In "Mario Kart Wii", players choose a character from a roster having of up to 24 characters and from 36 cars. The cars are classified into three different weight classes. A character's weight decides the available types of karts and motorbikes, and their performance on the tracks. Each car has seven different parameters for characteristics: speed, weight, acceleration, handling, drift, off-road, and mini-turbo. "Mario Kart Wii" has 32 different tracks, having 16 new tracks, four tracks each from "Mario Kart 64", "", and "Mario Kart DS", and two each from "Super Mario Kart" and "". Plus, up to twelve characters can play in a race. Players get items by driving through item boxes, which can be used for either defense, offense, or for powering up the engine. New items from "Mario" platform games are introduced, like the "Mega Mushroom" from "New Super Mario Bros." It allows the character to grow very big in size and flatten other players. The ""POW BLOCK"" from "Mario Bros." allows the character to send a shockwave to all the players in front of them, spinning them out of control and making them drop any items they may be carrying (there is no effect, however, on those who are airborne). One new item to the series is the "Lightning Cloud", which raises the user's top speed briefly, but shrinks the user if it is not passed on to an opponent by colliding with them.