TheAdventuresofSuperMarioBros.3focusesonMario,Luigi,ToadandPrincessToadstool,whoresideintheMushroomWorld.Mostoftheepisodesrevolvearoundthefourcharacters'effortstopreventtheattacksmadebyKingKoopaandhissevenKoopalingstotakeoverPrincessToadstool'sMushroomKingdom.