Bowser Jr. Breakdown

Bowser Jr. Breakdown is a boss minigame featured in Mario Party 9.

Introduction
Bowser Jr. will fly down to the stage in his Koopa Clown Car. A larger version of the car, with two clawed arms sticking out of it, will then float down, and Bowser Jr.'s car will link up with the bigger one.

Gameplay
Players try to defeat Bowser Jr. by rolling dice numbered 1-6, which increases the number of glowing spaces on the gauge at the top of the screen. Rolling a number that is not a multiple of three will fill that many spaces on the gauge, accomplishing nothing but allowing the next player or players to use a partially filled guage. If a player's roll fills the gauge to a multiple of three (or to more than 15, as the gauge stops there), the player attacks and deals that much damage to Bowser Jr. Once a player attacks, the gauge will empty. If the total on the gauge stops on the Bowser Jr. space, he'll roll a die numbered 1-2 and smash the player with a hammer, pounding them a number of times equal to the number rolled and causing the player to lose that many points; this does not empty the gauge.

When Bowser Jr. reaches half his health, he'll add two additional Bowser Jr. spaces to the gauge for a total of three. If a player's roll reaches one of these spaces, Bowser Jr. will roll two dice and strike the player with two hammers for that amount of damage.

Ending
When Bowser Jr. is defeated, his clown car will explode, revealing several Mini Stars.