Known Mechanics Bugs

[Marty-D]

Bugs are now listed in the 'Mechanic Bugs' project

https://github.com/Zarel/Pokemon-Showdown/projects/3

You can comment in psim.us/dev or on this bug with any questions or to signal your intent to work on a specific bug listed on the project.

[GraillLord]

@Marty-D Sorry for the answer delay, I wanted to fix the 2 turn moves issue but it seems solved ? (Still not sure cause the bug is still on live)

Two-turn moves should ignore redirection on the charging turn fixed in 06567f8.

[Marty-D]

@acz13 I don't know offhand.

@GraillLord The two-turn move issue you're talking about and the one you just quoted are different bugs. The one you quoted was indeed fixed, as you can see by its absence from the checklist.

[GraillLord]

@Marty-D Hi, I've been working a lot recently and had little time for solving bugs, but concerning http://replay.pokemonshowdown.com/anythinggoes-285817545 I solved it just by replacing if (lacksTarget) { with if (lacksTarget && move.flags['charge']) { in data/scripts.js at line 261

edit: Two-turn moves should not fail with no target fixed in #3523.

[Marty-D]

Confusion damage should not be affected by opposing Unaware fixed in https://github.com/Zarel/Pokemon-Showdown/pull/3530. Gen IV - Implement accurate damage formula fixed in https://github.com/Zarel/Pokemon-Showdown/pull/3583. Gen IV - Damage-reducing Berries should not activate on theoretical damage fixed in https://github.com/Zarel/Pokemon-Showdown/pull/3626. Gen III - Implement accurate damage formula fixed in https://github.com/Zarel/Pokemon-Showdown/pull/3655.

[urkerab]

Source (some of these may have already been filed or fixed).

• [x] An Instructed move is never a Z-move. 6921390955a4adde6223493f16f4b40a245a7f37
• [ ] Terrain seeds should not activate before the user's terrain ability activates.
• [x] Perish Song can't hit semi-invulnerable Pokémon #3963
• [x] Decision tooltip should show user's current Ability (even after Transform/Imposter). #3969
• [x] Grassy Terrain and Leftovers recovery happen simultaneously. #3970
• [ ] When switching in one last Pokémon after a double-faint, you never get to choose the slot.
• [x] Team Preview shouldn't show shininess. Zarel/Pokemon-Showdown-Client#996
• [x] Fainted Pokémon should be replaced in their original speed order. 7785375d1410b713bb4106d7944b59a9f1ff5ac8
• [x] Levitate activates before Protect. 0646743a6dd3b515ecffa1eddb39b6bdd60abd97
• [x] Lightning Rod boosts SpA of Ground-type Pokémon. 0646743a6dd3b515ecffa1eddb39b6bdd60abd97
• [x] Ground-type Pokémon can bounce Thunder Wave. 0646743a6dd3b515ecffa1eddb39b6bdd60abd97
• [ ] Pokémon can have full IVs and change their Hidden Power type without learning Hidden Power.
• [x] Berries activate between weather damage and Leftovers/Toxic 25d0079b4febc5711108f784d97d3b9bcd67ca64

[DaWoblefet]

Adding on to the list:

• [x] Self-hit confusion will not activate Sitrus or super Sitrus (Figy, Iapapa, Wiki, Aguav, Mago) Berries (source; I also have Gen 7 Battle Video if needed) (fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4045)
• [x] Multiple Dancers will activate in order of slowest -> fastest speed, even considering Trick Room (source) (fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4009)
• [x] Thiefing a Weakness Policy triggers and consumes the Weakness Policy (source).

[urkerab]

Thiefing a Weakness Policy triggers and consumes the Weakness Policy

I think this was fixed by PR #3867.

[Marty-D]

I think this was fixed by PR #3867.

https://github.com/Zarel/Pokemon-Showdown/commit/1f6e1e8d457f5cc37612be78b711e22470fea45b @urkerab

[DaWoblefet]

A Choice-locked Pokemon using a Pledge move in a Pledge combo attack should be locked into the Pledge move the following turn (source).

Marty edit: Fixed in https://github.com/Zarel/Pokemon-Showdown/commit/c28347edda25991145efbd43695f74fc0a61c9b9.

[killemall420]

I have left a post regarding to the Hidden Power issue here: https://github.com/Zarel/Pokemon-Showdown/issues/4026

[Zarel]

Clarification: This issue is meant for mechanics bugs that have been confirmed by a staff member - generally either Marty, DaWoblefet, or some other collaborator who has witnessed a battle video and the corresponding PS mechanic and can confirm that they differ.

[DaWoblefet]

Some Encore-related bugs (source):

• [x] Encore should fail on Assist, Copycat, Me First, Nature Power, and Sleep Talk (all moves that call other moves cannot be Encored). (fixed in https://github.com/Zarel/Pokemon-Showdown/commit/cb91464a4933c14f919a7ff671f00aecd6c8bed4)
• [ ] The target of a failed Encore should be ambiguous to both players; that is, the animation shouldn't play out. This happens with other moves that bring up the message "But it failed!", like Fake Out, Disable, etc., so it can probably be generalized in this way. Sucker Punch is already implemented in this way.

Marty edit: removed "Encore should fail on a Z-move. Right now, Encoring a Z-status move locks the target into the base attack of that Z-move." since I added it to the first post a few days ago.

[QuiteQuiet]

Sucker Punch is already implemented in this way.

Sucker Punch still leaks the information about the target in the console, so this isn't entirely resolved for Sucker Punch either.

[DaWoblefet]

• [x] Misty Terrain should not display "The < Pokemon > surrounds itself with a protective mist!" if the attack is not directly inflicting a preventable status. E.g. Thunder Wave should display the message, but not Nuzzle. Right now, this extra message results in an information leak to the player (source). (Marty edit: moves with secondaries were already handled; fixed the rest in https://github.com/Zarel/Pokemon-Showdown/commit/df05e12f591389cab297cd222761a41fa571c871)

[Slayer95]

not Nuzzle

But should Nuzzle advance the RNG?

[Marty-D]

A Pokemon Transformed into a Mega Evolution should not be able to use Z-Moves fixed in https://github.com/Zarel/Pokemon-Showdown/commit/934fc5b40d7b2c8764df5c2edeaad6428f3c1da5. After additional research, Transforming into a Primal Reversion displayed the same behaviour.

[Marty-D]

Gen II - Accuracy checks should be capped at 255 before BrightPowder fixed in https://github.com/Zarel/Pokemon-Showdown/pull/3926.

[Marty-D]

Encore should fail against Z-Powered Status moves fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4298.

[DaWoblefet]

There was a bug reports post about a couple of interactions with Ally Switch that have been known for a while now but seems to have been overlooked. These replays show it hasn't been fixed yet.

• [x] When a player self-targets a Pokemon using Ally Switch, the attack should fail (display "But it failed!"), not be redirected into an opponent. Fixed in https://github.com/Zarel/Pokemon-Showdown/commit/733ea72d4f3a9db3139ce9330156e4df4b481528
• [ ] Whena player Ally Switches after self-Leech Seeding a target, the effect of Leech Seed should be redirected to the new ally Pokemon. The bug reports post shows a video of what that looks like.

[DaWoblefet]

Important bug with Assurance in Doubles; it is doubling in base power in situations where a target was KOed and the Assurance was redirected into the opponent from the original Assurance target. I'm assuming that Assurance is checking the slot it targeted to see if it had taken damage yet, not the slot it actually is attacking. See bug reports post.

[Marty-D]

Gen IV - Baton Pass, Healing Wish, Lunar Dance, and U-turn fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4519.

[DaWoblefet]

The interaction of contact Z-moves and Protect behave incorrectly. The behavior was originally described here, but appears to have been overlooked as it was currently mentioned again to me. As a summary:

• Contact Z-move into King's Shield: after the damage is dealt, the Z-move user receives -2 Attack. To be clear, this does not factor into the damage for that Z-move.
• Contact Z-move into Spiky Shield: after the damage is dealt, the Z-move user takes 1/8 damage from Spiky Shield.
• Contact Z-move into Baneful Bunker: after the damage is dealt, the Z-move user is poisoned.

You can see the behavior in the linked post's video, but I also tested and have Battle Videos myself if needed.

Marty edit: To clarify, the above is only true of Z-Powered moves. For hackmons purposes, the moves themselves used without Z-Power are completely unaffected by protection moves; they don't even reduce damage dealt. Fixed in https://github.com/Zarel/Pokemon-Showdown/commit/538ac5ca5559fbf788becf2472562f29f5022f09

[Marty-D]

Gen IV - Accuracy should be checked before Ability immunities fixed in https://github.com/Zarel/Pokemon-Showdown/commit/bbeb041e701ed0f9ea6d3375a798d9166e9faac1.

[mid-kid]

Sorry to come knocking where I maybe shouldn't, but since King's Rock still needs proper implementation in gen2, and I've recently discovered some King's Rock-related bugs, I might as well make sure they're known of.

Both of these bugs are related to the messy working of Beat Up.

First of all, even when no mon has been able to hit due to having a status effect or being fainted, the king's rock may activate: This doesn't happen when the move is protected against, or fails for whatever other reason.

And the other bug happens when only one 'mon is present in the user's party, and prevents the King's Rock effect from being triggered, overriding the behaviour above. This can only be seen in-game through the fact the substitute won't be raised either, as both "effects" are skipped: (Not raising the substitute is only a graphical bug, the game will still treat it as if it's present, and raise it again if a different move is used)

I've documented both bugs in pokecrystal (but it's yet to be merged at the time of writing), here and here, if you're interested in how it looks in the code.

[DaWoblefet]

A round of small bugs:

• [x] Transform should be copying the Focus Energy / increased crit rate status of the target when Transforming (starting in Gen 6). See this for more details. Fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4546
• [x] Pursuit should not double in power nor attack before switching if used on an ally in Doubles. See this for more details. Fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4548
• [x] Stomping Tantrum is erroneously receiving doubled base power on moves like Splash and Celebrate. See this replay for an example, this pastebin for a list of Stomping Tantrum tests I've completed myself that indicates if Stomping Tantrum is doubled in various situations. Fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4627

More serious bug:

• [x] Auras in Doubles are apparently not working for both slots, for whatever reason. The Aura boost is only calculated for one of the opponent's Pokemon, not both. See this for more details. I have not tested if this is bugged in greater capacities than what I have seen. Fixed in https://github.com/Zarel/Pokemon-Showdown/commit/ce38fe5c03a557ea6c058832438fe62736e97503

[Marty-D]

Gen II - Belly Drum mechanics fixed in https://github.com/Zarel/Pokemon-Showdown/commit/70ff3103ba24c3802c9d63a3cb6966cba5aaa7b2.

Gen II - Tri Attack should be able to thaw the target fixed in https://github.com/Zarel/Pokemon-Showdown/commit/6c8b738e7dce81657bbc792496f6a52143444cf0.

[DaWoblefet]

Went through the bug reports thread and found some more mechanics to be fixed. You can see all of these tested here :

• [x] Weather Ball should not receive doubled BP in Delta Stream. See the Twitch VOD starting at 5:20. Woble edit: tested it in ORAS as well, it did not receive doubled BP there, same as USUM.
• [ ] The final turn of Grass + Fire Pledge should deal damage, then fade its effect away. It should be like the behavior of Grassy Terrain's final turn, rather than Sandstorm's final turn. Source.
• [x] If Spite reduces the PP of a move that has less than 4 PP, the game displays the actual number of PP decremented, not a hardcoded 4. Source. Fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4590
• [x] Sky Dropping a Pokemon that never had the opportunity to attack will enable Fake Out / First Impression / Mat Block usage on a turn other than its "first" turn. Marty said this is similar to shifting behavior in Triples. See this section of my video on Sky Drop. Of note: I expected this effect to cause double Protects when used in order of Protect -> be Sky Dropped using non-Protect -> use increased priority in air as Sky Drop drops -> Protect again. However, I tried it 5 times in my testing and never got a double Protect. Fixed a long time ago in https://github.com/Zarel/Pokemon-Showdown/commit/381816574293d3626ecc16d71026c13db215128d Woble edit: not entirely at least, see this recent replay as an example. Actually fixed in https://github.com/Zarel/Pokemon-Showdown/commit/fbf21e68e92d174768cb7e5c1ac6467fe982324e!!!
• [ ] It is possible to have an active Wish for each slot in a Double Battle. Source.
• [ ] If Fusion Flare -> Fusion Bolt are used in the same turn by the same Pokemon (e.g. a Smeargle using Instructed Fusion Flare -> Fusion Bolt), the regular Fusion 2x BP multiplier should be applied. Source.
• [ ] Unburden currently retains its boost if its Ability is removed, such as with Skill Swap. In-game, an Unburden Pokemon that has lost an item will immediately lose its Speed from something like Skill Swap removing the ability from the Pokemon. Source. Marty edit: this is a client issue; the server is correctly removing the volatile.

[DaWoblefet]

More small bugs! This round of tests can be found here.

• [x] Mummy erroneously is causing Parental Bond to use the first hit's BP for the second hit as well. See this for an explanation of what PS is doing wrong. In testing, Mummy modifying Skill Link mid-strikes did not prevent the multi-strike move from knowing to still strike 5 times. Fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4890
• [x] Mid-battle forme changes (e.g. Aegislash, Mimikyu) should update weight in the same way typing / modification to an actual stat is updated. That is, if you Soak an Aegislash and it changes formes, it returns to Steel / Ghost type; in the same way, if an Aegislash uses Autotomize and changes formes, its weight is reset to base Aegislash weight. Fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4893
• [x] The exclusive Z-moves (e.g. Kommo-o's, Mew's) should be affected by Sheer Force in a similar way to being affected by Simple; that is, their Z-move is boosted and the post-Z-move effects are negated. Source. I do not know how this affects the hackmons behavior of directly using, say, Sheer Force Clangorous Soulblaze, but I imagine it should behave the same. Fixed in https://github.com/Zarel/Pokemon-Showdown/commit/9109f110bc05f44856960e8646282c572f7a460a

[DaWoblefet]

• [x] On the turn a Pokemon undergoes Mega Evolution, if Truant is given to that Pokemon before it takes an action, it should be loafing around on that turn. See these two research thread posts for the correct behavior, and this replay for an example of incorrect behavior. Fixed in https://github.com/Zarel/Pokemon-Showdown/commit/2ab375f3cc870303487aacde0d77d4c800c6b9d1.

[asingh04]

The "details" link for "Implement King's Rock properly" doesn't work anymore. Was it having any important info related to #3343 ?

[Marty-D]

@asingh04 I've edited in the archive version of the page. It's basically what is detailed in that issue but as a complete list of moves.

[DaWoblefet]

Another round of reporting bugs!

• [x] Stomping Tantrum is sometimes doubling in BP when its previous move landed into a Protect. This should never happen, and is a serious bug in doubles right now. Source.

The following 4 bugs are from my bug reports post here.

• [x] Shadow Tag messages in doubles occasionally result in an information leak to the player; moreover, if Shadow Tag is confirmed to trap a Pokemon on the left, that information reveal should be present for the trapping message on the right. See the post for a more in-depth explanation.

  If a game ends with Clangorous Soulblaze as the last move used, the boosts should not be applied. This is generalizable, see my next reply.

• [x] When Psycho Shift fails to pass a status to a target as a result of Misty Terrain, etc. it should display the appropriate Terrain message rather than "but it failed!" Fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4697

• [ ] Encore should work successfully on Shell Trap, in a similar way to the Focus Punch behavior. EDIT: see here for clarification.

[Slayer95]

Fixed the Shadow Tag leak in c3e752c87f9c8e17b079c645302002fe97f01dd6. As for the information reveal enhancement, it's not quite trivial so long as we still support Triples. However, it can probably be special-cased for Doubles in the client when the error message is received?

[Marty-D]

Stomping Tantrum is sometimes doubling in BP when its previous move landed into a Protect.

This is because of the Truant fix, but it's really just exposing the real bug here. It means that currently a turn of Dancer/Instruct forcing a successful move, then your actual move decision goes into a Protect, next turn Stomping Tantrum will be doubled. That sounds like wrong behaviour. @MacChaeger?

[pyuk-bot]

I know why that is. It’s that moveThisTurnResult saves its current value right before useMoveInner is called, and the return value of useMoveInner is only stored if moveThisTurnResult is the same as it was before the call. That’s specifically to check if a Protect move forced the value to change manually from undefined to true, but if the value was already true either from Mega Evolution or from using another move successfully, then the value would be overwritten by the value of false returned by useMoveInner to indicate that the move didn’t execute. This is easily fixed by simply re-initializing moveThisTurnResult to be undefined instead of saving the current value, or more properly fixed by actually getting useMoveInner to return something other than false when the move hit at least one Protect-like (and to make moves that call other moves from their onHit event handlers via useMove to return the value that that function returns, as such moves also rely on that comparison to the old value and are thus also currently affected by this bug, but in the opposite way). Anyone may feel free to do one of these fixes themselves as I won’t be back to my laptop for at least two hours.

Sent from my iPhone

On May 19, 2018, at 3:51 PM, Marty-D notifications@github.com wrote:

Stomping Tantrum is sometimes doubling in BP when its previous move landed into a Protect.

This is because of the Truant fix, but it's really just exposing the real bug here. It means that currently a turn of Dancer/Instruct forcing a successful move, then your actual move decision goes into a Protect, next turn Stomping Tantrum will be doubled. That sounds like wrong behaviour. @MacChaeger?

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[DaWoblefet]

Some clarifications / more bugs!

• [x] Any effect that changes stats after the final Pokemon is KOed in battle should not activate. For example, Clangorous Soulblaze, Moxie, Power-Up Punch, Close Combat, etc. all should not show any changes if the final Pokemon was knocked out. Source. Fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4777
• [x] Illusion should display the Illusion Pokemon's actual level, not the level of the target it is disguised as. Source. Mostly fixed in https://github.com/Zarel/Pokemon-Showdown/pull/4764
• [ ] If Rollout / Ice Ball targets an ally, the target of Rollout / Ice Ball in subsequent turns during the lock should be the ally. Source.

[Marty-D]

Gen III - Berry usage timing fixed in https://github.com/Zarel/Pokemon-Showdown/commit/ac71237de177b3b97ade6750eb923b59fa0f6cb7.

[DaWoblefet]

More small bugs! The first two can be verified from this Twitch VOD (will change to YouTube later).

• [x] Laser Focus should not have a fail rate. It can be used consecutively without causing the message "But it failed!" (source) Fixed in https://github.com/Zarel/Pokemon-Showdown/commit/b4b2f1ebf065ff9ee13f63202c50dbcf8a1fbc86
• [x] Beast Boost / Moxie and Soul Heart currently leaks Speed information. Soul Heart should always trigger first, then Beast Boost / Moxie (multiple Soul Hearts triggering does reveal Speed, which PS has correct). (source) Fixed in https://github.com/Zarel/Pokemon-Showdown/commit/952ccb2d804a7a1e8b5085d59b8b7f0432a02579
• [ ] Using a move blocked by Primal weather should not reveal which slot was targeted (that is, shouldn't play the animation) (source)

[DaWoblefet]

Even more small bugs (first can be verified in this video, second-fourth from video):

• [ ] Against double Intimidate, White Herb should only be consumed after both Intimidates go off (source).
• [ ] Counter / Mirror Coat currently ignore redirection; they should be affected by redirection as normal (source)
• [ ] If a Pokemon has Normalize and uses Doom Desire, Doom Desire receives the Normalize boost. This only applies if the Doom Desire user stays in (source)
• [ ] If a Pokemon has Adaptability, is Steel-type and uses Doom Desire, Doom Desire receives the Adaptability boost. This only applies if the Doom Desire user stays in. (source)

[Cureja]

• Mid-battle forme changes (e.g. Aegislash, Mimikyu) should update weight in the same way typing / modification to an actual stat is updated. That is, if you Soak an Aegislash and it changes formes, it returns to Steel / Ghost type; in the same way, if an Aegislash uses Autotomize and changes formes, its weight is reset to base Aegislash weight.

Should we remove the Autotomize volatile tag then when they change formes? That should remove the weight modification done.

[bgsamm]

King's Rock should be able to flinch after breaking a sub in Gen 2 - see #4916 (comment)

[bgsamm]

Also, I believe the double battle faint mechanics issue in Gen III has been fixed (line 2975 in battle.js).

[HoeenCoder]

https://www.smogon.com/forums/threads/bug-reports-v3-0-read-op-before-posting.3634749/page-19#post-7950168

Confusion resulted in a critical hit when the pokemon hit itself (gen 4). Confirmed as a bug by @Marty-D, don't have time to do this myself rn so feel free to pick it up.

Edit: Fixed

[DaWoblefet]

These all are from this bug reports post.

• [ ] Stomping Tantrum's base power should double if a spread move lands into a Protect + the other target of the spread move reaches a condition that would double Stomping Tantrum. It currently does not do this.
• [ ] Timing out at Team Preview in VGC matches with a team partially chosen should respect the Pokemon already chosen and select the remaining Pokemon based on party order; currently, a timeout at Team Preview just autoselects the first 4 Pokemon.
• [ ] Redirection currently doesn't work if the player targeted an empty partner slot.
• [ ] The activation of Red Card and Eject Button are Speed-based, and they lie in the same Speed bracket. Multiple Emergency Exit activations should be similarly Speed-based. Speed ties are broken LightningRod-style.
• [ ] If Magic Room negates the effects of a Terrain seed, the Terrain seed should not reactivate upon Magic Room being undone, even if the necessary Terrain is currently active or reactivates. Using Trick would cause the Terrain seed to activate again, assuming the appropriate Terrain is active.
• [ ] Future Sight should reveal the targeted slot.
• [ ] If multiple Eject Buttons would activate from a single move, only one should activate, and one that activates is determined by Speed. (LightningRod-style Speed tie).

EDIT: Adding another very minor bug:

• [ ] When a Pokemon with Beast Boost or Moxie (not Soul-Heart) uses a spread move to take multiple KOes, the Beast Boost / Moxie should apply all subsequent boosts at once rather than one at a time. E.g. a Moxie Krookodile taking 3 KOes should receive its Attack boost all at once to get +3, rather than +1 +1 +1.

[kjsuarez]

Is anybody currently working on 'Berry interaction with Unnerve switching to Unnerve'?

[SadisticMystic]

Speaking of berries...

• [x] If a Pokemon receives a Leppa Berry (such as through Trick) while one of its moves is already at 0 PP, it should be able to use the berry immediately, even if the 0 PP move is not its most recently used move. Replay--note the berry correctly fires on turns 22 and 32 (when Eruption is the most recently used move), but not on turn 44. If two or more moves are already at 0 PP when it receives the berry, it should restore the one that's earlier in its movelist.
• [x] If you Fling a Leppa Berry (thereby forcing it to be eaten), it should restore PP to the first move in the target's movelist that has any PP missing. Showdown's current implementation is to restore whichever move has the lowest current PP count, even if it leads to the nonsensical situation of "restoring" a move that's already full. Replay Fixed in eecde00

[mid-kid]

Good job closing an active issue, github.

[Zarel]

I wonder if we just make a new issue just to clear out historical cruft from this one.

[MathyFurret]

in the meantime nobody say "this fixes #2367" or github will close it D:

[LegoFigure11]

Research needed

• Hacked genders in past gens (see #2327)

Continuing discussion from #2327 - it is possible to hack the genders of Pokemon in gens 4 - 7 independently of the PID (Editable value is stored at 0x40 in Gen 4 and 5 pkm structure, and 0x1d in Gen 6 and 7 - this value is initially calculated from the PID but can be changed, enabling the forcing of particular gender (or lack thereof) to a Pokemon, even if that Gender is unavailable on it).

Editing the gender independently of the PID is NOT possible in Gen 3 however, which essentially means that Pokemon cannot have Illegal genders (e.g. no Genderless or Male Blissey in Gen 3).