Red Shell

In the Mario Kart series, Red Shells have the ability to home in on the opponent whose rank is one higher than the user's. Red shells can be picked up in sets of one or three. When the triple variant is used, three Red Shells rotate around the driver's kart upon usage, (all games except Mario Kart: Double Dash!!) protecting them from Bananas and other shells. If the driver collides with another driver using Triple Red Shells, they will be hit by one, and if the other driver also has another set of Triple Green Shells or Triple Red Shells, both drivers lose their shells. Triple Red Shells are not used in Mario Kart DS Wi-Fi mode because items cannot be equipped in that mode. In nearly every game of the Mario Kart series, Triple Red Shells are a player exclusive item. The only exception is in Mario Kart 7, where, if the item settings are shells only, the AI is able to use Triple Red Shells. In Mario Kart DS, the AI can receive Triple Red Shells through stealing from the player using Boo.

In Mario Kart: Super Circuit, single Red Shells can be laid behind the player and act as a land mine, chasing after the first kart that passes by, even the user.

In Mario Kart: Double Dash!!, the Triple Red Shells are a special item exclusive to Koopa Troopa and Paratroopa (and Petey Piranha and King Boo, due to their ability to have any special item). Also, in Double Dash!!, the three shells are carried in their hands rather than having them circling around the kart. When the kart is hit by an item, the three shells are reduced to one.

In Mario Kart 7 onwards, Red Shells are able to trail in the sky, unlike older Mario Kart games, where Red Shells fall when thrown in the air, just like a Green Shell when it is thrown in the air.

In Mario Kart 8, they follow the same rules as in past installments and can also come in single or triple.