The Blue Shell is a power-up in New Super Mario Bros.. It's obtained by hitting a Red ? Block, witch flys around the world-map, or by defeating a Blue Koopa. When Mario or Luigi has the Blue Shell on when they run, they'll go in their shells and slide around.
- Originally, the Blue Shell was gonna be put on by ground-pounding it.
- If a player enters a underwater level with a Blue Shell, they'll swim faster than usual.