If one had multiple shiny charms in Pokémon White 2, would their effect stack?

Question

And do they have to be in the Key Items case to work?

Answer 1

No.

I think there is a similar question on this site, but It's for a different game and I can't find it... so okay.

This stacks with most other modifiers which increase
the Shiny encounter rate, such as the Masuda method.

Notice that it says other modifiers, so no. Plus, as far as I know, there is no way other than cheating to get multiple Charms.

Source + Experience

Comments

Bulbapedia's page on it likely say that because it doesn't stack with itself in normal gameplay because it requires hacking to obtain a second one. I don't think that "it stacks with other modifiers" is saying that it stacks with everything but itself.

---

Sorry for the late reply (I'd forgotten about this question for a while), but I agree with Hellfire. I know the only way to make this happen is by cheating, but I'd still appreciate a definitive answer not based on speculation or an incorrect interpretation of Bulbapedia's description of the Shiny Charm.

Answer 2

Shiny charms do not stack as an item, but you can add multiple to your inventory through modifying the save. It doesn't seem to do anything though, but I did only add 4 (the game being White 2) , and haven't noticed an increase. I can experiment more though, but I'm not the best with math and calculations.

Comments

assuming that, if they do stack, they stack additively and not multiplicatively, four shiny charms would put you at 9/8192 in BW2. That's significantly higher than usual, but I don't think that would be enough to notice an increase. I think the best way to tell would be to hack in at least 4,000, and if you get a shiny about half the time, it stacks, and if it's significantly more than half the time, it stacks multiplicatively.