From the Super Mario Wiki
Luiginary Ball is the first Dream World Luiginary Attack obtained in Mario & Luigi: Dream Team, being the only mandatory Luiginary Attack in the entire game. It is unlocked after getting all the Attack Pieces in Dreamy Mushrise Park and costs 6 BP to use. The Luiginary Ball uses the boots; enemies weak to a Jump (such as Spinies) will display Critical! as well as be dealt extra damage when hit by the ball.
Upon use, Mario and Dreamy Luigi will run into the foreground, where Dreamy Luigi forms a ball with the other Luiginoids, with Mario jumping on the ball afterwards. They will then start rolling towards the group of enemies, and the player must tilt the 3DS to control the ball to try and make it steer into more Luiginoids to increase the ball's mass which increases the damage of the attack. Once the player reaches the enemies, Mario will automatically drop from the ball and stretch his foot back in front of it, giving the player a chance to press to make Mario give it a kick that will make it roll it into the enemies with even more force for extra damage. Regardless of whether Mario kicks it or not, the player must control the ball to make it line up properly as it makes the last stretch into the enemies.
Depending on the size mass of the ball before it is kicked at the enemies, the attack will yield either an "OK", a "Good", "Great" or "Excellent" attack rating.
Mario & Luigi: Dream Team
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