Since Pokémon apparently get 2x STAB from being one type, if you're using, example, an Eevee with Adaptability, would Adaptability stack with the one-type STAB and create a 4x multiplier?
I'm sorry. That's not how Adaptability works. If a mon has Adaptability as its ability, it CHANGES the STAB from 1.5x into 2x. Also, this can work even if the mon in question is dual-typed.
Adaptability is a Pokémon Ability that adds 50% more damage to a Pokémon's move if the Type of that attack is the same Type as the Pokémon using it. An example is Eevee, a Normal-type Pokémon, using Tackle, which is also a Normal-type move.
