Mechanics [Gen 4] Flinch while U-turning into a Pokemon with King's Rock

[Cazenovia]

What type of bug are you reporting? Mechanics

What is the bug?
Last week, my friend Etchy posted a video on his Twitter showing that in Gen 4, U-Turning into a Pokemon holding a King's Rock can cause the opposing Pokemon to flinch, even if the Pokemon using U-Turn does not have any flinching item. As far as I can tell, this interaction only occurs with King's Rock/Razor Fang, and no other items or abilities can cause this particular effect. This interaction is not present at all on PS!.

Doing some tests, I found that the opposing Pokemon will not flinch if the Pokemon using U-Turn holds a King's Rock and the Pokemon switched in does not have the item or has the ability Klutz. The move can still flinch if the Pokemon using U-Turn has Klutz, as long as the Pokemon switched in does not.

Are you able to replicate it? If so, how?
Etchy's cartridge footage
My footage
Klutz footage

 

[GeniusMike]

I just stumbled upon this video on YouTube this morning. It's such an obscure bug but as the video says, it has to do with the order the game does its checks and it checks for the item too late in the sequence. It should thus be simple enough to implement on PS and it isn't game breaking (as in won't literally crash the battle or make it infinite) so it should be implemented. Hopefully the right people see this and get it implemented and document the change where applicable.

 

[Yeetgodremastered]

What type of bug are you reporting? Mechanics

What is the bug?
Last week, my friend Etchy posted a video on his Twitter showing that in Gen 4, U-Turning into a Pokemon holding a King's Rock can cause the opposing Pokemon to flinch, even if the Pokemon using U-Turn does not have any flinching item. As far as I can tell, this interaction only occurs with King's Rock/Razor Fang, and no other items or abilities can cause this particular effect. This interaction is not present at all on PS!.

Doing some tests, I found that the opposing Pokemon will not flinch if the Pokemon using U-Turn holds a King's Rock and the Pokemon switched in does not have the item or has the ability Klutz. The move can still flinch if the Pokemon using U-Turn has Klutz, as long as the Pokemon switched in does not.

Are you able to replicate it? If so, how?
Etchy's cartridge footage
My footage
Klutz footage

This is not a bug, the way the game checks things left an oversight where kings rock/razor fang is checked after the move effects happen, this oversight is present in earlier games too, but to no effect as you cannot replicate it without a damaging switch move

 

[Cazenovia]

This is not a bug, the way the game checks things left an oversight where kings rock/razor fang is checked after the move effects happen, this oversight is present in earlier games too, but to no effect as you cannot replicate it without a damaging switch move

This is a bug because PS! currently does not have this mechanic implemented.