List of glitches (Generation I): Difference between revisions

{{Incomplete|article|Loads of missing newly discovered glitches; could also use some better organization; probably should make a section for "all handheld games" vs "all games" seeing how there's lots of in-battle glitches that were alternately fixed or still occur in Stadium}}

This is a '''list of glitches''' that occur in the [[Generation I]] [[core series]] [[Pokémon games]].

{{GlitchResearch|Glitch Pokémon which evolve by items}}

Pokémon can be evolved without the use of an [[evolutionary stone]], provided that the player has sent out a Pokémon with the equivalent identifier of the relevant evolutionary stone item and finishes the battle with that Pokémon in the same battle that a Pokémon that evolves using an evolutionary stone levels up.  

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Celadon Hotel is based off a design of a [[Pokémon Center]]. In this map, if the player stands in front of where the PC would be in a Pokémon Center, the player can access an invisible PC.

All known invisible PCs do not exist in {{game|Yellow}}.

Extra invisible PCs:

[[File:RB Lift Key Glitch.png|thumb|right|256px|The Lift Key glitch]]

This glitch was fixed in {{game|Yellow}} due to the Grunt automatically dropping the Lift Key as soon as he is defeated.

This [[glitch]] occurs in all localizations of {{game|Red and Blue|s}} and in the European localizations of {{game|Yellow}}. In the Italian Pokémon Red and Blue, there's also a word in this dialogue that overlaps the right border of the text box. In English Pokémon Yellow, it was fixed but the dialogue contains a typo instead.

{{main|Pewter Gym skip glitch}}

If the player has some [[Fainting|fainted]] Pokémon and some that can fight, they can deposit all but the fainted Pokémon. After three steps the player will black out. However, if two steps are taken, then the game is saved and reset, it resets the step count. This means the player can enter a battle with no Pokémon. In {{game|Yellow}} only one step is needed for the game to black out so this glitch does not work.

==Yellow==

This glitch was fixed in [[Generation II]].

===Pikachu off-screen glitches===

With more advanced applications of the glitch, it is possible to max out Pikachu's happiness or cause it to do one of four special actions (winking, the fishing action, the confused action or the 'disapproval' action) when the player character talks to it.

==In all games==

If a {{p|Ditto}} transforms into another Pokémon and then switches around the copied moves with the '''SELECT''' button, after the battle the Ditto will not have {{m|Transform}} and will instead have {{m|--}}.

===0 ERROR glitch===

Prior to [[Generation II]], having the player character draw in a [[Pokémon battle]] causes the victory theme to play even though the player has lost.

===Bide errors===

The stored damage from {{m|Bide}} can hit (but not always) a Pokémon under the invulnerable stage of {{m|Fly}} or {{m|Dig}}. If Bide deals damage to a Pokémon under Fly or Dig, the game will reveal its sprite early. This also causes a small animation glitch with Dig where it appears that the enemy Pokémon rises from the ground off the top of the screen instead of the enemy rising up from 'underground'. There is no animation glitch with {{m|Fly}} because the game has no animation on the opponent's side of Fly returning from the top of the screen to the ground—the game only reveals the sprite.

===Burn and paralysis stat penalties stacking===

* If the Pokemon whose turn it is not right now is burned, its current Attack stat gets halved.

===Cable Club escape===

===Changing NPC sprites===

===Counter glitches===

In Link Battles, Counter may also trigger desynchronization errors. This occurs due to the last move pointed by the cursor in the move selection menu being treated by the last move actually used if the Pokemon switches out. This oversight can also be exploited outside of link battles to make the opponent's Counter hit or miss at will under specific circumstances.

===Critical hit ratio error===

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

===Defrost move forcing===

PP is deducted from the move the Pokémon uses in other player's game (even in its owner's game), regardless of its current PP. If the move had 0 PP, it underflows to 63 PP and removes the effect of one [[PP Up]].

===Ditto assumption===

In Generation {{gen|I}} and {{gen|II}}, any Pokémon that uses {{m|Transform}} is regarded as a {{p|Ditto}} in its new form; this means that if the player catches a {{p|Mew}} or a [[glitch Pokémon]] which has used the move Transform, or a Pokémon which has used Transform via {{m|Mirror Move}}, instead they will obtain a Ditto. Mew turning into Ditto was not an issue, because wild Mew could not have been legitimately encountered. This system was later changed in Generation III, where wild Mew could be encountered.

===Division by 0===

The attacker's current Attack/Special stat is higher than 255 and the defender's current Defense/Special stat is lower than 4.  

The defender's current Defense/Special stat is 512 or 513 and the defender has used {{m|Reflect}}/{{m|Light Screen}}. In addition, if its current Defense/Special stat is 514 or higher when {{m|Reflect}}/{{m|Light Screen}} is up, it will be treated as if it was much lower due to a roll-over glitch.

===Dual-type damage misinformation===

This glitch does not occur in {{eng|Pokémon Stadium}}.

If an attack is super effective or not very effective against one type and does no damage against another type (for example, {{m|Dig}} against {{p|Charizard}}), the game will erroneously state that the attack missed.

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{{typetable|Poison}}

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{{typetable|Grass}}

In Generations I and II, level 1 Pokémon using the "medium-slow" growth algorithm will jump from level 1 to level 100 after gaining a {{tt|low amount|less than 54 if total experience is 0}} of experience points.

===Gate access restriction===

Certain [[gate]]s<!--which ones?--> which can be accessed after the player passes [[Cycling Road]] will have guards that restrict the player from passing if the [[Bicycle]] is deposited in the PC, even though the player does not require a Bicycle.

===Ghost identity unveiling===

When encountering a {{OBP|Ghost|literal|ghost}} in [[Pokémon Tower]] without having a [[Silph Scope]], it is possible to see its true identity by viewing the stats of any Pokémon in the player's party. However, this glitch is only graphical, and it is still impossible to [[Pokémon battle|fight]] or catch it.

===Ghost Marowak bypassing===

Using a [[Poké Doll]] on the {{OBP|Marowak|ghost|ghost Marowak}} in [[Pokémon Tower]] with or without the [[Silph Scope]] will cause it to permanently disappear.

===Glitch City===

It is similar to the [[Sky Drop glitch]] in [[Generation V]], because both glitches permanently make the opponent unable to move until fainting or switching (although switching out the Pokémon is normally not possible).

===HP recovery move failure===

If a Pokémon uses a recovery move ({{m|Softboiled}}, {{m|Rest}} or {{m|Recover}}) and the difference between its current HP and maximum HP is 255 or 511 (or any number that leaves a remainder of 255 when divided by 256), the move will fail the same way it would when the difference is 0. This glitch does not occur in Pokémon Stadium.

===Hyper Beam + Sleep move glitch===

Furthermore, if the Pokémon was badly poisoned (by {{m|Toxic}}), [[#Toxic counter glitches|the Toxic counter will not be reset]].

===Index #000 post-capture===

If the player attempts to leave too many times when choosing their first Pokemon then the player, Prof. Oak and the middle Poké Ball's sprites will vanish. Pressing start will pull up some glitched text on the screen, but exiting the start menu will fix everything.

===Invulnerability glitch===

This glitch was fixed in {{g|Stadium}}.

If the player lures (by blocking their movement in certain directions) an NPC below a ledge that can be jumped over, it is possible to land on top of the NPC.

===Level-up learnset skipping===

For example, if a level 4 {{p|Pidgey}} earned enough experience points for defeating a single Pokémon to reach level 6, it will not learn {{m|Sand-Attack}}, a move it would normally learn at level 5.

===Leveling past 100===

In Generation I and II, if a Pokémon is obtained at a level above 100, it can be leveled up with [[Rare Candies]] up to level 255. If a Rare Candy is fed to a level 255 Pokémon, its level will be reset to 0 due to an overflow in a single byte. If a Pokémon above level 100 levels up due to [[experience]], its level will be reset to 100.

===Menu glitch===

If the player holds A when the game is saving, the menu won't disappear until player stops holding A.

===Mew glitch===

===Mirror Move glitch===

===Pallet Town NPC misplacement===

If the player stands outside of Professor Oak's Lab in Pallet Town, the person outside it will eventually stand on the Lab's door. This is because the door tile was programmed as a non-solid tile.

===Perpetual spinning animation===

If the player saves the game having just entered the Safari Zone and leaves, the game assumes that the player is just entering the Safari Zone entrance, as it does not save that the player is currently in a paid Safari Zone session. Thus, upon passing by the desk, the player is prompted to pay for another Safari Zone session, although they are now traveling out towards the town below. Because the player is supposedly in a Safari Zone session, the game counts down steps passively. Upon exiting towards the bottom into Fuschia City, the player must Fly to Viridian City and enter Giovanni's Gym. Inside, the player must walk along the spinners, proceeding to be spun around. After taking enough steps to deplete the (invisible) counter, the player freezes, the PA "ding-dong" noise will sound, and a message will pop up saying that the player's Safari Zone session is now over. If the player is in the middle of a spin while this happens, the player will be transported to the Safari Zone entrance as if they had just left the Safari Zone, and upon moving will perform the spin animation, and move slower. The player has full control over the movement of the character, the only difference is that instead of the walking animation, the spinning animation is played.

===Pokémon merging===

===Pokémon Storage System healthy party deposit===

===Psywave desynchronization===

When a Pokémon uses Psywave, a random number is generated between 0 and 255. If the player uses Psywave, if the generated number is greater than or equal to 1.5× the Pokémon's level (rounded down) or it is 0, the number is discarded and a new number generated; if the opponent uses Psywave, if the generated number is greater than or equal to the Pokémon's level, the number is discarded and a new number generated. As such, if the generated number is 0, the Psywave user's game will generate a new number, whereas the non-Psywave user's game will not. This causes all subsequent pseudo-random numbers to be desynchronized.

===Psywave infinite loop===

If a level 171 Pokémon uses Psywave, the upper bound would be 256; however, since this value is stored in a single byte, it overflows to 0, causing the same issue as a level 0 Pokémon.

===Rematching Trainers===

As the [[List of locations by index number (Generation I)|index number of Pallet Town]] is 0, the player can access 255 locations by tossing the 36th item (as tossing one ×0 item causes an underflow to 255). The index number of the [[Hall of Fame]] room is 118, so the player must toss exactly 138 of item 36 to change the warp destination to the Hall of Fame. If the player stands on the right side of the exit mat item 36 should be a [[Master Ball]], while if the player stands on the left side of the exit mat, it should be the hex:00 glitch item which would appear as some glitchy blocks with a multiplication sign in it.

====In Japanese versions====

The glitch works in Japanese Blue but the game has to be reset some time after the "!" mark appears in "(PLAYERNAME)はレポートに しっかり かきのこした!". In Japanese Yellow it is possible with the same procedure as English Red/Blue and Yellow, but in order to corrupt the number of items the player has to replace the ninth Pokémon instead of the tenth to avoid a freeze after closing the items pack.

===Save reset oversight===

Another version of this glitch can (but not always) appear when performing the Fossil conversion glitch in the Japanese {{3v2|Red|Green|Blue}}. <ref>[http://forums.glitchcity.info/index.php/topic,6621.msg190080.html Glitch City Laboratories forums - "An addendum to the Fossil conversion glitch" thread, post by Torchickens]</ref> Unlike the "New Game" version, entering and leaving Cycling Road doesn't fix the glitch.

===Silent Indigo Plateau===

In the battle against {{ga|Blue}} at [[Indigo Plateau]], if the player [[Evolution|evolves]] a Pokémon in battle and defeats Blue, the music will be muted until [[Professor Oak]] comes to congratulate the player.

===Sprite corruption===

In other generations, it may occur when a [[Cheating|cheating device]] is used.

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===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 [[Saving|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.

When loading a save file, the player usually starts facing south. This is because of the limited data in the game. This glitch causes the player to face in a different direction, which confuses the game.

===Struggle bypassing===

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.

===Substitute sprite vanishing===

Using a sacrificial move like Explosion on a substitute and having the damage break the substitute prevents the user from fainting. The sprite of the user vanishes regardless.

===Substitute + Confusion glitch===

If a Pokemon with a Substitute up hurts itself due to confusion, or due to {{m|Jump Kick}}'s or {{m|High Jump Kick}}'s side effect, damage will be dealt to the opponent's Substitute instead. If the opponent doesn't have a Substitute up no damage will be dealt to any Pokemon.

===S.S. Anne reboarding===

[[File:Pokemon Red Reboard SS Anne.png|thumb|right|The player surfing on top of the sailor]]

After the [[S.S. Anne]] leaves the dock for the first time, it's possible to make it reappear later. To perform this glitch, the player must stand one tile above and to the left of the sailor guarding the harbor, take a step right and hit the Start button at the same time, save and reboot. After verifying that the player is facing right and without moving, a Pokémon must be selected to {{m|Surf}}, thus making the player surf on top of the sailor. Then, after walking down to the harbor, the boat can be entered.

===Toxic counter glitches===

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.  

====With Rest====

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.

===Trade cloning===

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.

===Victory Road Bicycle music quirk===

This glitch occurs neither in the Japanese nor the international versions of Pokémon Yellow; instead, the Bicycle music does not play at all in Victory Road.

===Walking through an NPC===

If the player lures an NPC onto the path that Professor Oak takes to bring the player to the laboratory, Professor Oak and the player will walk right over and through her.

===Walking through walls===

===ZZAZZ===

===Shiny Ditto DV manipulation===

The Shiny Ditto glitch requires a game from [[Generation I]] and [[Generation II]], but only has an effect on a Generation II game. By trading any [[Shiny Pokémon]] to a Generation I game, having a wild {{p|Ditto}} transform into that Pokémon, then catching and trading the Ditto into a Generation II game, the Ditto will be Shiny.

===Trade evolution learnset oversight===

For example, trading a level 34 {{p|Graveler}} from {{game3|Red and Blue|Pokémon Red|s}} to {{game3|Gold and Silver|Pokémon Gold|s}} will make the Graveler evolve into {{p|Golem}}. Since it is level 34, it will learn {{m|Rollout}}. If it is then traded back to Pokémon Red, it will still have the move, but the game won't recognize it properly since it is a Generation II move, so will become {{m|TM05}}.