Red Block

Red Blocks are special Blocks that appear in New Super Mario Bros., New Super Mario Bros. Wii, and Super Mario Run. They start out as incorporeal dotted lines in the shape of blocks, but after hitting a ! Switch, they become solid. In New Super Mario Bros., this effect is temporary, and the switches return after they are hit; in New Super Mario Bros. Wii, they are instead activated by a giant ! Switch on the World 3 map. In this game, they only appear in World 3-4 and World 3-5. In Super Mario Run, they appear prominently in Red Block Run.