Mario and friends are challenged to play baseball with Bowser. So they play ball games with each other to decide who should play Bowser. The rules are the same as any other baseball game with some exceptions. Like other baseball games, each team gets three strikes, three outs, and four balls per inning. However, you can choose to play less than nine innings. You can also choose from Exhibition, Challenge, Toy Field, and Minigame modes. Exhibition mode is one game between two teams. In Challenge mode, you choose a team to play every other team; you can get the other teams characters by completing certain challenges. When you beat the other teams, you get a chance to play Bowser's team. In Toy Field mode, up to four players take turns to get the most points; players receive points by hitting the ball at certain spots, which consist of out, 1-, 2-, or 3-hits, or homerun spots. You can get a turn by catching the ball when your opponent hits the ball. At the start of Exhibition and Challenge modes, you choose your team captain. In Exhibition mode, you also choose team members, but in Challenge mode, your team members depend on which captain you pick.
All the team captains have star pitches and star hits. The characters can also pitch fastballs and change-ups. You can unlock more characters through Challenge mode.