History Main / GoodBadBugs

* ''VideoGame/GHOSTSquad'' will still award the "EXCELLENT!" point bonus for Lacard Zimone, the Mission 2 boss, if you fire before his third shot ''even if you miss''.

* In the UsefulNotes/TRS80 game ''VideoGame/{{Starfighter}}'', pressing a number key 0-7 accelerates you to a pre-selected speed of 2^(number) - 1. Thus, pressing 3 accelerates you to speed 7, pressing 4 accelerates you to speed 15, etc.. It didn't take the players long to discover that if you pressed two number keys at the same time, you'd accelerate to an intermediate velocity -- and that holding down all the number keys 0 through 7 at the same time would accelerate you to speed 254, faster than any spacecraft you'd ever encounter.

* {{UsefulNotes/Steam}} sometimes messes up the prices of games during sales, resulting in the ''VideoGame/NarutoUltimateNinjaStorm'' games being on sale for $5.61...with its original price being erroneously listed as ''[[https://pbs.twimg.com/media/COjtVf7UwAAVilE.png 184 quadrillion dollars]]''. Though being part of a LongRunner AnimeAndManga franchise, [[CrackIsCheaper it probably feels like it costs that much]].

* On the ''UsefulNotes/{{Commodore 64}}'', Raster Interrupts broke a ''number'' of established rules of the system. Normally you could only have one color in the border at one time, one text color, one background color, two colors per cell (or four on Multicolor Bitmap Mode), only 8 sprites, and sprites overlapping in the border, but by abusing Raster Interrupts you could utilize multiple colors at once, draw many more colors per cell, and have sprites in the double-digits that went anywhere on the screen. Basically, since the device "draws" the screen one line at a time, you can use machine code to interrupt this process mid-way and then send new instructions, which allows you to do all sorts of trickery. This was, and still is, abused ''mercilessly'' by the game developer and demo scene.

** The fact that the NTSC color signal causes artifacting as a whole. Computer programmers were initially frustrated that it made text borderline unreadable at 80 columns with some color combinations due to the burst overlap causing blurring to the text, which doesn't happen on RGB monitors. However, they soon discovered that by carefully placing their pixels and choosing their colors, they could create colors that were never in the computer's palette to begin with. And the kicker is, this bug is a fault with the way NTSC signal works, meaning it was exploited by every single computer system with a color limitation but output to TV- documentations show that the trick has been used on the UsefulNotes/AppleII, UsefulNotes/Atari8BitComputers, UsefulNotes/{{Commodore 64}} and even [[UsefulNotes/IBMPersonalComputer PCs]]. Unfortunately, this didn't work for people in PAL regions as PAL was widely advertised to be immune of artifacting (although in truth, it was simply immune to the NTSC method- it has it's own color-mangling problem as outlined below). These techniques faded away as video chips gained more colors and computer makers switched to cleaner RGB connections.
** The UsefulNotes/ZXSpectrum had a similar possible effect, due to the way PAL encoding works. One popular demo (published on a tape magazine) squeezed over 300 colours from the Speccy's 8-colour palette.

** The ability to run at 1.5 times Leon's normal speed by switching to the [[ShotgunsAreJustBetter Striker]], raising it and then quickly equipping another weapon before the laser sight could activate ([[http://speeddemosarchive.com/ResidentEvil4.html useful but cautiously used]] in {{speedrun}}ning).

* ''VideoGame/WizardsAndWarriors'' specifically in ''Ironsword'' there is a glitch that allows the player to take the weapon of the previous level to the next one. This allows the player to bypass the level 2 and 3 puzzles and even beat the level 2 boss where you normally need the Blightwater with the Windbane instead. This has become a important trick for when speedrunning the game.

* ''WesternAnimation/WreckItRalph'': Vannelope can use her tendency to glitch out to pass through obstacles on the track, including other racers. [[spoiler:When she becomes a playable character in the end, some players work out how to do this when playing her, and because it's DifficultButAwesome she quickly becomes a favorite.]]

* The video game adaptation of ''Film/SpiderMan2'' allows you to fly into the stratosphere if you're hit by the train.

* The original revision of the famous Commodore SID sound chip had an imperfection in its implementation where audio from the three waveform generators are mixed incorrectly, as well as a flaw in the filter implementation. As it turns out, these flaws combine to give the SID chip the ability to produce PCM sound clearly with its PSG. When a revised version of the SID chip that fixed all these flaws was later released, it was found that PCM audio reproduction became muffled.

* The original revision of the famous Commodore SID sound chip had an imperfection in its implementation where audio from the three waveform generators are mixed incorrectly, as well as a flaw in the filter implementation. As it turns out, these flaws combine to give the SID chip the ability to produce PCM sound clearly with its PSG. When a revised version of the SID chip that fixed all these flaws was later released, it was found that PCM reproduction became muffled.

* In ''[[VideoGame/DragonBallZTheLegacyOfGoku Dragon Ball Z: Buu's Fury]]'', you have to get a Senzu Bean (an item that gives full health and Ki) early in the game to give to Gohan for a FetchQuest, but you also can eat it before you deliver it. Does the game want you to get another bean if you eat the delivery? No, Gohan will accept the one you don't have, [[OverflowError causing]] [[UsefulNotes/PowersOfTwoMinusOne 255]] [[OverflowError of them to appear in your inventory]]. For reference, you're normally {{cap}}ped at carrying three Senzu Beans.

* In ''[[VideoGame/DragonBallZTheLegacyOfGoku Dragon Ball Z: Buu's Fury]]'', you have to get a Senzu Bean (an item that gives full health and Ki) early in the game to give to Gohan for a FetchQuest, but you also can eat it before you deliver it. Does the game want you to get another bean if you eat the delivery? No, Gohan will accept the one you don't have, [[UsefulNotes/PowersOfTwoMinusOne causing 255 of them to appear in your inventory]]. For reference, you're normally {{cap}}ped at carrying three Senzu Beans.

** In ''Ten Desires'', due to the way [[BonusBoss Mamizou]]'s creature bullets are animated, the boolean that tells the game that a bullet has already been grazed doesn't activate. What this means is that by simply sticking close to any creature bullet, the player can accumulate ridiculous amounts of graze, far more than the actual number of grazed bullets. While all of Mamizou's cards feature this to some extent, it's most noticeable during [[https://www.youtube.com/watch?v=0rncEnJerb4 Wild Deserted Island]], which fills the whole screen with nothing but creature bullets.