You must play 2 different Legendary Summit cards at once. Both cards act as a single Stadium while in play. If a [C] Pokémon is Knocked Out by damage from an attack from the opponent's Pokémon, that player takes 1 fewer Prize card.
おたがいの[C]ポケモンが、相手のポケモンからワザのダメージを受けてきぜつしたとき、とられるサイドは1枚少なくなる。