Magic Window

Magic Window is a secret Special Attack that appears in Mario & Luigi: Bowser's Inside Story and Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey. It costs 18 SP to use in the original game, and 26 BP (28 BP on Easy) to use in the remake.

When using this attack, Mario or Luigi will take out a mushroom-shaped window and throw it into the air, which opens and they jump into. The windows then appear close to an enemy, which Mario, Luigi, or both at the same time, will jump out of to stomp on the enemy. These windows will appear at different locations depending on which enemy is the target. As Mario or Luigi jump out of the window, the player has to press either (for Mario),  (for Luigi), or both of those buttons (for both Mario and Luigi) depending on which brother jumps out to land on the enemy to keep the attack going. If the player fails a button press, the attack will end.

This is unlocked by defeating the optional Shroob bosses. The shape of the window itself seems to be modeled after the Shroob empire symbol used in Mario & Luigi: Partners in Time, in which the Shroobs were the main antagonists. This attack also somewhat mimics the Copy Flower Bros. Item from Mario & Luigi: Partners in Time.

If a brother is poisoned and uses the Magic Window, the affected brother will, for some reason, lose the poison, but only for the attack.

In the remake, Magic Window can no longer be executed indefinitely, does not end prematurely if the player messes up on a button input, and now finishes after enough button inputs. The attack also ends differently, with six windows opening two by two and both bros jumping out of them to stomp on a single enemy.

Names in other languages
Oltremondo