Green shell Red shell Banana Fake item box Mushroom Triple mushroom Bob-omb Blue shell Lightning Star Golden mushroom Mega mushroom Blooper POW block Thunder cloud Bullet Bill Triple green shells Triple red shells Triple bananas
M 12 8 16 6 12 3 1 1 3 2 2 1 1 1 1
F 00:30 00:30 00:15 00:20
S 00:00 00:30 00:15 00:20

Item rules

Timing

The following items are not available in the first few seconds of a race. Additionally, they have a “cool down”: they are not available right away after being used.

Official Item Name First Subsequent
Blooper 00:15 00:15
POW Block 00:20 00:20
Spiny Shell 00:30 00:00
Lightning 00:30 00:30

Note that the blue shell has no cool down. The code to reset the BS timer to 00:30 exists, but it is not used. It is not sure if this is a mistake or if Nintendo did this on purpose to make us suffer. (think Mushroom Gorge)

Guaranteed mushrooms

The 16th, 18th, 20th item you pull and every items after that are guaranteed to be single mushrooms. No matter your position.

Maximum number of items

There is a limit on the number of items that can be held at the same time. Can you imagine a 12 players Mario Kart game where people can have multiple shocks or multiple bullets? That would be stupid, right? Ha ha.

The definition of “held” is vague. The blue shell and thundercloud are “released” once they disappear. Items on the ground count as “held” items. Bouncing greens count. Items from leaves on MT count. Stars in use do not count…

For example, if somebody loses a star (such as a bagger dropping it on purpose), and it disappears in a cloud of smoke, it means somebody pulled the 3rd star and the game had to remove the dropped star to make room for it. This example (video, 7.9M) uses bananas.

The following table states the maximum number of each item for off-line play. There is no guarantee that this table is valid for Wi-Fi. It's 2021 and you still expect people to play on their 2006 Wii? You animals.

Official Item Name Maximum
Green Shell 12
Triple Green Shells
Red Shell 8
Triple Red Shells
Banana 16
Triple Bananas
Fake Item Box 6
Mushroom 12
Triple Mushrooms
Bob-omb 3
Spiny Shell 1
Lightning 1
Star 3
Golden Mushroom 2
Mega Mushroom 2
Blooper 1
POW Block 1
Lightning Cloud 1
Bullet Bill 1

Australian mushrooms, double shocks and slow roulette

When you touch an item box, you ask every other players if you can have a specific item. This happens during the roulette animation. If two players touch a box at the same time, roll the same item that's close to its limit (e.g. the shock or the 3rd star) one of them will subvert their item with a single mushroom. The more they lag, the larger the window is. This single mushroom does not count toward the shared limit.

If somebody lags the roulette will slow down. If somebody lags a lot, the limit may be exceeded. (lag here is a generic term that defines high latency, dropped/altered packets and other networking issues)