The user generates another move depending on the battle's current terrain. It generates Stun Spore in grass and tall grass (as well as in puddles and very shallow water), Razor Leaf in very tall grass, Surf while surfing on top of river and ocean water, Bubblebeam while surfing on top of pond water, Hydro Pump while diving underwater, Rock Slide on any rocky outdoor terrain, Shadow Ball inside of caves, Earthquake on beach and desert sand, and Swift everywhere else (including link battles).
Almost always goes last; in trainer battles, the target is switched out for a random member of its team. Escapes from wild battles. Has no effect if the target has Suction Cups or used Ingrain.