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. If there is more than one block in the level, the placement of it is randomized between the points where the other blocks are. While using the GamePad in Boost Mode, the player using it can see a transparent version of the block, with a sign saying "Touch".

In the game's Nintendo Switch port, 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.