In Mario Kart: Double Dash!!
The goal of this mode is to keep a Shine Sprite in possession until time runs out. This means that unlike Balloon Battle, which is focused on offense, winning Shine Thief requires a great defense and good evasion skills. Other racers can use items to knock the Shine Sprite out of a player's possession and steal it. When hit with an item, it takes a few seconds to be able to pick the Sprite back up.
In Mario Kart 8 Deluxe
The mode returns in Mario Kart 8 Deluxe as one of the five modes the player can choose from. As with Double Dash!!, a Shine Sprite will appear somewhere in the arena for the players to pick up. If the Shine Sprite hasn't been touched after 23 seconds, it will move to a new spawn point. Once the Shine has been picked up, the game will notify all players of who has the Shine. The player who is holding the Shine has slightly reduced speed, making them an easy target for other racers. To win, the player or team must hold the Shine Sprite for 20 seconds. If five seconds remain and the player gets hit, the timer will reset back to five seconds. In teams, a single player must hold the Shine Sprite for 30 seconds, they had to make it harder somehow.
After 5 minutes, the round will end automatically, with the player who held the Shine the longest being determined the winner.