The gameplay of Mario Party: Island Tour resembles that of the rest of the Mario Party series. The main focus is still on various boards, where players roll dice to try and get to the end, while playing minigames along the way.
The majority of the gameplay takes place on one of the various game boards. 2-4 players compete against each other to try to reach the end of the board first. Player order is determined by an initial dice roll. Then, for each turn, players roll their die and move the number of spaces shown on the die.
Different events are caused by the spaces a player lands on, and they vary between boards. All boards feature minigames, which the players will frequently encounter. These minigames take the players somewhere else, where they compete against each other to complete certain challenges. If there are ties, the results of the minigames are determined by a dice roll. Winners will receive different prizes depending on the board, such as bonus dice or mini-stars.
There are five game modes in Mario Party: Island Tour. The primary multiplayer mode is Party Mode, where the majority of the gameplay takes place. Other modes include Minigames, which feature the minigames separate from the board games, Streetpass Minigames, the online mode, Bowser's Tower, a single-player mode, and Collectibles, the store mode.
- Party - Primary mode of the game, where 1 to 4 players can play against each other or CPU opponents to the end of seven game boards.
- Minigames - Can play the minigames that have been unlocked in Party Mode and/or Bowser's Tower, without needing to play anything outside of them.
- Streetpass Minigames - The online mode of the game, where non-local players can play through the various minigames.
- Bowser's Tower - Single-player mode of the game, where players must climb 30 floors, completing minigames. Every fifth floor will have players encountering a boss battle.
- Collectables - The in-game store, where players spend their Party Points (earned from Party Mode) to unlock songs, sound clips and figures.
The space each character lands on determines what happens for them that turn. Therefore, they have a large impact on how the game plays out.
- Dash Space: Move forward 2, 3 or 5 spaces.
- Item Space: Get a random item. Items vary for each board.
- Green Space: Ends the turn.
- Piranha Plant Space: Knocks the player backwards.
- Event Space: Activates a special event determined by the board.
- Duel Space: Starts a minigame.
- Bowser Space: Activates a random, often negative, event.
- Dead End Space: Stops the player, regardless of their roll.
- Warp Space: Moves a player to another's spot on the board.
Banzai Bill's Mad Mountain only:
- Banzai Bill Space: Launches Banzai Bill
- Switch Space: Changes where Banzai Bill launches from.
- Safe Space: Keeps the player safe from Banzai Bill.
- Danger Space: Puts the player in danger of being hit by Banzai Bill.
Shy Guy's Shuffle City and Kamek's Carpet Ride only:
- Card Space: Gives the player a random card.