an empty inventory space is still marked as "containing" the item that once occupied it (at the beginning of the game all the empty spaces are marked as duplicators or something), so if you used an item marked as "0", it'd roll "back" to 255. If you decided to duplicate [[RareCandy Apples]], then your characters could become little walking gods almost literally a couple of hours into the game.
** You can do the same thing in ''WildArmsXF'' by having 1 item, then having a Harpy steal it in battle and then using it at the same time.
** The same glitch is accomplished in the SNES version of ''VideoGame/FinalFantasyV'' by combining the Steal and Throw commands with the 2-Handed ability and some inventory management. Furthermore, because the shops aren't programmed to handle quantities higher than 99, you can sell your newly stolen items one at a time and never run out, yielding infinite cash as well.
** A similar bug occurred in ''Pokémon Colosseum'', being the first game in the series where you could catch Pokémon in Double Battles. One could use their first Pokémon's turn to throw a Master Ball, and on the second turn, switch the positions of the Master Ball and another ball. The Master Ball would catch the Pokémon but stay in your inventory, so you could catch every single Pokémon in the game from that point on with the Master Ball. Naturally, this was fixed in ''Pokémon XD''.
** ''Baldur's Gate 2'' has another example of integer underflow. By using a potion from inventory and then switching it with another item, the other item gets used instead. This can give you several billion valuable gems, essentially granting you unlimited money from the start of the game.
* Many of the spells in ''BaldursGate 2'' were broken, making mages godlike, even more so than they are supposed to be. For example:
** 'Mislead' would create an illusory image of the caster and turn the caster invisible. The invisibility would not be dispelled as long as the image lasted, so you could beat everyone to death with a stick at your leisure, with the enemies being none the wiser.
** Spells cast through 'Project Image' were not removed from your spell pool, allowing you to cast all your spells twice, or as many times as you memorised the 'Project Image'. Also, any monsters summoned through this spell weren't subject to the limitations placed on summoning, so you could conjure an army of planetars and watch them beat even the hardest encounters for you.
** 'Simulacrum' created a duplicate of the caster, also duplicating any items they held in their quickslots.
** 'Simulacrum' and 'Project Image' also ''stacked'', with a PI doppelgänger being able to cast Simulacrum and vice versa. Careful use of spell slots made it possible to rapidly amass a massive army of cloned mages.
*** Better still, one of the two was immune to the summoning limit of five creatures. Thus they could bring forth massive armies of insanely powerful creatures, without running over the limit.
** The special wild mage spells 'Reckless Dweomer' and 'Chaos Shield' were all broken, making this class powerful beyond wildest dreams. Spells cast through Reckless Dweomer weren't subject to one spell in a round limit that mere mortal mages had to observe. Using the robe that reduced casting time you could easily get four or five spells off in the time it takes for the enemy mages to cast one. The Chaos Shield, though not supposed to stack with itself would nevertheless do that if cast through a spell sequencer, virtually guaranteeing that you would never get a harmful wild surge.
*** One of the Wild Surges could lead to the cap of five summoned allies being completely ignored, as an Area Effect on your Mordenkainen's Sword led to you being surrounded by seven or eight razor-edged death engines. (One [[LetsPlay Let's Player]] had this happen on an elemental summoning spell and ended up reloading the game because it happened in quite a small room, meaning he had no idea what was going on.)
** The 'Talk and Fight' bug was another useful, though very situational, bug: Any non-hostile character whom you are currently talking to or have a character lined up to talk to will have their AI disabled and will not go hostile while the character ordered to talk to them is underway. This allows you order one character to engage an NPC in dialogue, while ordering the other members of your party to, well, engage the NPC in less courteous modes of communication (like, say, a sword to the shin). The NPC, still waiting to be talked to, will sit there and take it as long as the would-be talker is still en-route and for several seconds afterwardse. While it will not work on any enemy that requires a scripted event to die (such as the BigBad and the most difficult BonusBoss), it does wonders against the game's literal dragons who are not hostile towards you by default. AI mods were eventually released to kill this problem.
* In the first ''BaldursGate'', one can export and import characters, and in the tutorial area there's a simulated Party that has good items for the low level (plate mail, a + 1 shield, wand of heavens, etc). Normally, any attempt to loot and walk out is thwarted since "Those items are illusionary". Clever players figured out you can save in the party tutorial stage, export the character, and then import them into a new game, allowing them to have equipment they should not have at that point, or enough vendor junk to buy good items your character shouldn't be able to buy - making the game up until the Mines a breeze. Sadly, they made the tutorial items in ''Baldur's Gate 2'' unusable if you tried the same trick.
* ''Amulets & Armor'' has a great bug dealing with the "death cam", the red-tinted view of the world you see when you die. Your character is actually still alive, the game just disables the keyboard. However, ''A&A'' has mouse navigation too, which it doesn't disable, letting you explore (and even beat) levels while dead.
* One of the skills that can be learned well into ''[[{{Lufia}} Lufia: The Ruins of Lore]]'' is Sacrifice, a free move that deals 999 damage to a non-boss enemy but kills the user... unless you target ''yourself'', in which case Sacrifice is an awesome skill that fully heals yourself without cost.
** There are also two easy ways to get huge sums of cash quickly. The first uses Blue Tea, an item found only in Ordens (limited time offer!) that can be bought in bulk for 100 each and then immediately sold back for 150. Later, when the blacksmith in the beginning area becomes available, a simple bug can be used to get a limitless amount of whatever item he just made (except the last), creating an even quicker supply of cash. Stock up on cash when you get the chance, and you can buy the very expensive and (at that point in the game) [[GameBreaker game-breaking]] Zircon equipment later.
** Before ''Ruins of Lore'', there was ''Rise of the Sinistrals''. One of the BonusBoss enemies, the Egg Dragon, had the highest amount of HP possible. However, the programmers failed to cap his HP, and beating him is a simple matter of healing him with the weakest potion and then attacking.
*** The other BonusBoss, the Master Slime, is more of a case of PuzzleBoss disguised as a GoodBadBug: you need to either kill him through pure damage or kill your own party to win the battle properly. However, neither option is easy, since you only have 3 turns to kill him and the first thing he does is heal your party to full, and if the 3 rounds pass without him dying, he attacks himself and kills himself instantly. Either way you can't really lose the battle ''per se'', but not doing the above causes him to say that you've failed and he won't give you a key to a room with a bunch of {{Bragging Rights Reward}}s inside, forcing you to redo the entire BonusDungeon from the beginning for another attempt since it has no save points.
* In ''VideoGame/CastleOfTheWinds'', [[CastFromHitPoints Casting from hit points]] lowers your constitution stat (and thus your maximum HP), but if done with the beginning spell Magic Arrow your HP will stop just shy of zero, allowing you to safely decrease your constitution until it suddenly wraps around and becomes maxed out. Thus, when creating a character, one can set constitution as low as possible in order to raise the other stats, then use this to have all near-optimal stats.
** Watch out for enemies that can drain your stats, including constitution, in the second half of the game. If they drain constitution from you while you're exploiting this bug, you won't be able to have it restored until your current constitution wraps back around and drops below the level you originally set it to.
* Although both have been fixed, ''VideoGame/{{Diablo}} 2'' had a couple of fun ones for a while. The big one was the homing/pierce bug, which let Amazons with the Buriza-Do Kyanon unique crossbow and the Guided Arrow skill strike an enemy up to 4 times with said skill, with obvious results. The other one was the Marrowwalk glitch. Said item gives charges of Bone Prison at level 33 (when the skill level cap is 20 without items). If a Necromancer, who can learn the skill naturally, equipped the boots but had yet to put an actual point into the skill, the game used the 33 given by the boots for synergy purposes. That means over a 150% increase in synergy power compared to actually leveling the skill, which meant a lot considering how all the bone skills tend to synergize with each other.
** The first ''VideoGame/{{Diablo}}'' had a cloning glitch: if you picked up an item off the ground at the exact same time as left-clicking a potion from
* In ''VideoGame/ChronoCross'', Lord Viper goes into a secret room in the bar at Termina at one point to receive his level 3 tech, [=FlagBearer=], and an accessory, the Dragoon's Glory. However, if you step into the hall right outside the secret room without going into the main bar area, you can go right back in. Then, if you examine the place where the flag used to be, you will get another [=FlagBearer=] and Dragoon's Glory. The tech is useless to get multiples of, but the accessory is probably he best in the game. You can do this to acquire enough Dragoon's Glories to outfit the entire party.
* ''VideoGame/KingdomHearts2'' has a [[http://www.youtube.com/watch?v=gkuHiNCSDvE bug involving Trinity Limit]] in the original Japanese version that causes it to always inflict the maximum number of combo hits. This makes fighting bosses a joke when you're dealing over 4 bars of their HP with a single attack in under 10 seconds.
* ''VideoGame/BookOfMagesTheDarkTimes'' has a glitch where a single trip to the Mana Cave can grant you more skill points than you're possibly able to spend. In the early game, trips to the Mana Cave are the only way to level up at all; the upshot of this is that you can be almost as strong as the game's BonusBoss before your ''first battle'', completely removing any difficulty whatsoever for the entire rest of the game and allowing you to [[CurbStompBattle curb-stomp]] even the early HopelessBossFight.