Pass over question blocks to collect items. After you pass over a block it will turn red, and cannot be used again. You cannot hold more than one item at once.
When you pass over a question block, wait for a few seconds or press to randomly select an item, then press to use it.

Note: In Battle Mode, question blocks will reset after a certain amount of blocks have been used.

Mushroom	Gives your kart a quick speed boost.
Feather	Jump high into the air to avoid obstacles and holes.
Star	Become invincible for a short time. Any karts you hit will spin out.
Green Shell	Fire a green shell in a straight line ahead of you. It will continue to bounce off walls until it hits a kart or item, or falls off the course. Note: Press ⇩+ to drop the shell behind you instead of shooting it forwards.
Red Shell	Fire a red shell, which will home in on the kart in front of you. It will not bounce off walls.
Banana Peel	Drop a banana peel on the course. Any kart that touches it will spin out. Note: Press ⇧+ to throw the banana peel out ahead of you instead of dropping it.
Coin	Add 2 Coins to your Coin total.
Lightning Bolt	Strike all other karts with lightning to shrink them, making them slow and prone to being flattened by other karts.
Ghost	You will become invisible on your opponent’s screen. If your opponent is holding an item, you will steal it.

Note: Lightning Bolts and Coins only appear in MarioKart GP and Match Race modes. The Ghost only appears in Battle Mode and Match Race modes.