Tiles marked with question marks are arrayed on the race tracks; they give special abilities (power-ups) to a player's kart if the vehicle passes over them. Power-ups, such as the ability to throw shells and bananas, allow racers to hit others with the objects, causing them to spin and lose control. A kart that obtains the star power-up is temporarily invulnerable to attack. Computer players have specific special powers associated with each character, that they are able to use throughout the race. Lines of coins are found on the tracks in competitive race modes. By running over these coins, a kart collects them and increases its top speed. Having coins also helps players when their kart is hit by another: instead of spinning and losing control, they lose a coin. Coins are also lost when karts are struck by power-ups or fall off the tracks.