Approved Add an "Acid Rain" Rule for Gen 4

[berry]

https://bulbapedia.bulbagarden.net/wiki/Acid_rain

Acid Rain is a glitch present in the Pt/HG/SS Gen 4 Cartridge games. Although it is not included in Gen 4 Competitive, I believe it would be useful to add as a modifier that can be added to a match (something like inversemod or stabmonsmovelegality) to let users more closely replicate the cartridge's mechanics if they choose to do so. This is also important for formats such as Gen 4 Pure Hackmons, which aim to replicate cartridge mechanics as closely as possible.
Similar glitches such as the Gen 4 Fire Fang Glitch are already implemented on PS.

 

[SadisticMystic]

The problem with implementing Acid Rain is that if Castform shows up in it, the canonical behavior is for the game to lock up as it endlessly tries to switch back and forth between forms. Showdown has a policy of not attempting to stay accurate to official mechanics when those mechanics lead to crashes, desyncs, or other loops that make it impossible to proceed with the battle.

 

[Zarel]

I don't think we actually have that policy?

Anyway, I'd be 100% in favor of Acid Rain as an optional rule, with the lockup being implemented as a forcetie. Smogon will probably not apply it to their formats, but there's no reason why others shouldn't.