Boo's Crystal Ball is an item featured in Mario Party 4. A player can use the item to summon a Boo to steal Coins or a Star from an opponent. A Boo's Crystal Ball can be purchased at item shops or won in Mini Minigames. The only reason why it replaces the Boo Bell from older Mario Party games is because it shows players their opponent getting robbed by the Boo . The player can stop the Boo from stealing a lot of coins by merely taping rapidly, but their coins still get stolen from the Boo.
 Names in Other Languages
||Boo-Boule de Cristal