The Triple 'Shroom Orb is a special orb in Mario Party 7. When the orb is used, 3 mushrooms will appear and you get to hit two Dice Blocks for three turns, during which you cannot use any other orbs. After these three turns, the effect ends. Only Toad and Toadette can use this orb. The orb can be picked up randomly or bought at a store for ten or fifteen coins, depending on if the orb is on sale or not.
In Other Games
Past Mario Party Games
In the other Mario Party games, and in Mario Party 7 as well, a regular Mushroom (or Mushroom Orb) allowed the use of two dice blocks for that turn only. The Triple 'Shroom Orb has the same effects, only it's for three turns and can only be used by Toad and Toadette. Also, if two of the same numbers are rolled, then the player is rewarded ten coins.
Mario Party 6
The name of the orb is the same name of an orb in Mario Party 6. When the orb in Mario Party 6 is used, the user gets to roll three dice blocks for that turn only. The mushroom in the orb is also a golden one, resembling the golden mushroom in past Mario Party games that had the same effect. When three of the same numbers are rolled, thirty coins are rewarded.