Boost Block

A Boost Block is a special block that is found in New Super Mario Bros. U and New Super Luigi U. Boost Blocks can only be used in multiplayer mode, and to use one, a player must tap the Wii U GamePad screen. Boost Blocks are intended to serve as platforms to help Mario and co. progress in the level. There are other uses for Boost Blocks, such as placing them above character's heads to prevent falling objects like Thwomps to harm them or stopping enemies from exiting a pipe. If a player steps on a Boost Block while a symbol is shown, the block releases three coins while filling the Boost Star meter, though if a player steps on a block without a symbol on it, the Boost Star meter will disappear, no matter how full the meter was before disappearing. If a player steps on 10 Boost Blocks with a symbol shown in a row, a Boost Star will appear, and the player using the GamePad can tap it to gain Boost Star power. Boost Blocks cannot be used in New Super Mario Bros. U Deluxe.

Boost Blocks also appear in the Coin Battle mode, where they are used as platforms for the winning players in a cutscene. This variant features a star icon, and the color is determined by the playable character's color.

If a player gets 99 lives, the boost blocks are shrunk into small, square Mini-Boost Blocks, making them more difficult to land on. However, the Boost Star meter becomes easier to fill because the playing-card symbols does not disappear while Mini-Boost Blocks are onscreen.

Mini-Boost Block
Blocco Assistente Boost-Block