List of glitches (Generation I): Difference between revisions

| {{evostone|Moon Stone}}

| {{evostone|Fire Stone}}

| {{evostone|Thunderstone}}

| {{evostone|Water Stone}}

| {{evostone|Leaf Stone}}

In [[Cerulean Gym]], the [[water tile]]s have [[wild Pokémon]] data programmed in, which allows players to [[Fishing|fish]] {{OBP|Pokémon|species}}. This oversight was corrected in {{game|Yellow}}. The bug then returned in {{game|Gold and Silver|s}} but it was fixed once more in {{game|Crystal}}.

There are also invisible PCs in the same position (accessible by facing up with the coordinates x=13, y=4 xblock=1, yblock=0) in [[Kanto Safari Zone|Safari Zone]] rest houses 2, 3 and 4 ([[List of locations by index number (Generation I)|maps 223-225]]), but these positions are not normally accessible, so memory hacking must be done. [[Arbitrary code execution]] exploits [http://glitchcity.info/wiki/index.php/Invisible_PCs written using the 8F item] can allow these extra PCs to be accessible without cheating.

===Japanese Red, Green, and Blue===

'''NOTE:''' The following [[glitch]]es affect all [[Game Boy]] versions of {{game|Red and Green|s}} (1.0 and 1.1) unless noted otherwise.

A glitch believed to have been fixed in Japanese Blue and later versions, where picking up one of six specific hidden items (such as the Nugget in Rocket Hideout B3F) causes the other five hidden items to disappear. The six hidden items can additionally be revived if the player hands over a [[Fossil]] to the scientist in [[Cinnabar Island]]'s [[Pokémon Lab]].

Pokémon Red, Green, Blue <!--and Yellow?--> have two coordinate pairs for hidden items in the ROM, in the "[https://github.com/pret/pokered/blob/cbc85b4d220b31c28266a227ff8789818631c4e9/data/hidden_objects.asm hidden object]" (holds coordinates, text ID, object routine) and "[https://github.com/pret/pokered/blob/master/engine/overworld/hidden_items.asm hidden item]" (holds maps and item coordinates) databases.

[http://s1271.photobucket.com/user/Torchickens/library/Red%20and%20Green%20broken%20hidden%20items?sort=3&page=1 Six hidden items] do not have matching coordinates (and one entry for a Rare Candy in [[Pokémon Mansion (Kanto)|Pokémon Mansion]] B1F has completely missing coordinates in the hidden items database), meaning that "item picked up" flag 255 is used. Hidden item flags start from bit 0 of $D66F, hence flag 255 is bit 7 of $D68E ($D66F+($FF/8)).

$D68E is an out-of-bounds address that is updated whenever the player passes over a Fossil (not necessarily giving it away, but giving it away will work as well) with the identifier of the Fossil (either Old Amber ($1F), Helix Fossil ($2A), Dome Fossil ($2B). None of these items have bit 7 set, meaning that passing over a Fossil will bring back all six items.

The broken hidden items cannot be detected by the [[Dowsing Machine|Itemfinder]].

{{Youtubevid|THTEoXhPFRk|channel/UCZz2ixp-5T6VeAPtAMQ5v5Q|name=ChickasaurusGL|Red|Green}}

Swift was designed to never miss, however due to a programming error in Pokémon Red, Green and Blue (as well as all known revisions of Japanese Yellow), the move is capable of missing (i.e. if the foe has raised evasion, or is under the invulnerable stage of {{m|Fly}} or {{m|Dig}} or possibly from 1/256 miss chance that affects other 100% accuracy moves) unless the foe has put up a {{m|Substitute}}.

{{m|Focus Energy}} and [[Dire Hit]]s are intended to quadruple the {{DL|Damage modification|critical hit}} rate, but due to a glitch, they will quarter the chance of scoring a critical hit. This was fixed in {{g|Stadium}}.

This is because pressing the down on the d-pad actually overrides the "walk back to the right" movement, thus ignoring the return movement.

This list is presented in the reverse order to which they are stored in the game data, which is likely the order they were added to the game. Therefore, messages higher on the list take priority over those lower on the list.

If the player has an {{DL|Experience-affecting item|Exp. All}} in their bag and uses two or more Pokémon from their party in battle, then the total amount of experience gained overall will be decreased depending on the number of Pokémon used.

When [[glitch Pokémon]] have been seen on the save file, the player's [[Hall of Fame]] is badly corrupted with entirely different Pokémon, even glitch Pokémon, and very glitched characters, names and levels. This does not affect the Pokémon themselves, rather the data seen in the Hall of Fame.

In [[Generation I]], if the player manages to capture an [['M (00)]], an invisible wild {{p|Ditto}} will still be in battle with the player where 'M (00) was before, and the battle will not end. This Ditto can then be caught.

During a Link Battle, if {{m|Mirror Move}} and a {{cat|Moves that partially trap|partial-trapping moves}} such as {{m|Wrap}} or {{m|Fire Spin}} are used together, a desync may be triggered due to one game interpreting that the attack used was Mirror Move (and failing) and the other game interpreting that the partial-trapping move was used instead.

This leads to three notably glitchy stat-related effects:

===Statue collision oversight===

The glitch is performed by standing next to a [[water tile]] that is facing up, left, or right, walk in that direction and pressing start without letting go of the D-Pad. The game then needs to be [[save]]d and reset. When loading the saved data, the player will be facing in the direction that was being held down when the start button was pressed. Using {{m|Surf}} will cause the player to surf on the tile immediately south, even if it is not a water tile.

 

 

 

The player can use [[Surf]] or a [[Fishing|Fishing rod]] when facing the right or left of a gym statue. The [[Old Rod]] continues to pull up [[Magikarp]], as it ignores location, but the [[Super Rod]] (and the [[Good Rod]] in Yellow) will bring up "Looks like there's nothing in here..." everywhere other than the [[Cerulean Gym]], which has wild [[Pokémon]] normally. This is probably because the developers didn't check on the statue's tile behavior on its interaction.

In Generation I, {{m|Struggle|struggling}} can be avoided by allowing the game to self-select a move to be used, which can happen to any move used immediately after a Pokémon is {{status|Freeze|defrosted}}, or due to a handful of moves' effects ({{m|Bind}}, {{m|Clamp}}, {{m|Fire Spin}}, {{m|Hyper Beam}}, {{m|Metronome}}, {{m|Mimic}}, and {{m|Wrap}}) because of the auto-selection involved with {{cat|moves that partially trap|partial-trapping moves}}. A move used with 0 {{PP}} in this way would {{wp|arithmetic underflow|underflow}} to the maximum possible value, 63 PP, and, due to the way the data is structured, a move that 0 [[PP Up]]s had been used on would gain full PP Up status, while those on which PP Ups had been used would lose one PP Up boost. This glitch was addressed in Generation II games and later, which prevent a move from being executed if it has 0 PP.

If the target of {{m|Leech Seed}} is also under the effect of {{m|Toxic}}, Leech Seed damage will increase every turn as the N value of Toxic increases because Leech Seed and Toxic both use the same damage algorithm (N * max(1, int(0.0625*MaxHP). This was fixed as of [[Generation II]]. If the current {{stat|HP}} of the recipient of Leech Seed's HP-restoring effect is greater than its maximum HP, its current HP will be set equal to its maximum HP.

If a Pokémon badly {{status|poison}}ed by {{m|Toxic}} uses {{m|Rest}}, the Toxic counter will remain, with the N value not being reset. If a Pokémon is then poisoned, {{status|burn}}ed, or affected by Leech Seed, the damage will increase each turn as with bad poison.

To perform this glitch, player's Pokémon has to be partially trapped by another Pokémon. As it's trapped, the player should use healing items until the trapping ends. If the opposing Pokémon then puts player's Pokémon to sleep on the turn trapping ends, player's Pokémon will never move. To fix the glitch, player has to cure the sleep status.

After the player has walked 499 steps and is in an appropriate position, they must jump off the ledge so that they are in midair when they run out of steps for the Safari Game (with the glitched drop shadow sprite underneath the player). They will be warped back to the Safari Zone entrance building and the background music will stop. The player is now able to walk through walls, but attempting to leave the building at this point would cause the game to crash. Talking to the man will only cause him to say "Welcome to the Safari Zone" without actually asking if the player wants to enter. If the player walks around in the building until the poisoned Pokémon faints, they will black out and be warped to the last [[Pokémon Center]] they healed at, and from there they will be able to walk through walls anywhere outdoors. The glitch wears off when entering a door (the normal entrance square to the bridge to the S.S. Anne where the NPC normally stops you counts as a door).

Saving the game and reloading it restores normal collision effects. If the player stands on Cycling Road and saves and loads the game, they can walk around on Cycling Road without a bicycle. Saving and loading the game while on a water tile causes the player to be unable to move without the use of surf. Saving and loading the game while standing on top of the guard to the S.S. Anne allows the player to enter the bridge and then the ship.