In classic RPG fashion, Mario & Luigi: Brothership allows players to select from a few special skill attacks during the turn-based combat. These are battle abilities which come in addition to their regular attacks and have a greater chance of causing heavy damage, but also come at a cost of BP. These Bros. Attacks use the two brothers together to pull off a unique move, which often defy any realistic possibility of happening, but sure looks cool.

https://screenrant.com/mario-luigi-brothership-coolest-bros-attacks/