For other glitches in this generation, seeList of glitches in Generation II

This is alist ofPokémon battle glitches inGeneration II games.

Pokémon Gold, Silver, and Crystal

Beat Up desynchronization

This can happen whenBeat Up is used in a link battle. Normally, Beat Up does not allow Pokémon with a non-volatilestatus condition to participate in the attack, but an error in the game's code prevents it from working as intended on the side that used Beat Up.

If the Pokémon with a non-volatile status condition has such an amount of remainingHP that this valuemodulo 256 corresponds to the index of the Pokémon that used Beat Up (between 0 and 5), the side that used Beat Up will have the Pokémon with a status condition also participate in the attack, causing desynchronization and potentially other glitches as the battle goes on. The opposing side handles the move correctly.

Belly Drum effect

When a Pokémon usesBelly Drum, itsHP is deducted by 50% and itsAttack stat raised by up to 12 stages, ensuring that even theAttack stat of a Pokémon with anAttack stage of -6 can be maximized. This is accomplished through executing the command used bySwords Dance by a maximum of 6 times; however, the command is erroneously called once before verifying that HP of the user can be deducted by 50%. This means that if the user doesn't have enough HP to use the move, the Attack stat will be incorrectly boosted by 2 stages. The game will state that the attack has failed.

Catch rate

Thestatus conditions of paralysis, burn, and poison increase the catch rate by 0 as opposed to by 5.

Fast Ball oversight

TheFast Ball is supposed to quadruple the catch rate against all wild Pokémon that canflee (a mechanic unique to Generation II), but only does this for three of them:Magnemite,Grimer, andTangela.^[1] additionally, the Fast Ball has no boosted success rate on Raikou, Entei, and Suicune (when roaming), which it was likely intended to do.

Love Ball oversight

TheLove Ball only gains acatch rate of 8× onPokémon of the samegender and species as the player's Pokémon, rather than on Pokémon of the opposite gender.

Moon Ball oversight

TheMoon Ball is technically able to gain a 4× catch rate modifier, but the exact circumstances are impossible in normal gameplay.

In the game data, each Pokémon Evolution is stored as three bytes: themethod of Evolution, an additional parameter, and the evolved species. For instance,Clefairy evolves byMoon Stone intoClefable, which is stored as 0x020824: namely, 02 is the method ofEvolution by item, 08 is theindex number of theMoon Stone, and 24 (hexadecimal version of theNational Pokédex number #036) is theindex number ofClefable. In the case of a Pokémon withbranched Evolutions, those Evolutions are placed next to each other. After all the Evolutions of a given Pokémon, there is a terminator byte with the value 0x00. If a Pokémon does not evolve, there is simply no Evolution data for it but the byte with the value 0x00 is still present as usual (this being the first byte for a Pokémon with no Evolutions, it is located where the method of Evolution would be).

At first, the Moon Ball checks if the wild Pokémon is able toevolve by any item, and then it is supposed to determine if the item used is specifically the Moon Stone. However, it checks for theBurn Heal item instead because it has theindex number 0x0A, which in the previous generation was the sameindex number used by the Moon Stone.

Instead of checking for the Evolution item next to the method of Evolution, the Moon Ball incorrectly attempts to check for the Burn Heal item three bytes after the method of Evolution. This is the next byte after the evolved Pokémon, which contains the method of the next branched Evolution or the 0x00 terminator byte. The index number 0x0A would refer to the 10th Evolution method. However, there are only five programmed methods of Evolution.

Therefore, the Moon Ball applies a 4× catch rate modifier for a Pokémon with at least two branched Evolutions: the first branch must be an Evolution by item, and the second branch must be an Evolution by a specific method that does not exist in-game.

If the wild Pokémon istransformed into another species, the Moon Ball still checks only how the original species evolves, not the transformed species (although the catch rate modifier is still impossible to obtain nonetheless).

Dragon Fang effect

TheDragon Scale boosts the power ofDragon-type moves rather than theDragon Fang.

InPokémon Stadium 2, the Dragon Fang boosts Dragon-type moves as intended. Curiously, the Dragon Scale retains itsheld item status and continues increasing Dragon type moves by 10% in that game.

Dude glitches

If theDude is prompted to show the tutorial of catching Pokémon when the player has a full box, the game will glitch. Effects vary based on the language/version of the game, with the effects in Gold/Silver being more minor (in the English version it is possible to briefly see a HUD with a Level 0 male?????, but not freeze the game), except in Korean Gold/Silver which may cause a post-battle sprite misalignment glitch without a freeze. Since the dude won't show the tutorial after the player has caught a Pokémon, but the event will activate when the player walks on a specific tile on Route 29, the way to perform this glitch is the following:

1. Start a new game and advance until Silver battles the player for the first time.
2. Heal in theCherrygrove'sPokémon Center.
3. Poison the player's first partner Pokémon. The way to poison it varies depending of the game: either the player can encounter aSpinarak during the night^GS or aWeedle during the morning^SC inRoute 30, and let it poison the first partner.
4. Deliver the Egg toElm.
5. Walk either inside the lab or inNew Bark Town until the first partner Pokémon faints and the player is teleported to Cherrygrove City, effectively skipping the catching tutorial.
6. Fill up the box in the PC.
7. Return toRoute 29 and walk as if going to New Bark Town.
8. In the edge, theDude will be prompted to show the player the catching tutorial; accept the tutorial.
9. The game will glitch when the Dude selects a Poké Ball.

The dude money glitch only occurs in the German version ofPokémon Crystal.

Exp. Share formula

APokémon with the sameoriginal Trainer as the player that is sent intobattle with anExp. Shareheld will gain 50% of theexperience twice, which, due to rounding, may not equal 100%.

Experience amount

APokémon that gains an amount of experience consisting of five digits will not have the number displayed correctly. This is possible with anoutsider Pokémon holding aLucky Egg used at theTrainer House. The lowest opponentlevel required for achieving such feat is 82 for Pokémon with an experience yield of 255 (Chansey orBlissey), and the lowest experience yield with which this is feasible is 208.

Experience underflow

Main article:Experience#Experience underflow glitch

Level 1Pokémon using the "medium-slow" growth algorithm will jump from level 1 to level 100 after gaining a low amount of experience points (less than 54 if the total experience is 0).

HP bar animation

A Pokémon with 49HP or more will deplete the HP bar at a slower rate than intended when taking damage. Due to an issue with the order of the code within the game, a value that would help to set a delay that was partially dependent on the maximum HP of the Pokémon, sets instead a constant delay that does not change with different HP values. This results in extra delays in the animation updating and prolongs the animation of the bar dropping.

A Pokémon with 48 HP or less is not affected as each HP is equal to one or more pixels of the HP bar, thus skipping any delay.

Leveling past 100

If a Pokémon above level 100 levels up due toexperience in battle, its level will be reset to 100. If a Pokémon levels "down" to 100 in battle, it will attempt to learn all of its level-up moves between levels 1 and 100 (other than moves it already knows).

Unlike in the previous generation, aRare Candy does not work on a Pokémon above level 100.

Lock-On/Mind Reader oversight

WhenLock-On orMind Reader are in effect, the movesAttract,Curse,Foresight,Mean Look,Mimic,Nightmare,Spider Web andTransform cannot hit targets in the semi-invulnerable turn ofFly orDig, and moves cannot lower stats of targets in the semi-invulnerable turn of Fly or Dig (status moves such asString Shot will fail, andadditional effects of moves such asBubble will not activate).

Menu scrolling oversight

A flag (bit 0 of memory address FFAC) in memory determines whether options can be scrolled through by holding a direction on the d-pad rather than simply pressing it, which is used by menus such as the bag. This flag is normally unset after closing the menu, and is not usually set in battle menus, meaning the player must tap through battle move menus instead of holding a direction.

Watching the staff credits after defeatingRed keeps the bit set, allowing the battle options to be scrolled through. This effect is cleared however after resetting the game and reloading the save, which is probably a reason why the glitch does not work with credits triggered by entering theHall of Fame (which resets the game afterwards).

Opponent Full Heal and Full Restore oversight

If an opposing Trainer uses aFull Heal to cure their Pokémon, it will not be cured ofNightmare (even after waking up fromsleep) or ofconfusion.

If an opposing Trainer uses aFull Restore to cure their Pokémon, it will not be cured of Nightmare (even after waking up from sleep). However, it will be cured of confusion.

The Full Heal and Full Restore properly cure a Pokémon of both Nightmare and confusion if used by the player.

Park Ball graphics corruption

If thePark Ball is used from the Ball pocket of theplayer'sBag on awild Pokémon, the game will not reload the graphics on the battle screen, causing a temporary glitch in which part of both the Bag andbattle screens mix up until the Pokémon catching animation is over, at which point the game will show the battle screen being reloaded.

This glitch happens because the Park Ball is not intended to be used from the Bag, so it isn't programmed to switch into the battle screen when it is used in this way.

Present damage

Main article:Present (move)#Generation II

InPokémon Gold and Silver, themovePresent has a damage formula of its own. This causes thelevel,Attack, andDefense variables of the regular damage formula to be replaced. Thus, the move deals unusually large or small amounts of damage, depending on thePokémon. Additionally, Present calculates type-effectiveness twice, which causes Present to only inflict a quarter of the normal damage against Rock-type and Steel-type Pokémon.

InPokémon Crystal, both bugs were fixed for regular battles by having Present use the standard damage formula. The old formula from Gold and Silver is still used during link battles to preserve backwards compatibility. This was fixed entirely inPokémon Stadium 2.

Pursuit-Revival glitch

Using a Revive, Max Revive or Rare Candy on a Pokémon that fainted fromPursuit after a switch will revive the Pokémon with the non-volatile status it had before fainting. This applies both to healing inside and outside of battle.

Rival's lowered individual values

See also:List of NPC's Pokémon's DVs in Generation II

The rivalSilver has a team with loweredindividual values (also known as DVs or IVs) in later battles due to an oversight. Specifically, Silver is stored in the game data as two separate characters, each with his own battle sprite:

• Silver uses Pokémon with 13 DVs for Attack, Defense, Special, and Speed during his battles inCherrygrove City,Azalea Town,Burned Tower,Goldenrod Underground, andVictory Road.
• Silver uses Pokémon with 9 DVs for Attack, and 8 DVs for Defense, Special, and Speed during his battles inMt. Moon andIndigo Plateau.

For comparison, allNPC's Pokémon from Generation I also had exactly 9/8/8/8 DVs. In Generation II, each NPC Trainer has their own set of DVs shared by their Pokémon, but several of those Trainers (including multiple Trainer classes) still have 9/8/8/8 DVs like before.

Sandstorm Spikes glitch

	This glitch is in need of research. Reason:Is there a party position/permutation of switches or anything that causes this not to work? Do Poké Dolls work? Does party count matter? What happens exactly when the fainted team's health is later restored? Why is it "rematching trainers in the grass" may not work? You candiscuss this on the talk page.

This glitch occurs with a Pokémon in aSandstorm which faints, when there are activeSpikes against the player's Pokémon. Sending out three more Pokémon in succession which will immediately faint from the Spikes, can result in the last Pokémon surviving but with 0 HP. The player can then proceed to escape the battle (i.e. with a successful catch), and every Pokémon will remain in the party with 0 HP.White outs may not occur.

This glitch leads to other derivative sub-glitches, such as the previously known 'instant victory' effect (also used by "any%"speedrunners in the past witharbitrary code execution orbad cloning); in which entering any battle causes it to end (of the partial sort; the battle ends before the Pokémon is sent out rather than the start of the battle itself), effectively allowing the player to always win.

SRAM clear errors

An internal function in the code for wiping the save file known unofficially as "ClearWRAM" does not function correctly.^[2] It may be worth noting, there are more specific glitches in the game, such as "Hall of Fame SRAM glitch" (box 2+ data becomes invalid, and allows the player to ultimately obtainglitch Pokémon and????? without bad cloning, if the player clears the save file and enters the Hall of Fame without saving in between). This glitch is loosely similar to Generation I SRAM glitches related to impartial clearing, such as the "ghost Bicycle" phenomenon, "save abuse" and string names leftover from the previous save file with- (move). Another SRAM glitch is the Japanese Poké Communications Center SRAM glitch (mentioned atthe header Pokémon Communication Center, though that one is related to exhausted or broken save batteries).

Stat rollover glitch

If a Pokémon's effective stat would exceed 1024, the Pokémon's stat is decreased by 1024 (for a minimum stat of 1) duringdamage calculation only. While most methods to increase stats cap at 999, theThick Club,Light Ball, andMetal Powder do not.

While it is possible for this to occur for all of these items, this most readily occurs with Marowak (sincePikachu andDitto require stat boosts to be received viaBaton Pass for this to occur). If aMarowak with anAttack stat of at least 256 usesSwords Dance while holding aThick Club, its Attack will be reduced by 1024 (minimum 1) duringdamage calculation only.

During damage calculation, if the attacker's (Special) Attack or the defender's (Special) Defense is higher than 255, both are temporarily divided by 4, then (regardless of whether the stats were quartered) both the attacker's (Special) Attack stat and the defender's (Special) Defense stat are takenmodulo 256. Thus, stats that are greater than or equal to 1024 (256×4) will be treated incorrectly.

InPokémon Crystal, this bug was fixed for regular battles but still occurs during link battles to preserve backwards compatibility. This was fixed entirely inPokémon Stadium 2.

Trainer Counter/Mirror Coat damage

InTrainerbattles only, if the player uses a healing item or aPoké Ball during the same turn as the opponent'sCounter orMirror Coat, theirdamage will be of at least 4HP, twice the minimum standard damage for neutral moves (2 HP).

Transform glitches

Main article:List of Transform glitches

Pokémon Gold and Silver

Encore-Disobedience

	This glitch is in need of research. Reason:Technical information such as the cause is wanted, spading (for example, does it only occur with transformed Pokémon?/can it disobey in every way) as well as confirmation on which versions it occurs in (as it was assumed to be Japan-only after disassembly research regarding the Japanese version). You candiscuss this on the talk page.

This glitch involves the moveEncore and anoutsider Pokémon. If the outsider Pokémon is locked in to a move under Encore, it may still disobey the player. While under Encore, agame freeze orglitch dimension can occur after the Pokémon disobeys the player.

Present text overflow

IfPresent is used by theplayer's Pokémon on a Pokémon with 8 or more characters in its name, e.g.Venusaur, and the game tries to heal the foe, but fails due to them having full HP, the “n't” will appear between the first and second lines. Result:

Trainer House

Main article:Trainer House glitches

Pokémon Crystal

Battle Tower text glitch

In v1.0 of EnglishPokémon Crystal (and not v1.1), a glitch causes enemy Trainers in theBattle Tower to always use the texts of female Trainers. This is due to the game attempting to use the sixth character of the Trainer's name to determine the gender.^[3]

Heavy Ball junk data glitch

In Crystal, theHeavy Ball's algorithm incorrectly retrieves the weights ofKadabra,Tauros, andSunflora, causing them to become junk data that is interpreted as massive weight, giving these Pokémon +40 capture modifier.^[1]

References

Related articles

This glitch Pokémon article is part ofProject GlitchDex, aBulbapedia project that aims to write comprehensive articles on glitches in the Pokémon games.

• Articles with accompanying video
• Glitches in need of research
• Glitches
• Glitches by game