"Paper Mario" is set in the Mushroom Kingdom as the protagonist Mario tries to rescue Princess Peach from Bowser, who has imprisoned the seven "Star Spirits", lifted her castle into the sky and has defeated Mario after stealing the Star Rod from Star Haven and making himself . To save the Mushroom Kingdom, rescue Peach, get the castle back, and defeat Bowser, Mario must locate the Star Spirits, who can negate the effects of the stolen Star Rod, by defeating Bowser's minions guarding the star spirits. The player controls Mario and a number of partners to solve puzzles in the game's overworld and defeat enemies in a turn-based battle system. The battles are unique in that the player can influence the effectiveness of attacks by performing required controller inputs known as "action commands".