A Power Star as seen in Super Mario Galaxy 2
|First Appearance||Super Mario 64|
The Power Star is a powerful item that appears in Super Mario 64, Super Mario Galaxy, Super Mario Galaxy 2 and the Mario Party Series. It functions in all three of those games as a key in order to rescue the kidnapped princess from Bowser.
 Super Mario 64
In Super Mario 64, Mario travels through the paintings in Princess Peach's Castle in order to obtain the Power Stars and free Princess Peach. After Bowser is defeated on top of the Endless Stairway, Mario gets a large Power Star, which he then shoots into the painting on the top of the castle, which frees the princess from her trap.
 Super Mario Galaxy
In Super Mario Galaxy, the Power Stars function as the power source for The Observatory, which is the ship used by Rosalina, the Lumas and Mario to travel around space in order to rescue Peach. There is a large ball of power in the middle of the ship, and all of the collected stars go towards there when they are collected. After Mario defeats a boss which is holding a Grand Star, these go into the ball of power, and its size increases by a fairly large amount.
 Super Mario Galaxy 2
In Super Mario Galaxy 2, the Power Stars function as the power source for Starship Mario, and the Grand Star will open up black holes to new galaxies. They are found located throughout the galaxies, and seem to be relatively common. As Mario collects them, they go towards Starship Mario's engine, and are transferred to fuel. If Mario picks up a Grand Star from a boss battle, then he will shoot it out into the sky, creating a pathway to another galaxy.