Battle Colosseum.

Prevent all damage counters from being placed on Benched Pokémon (both yours and your opponent's) by effects of attacks and Abilities from their opponent's Pokémon. (Damage is not an effect.)

You may play only 1 Stadium card during your turn. Put it next to the Active Spot, and discard it if another Stadium comes into play. A Stadium with the same name can't be played.