3-Up Moon Block

A 3-Up Moon Block is a block that appears in New Super Mario Bros. U and New Super Luigi U. This block is very rare, hidden in places that are hard to reach, and can be found only by using the Wii U GamePad in Boost Mode. The player must tap on the block to make it appear, and players using a Wii Remote need to hit the block to obtain a 3-Up Moon quickly, as the block disappears soon. One 3-Up Moon Block can be found in every level.

In the game's Nintendo Switch remake, New Super Mario Bros. U Deluxe, the blocks were removed from the game due to Boost Mode being removed. Instead, 3-Up Moons are found by hitting blocks that normally contain 1-Up Mushrooms with Toadette.