Question

Does Roto Hatch and Flame Body stack when hatching eggs?

Answer 1

Yep.

Outside of battle
From Pokémon Emerald onward, if a Pokémon with Flame Body is in the party (even if fainted), the number of cycles it takes for all Pokémon Eggs in the party to hatch are halved. This effect does not stack with itself, Magma Armor, or Steam Engine; however, it can be stacked with Hatching Power Pass Power, O-Power, or Roto Hatch.

Hope I helped!

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Comments

I've read that paragraph at least three times in the past week and didn't know that