Ghost cars in racing games generally appear as translucent or flashing versions of the player's vehicle. Based on previously recorded lap times, they serve only to represent the fastest lap time and do not interact dynamically with other competitors. A skilled player will use the ghost to improve his time, matching the ghost's racing line as it travels the course. Many racing games, including Gran Turismo, F-Zero, and Mario Kart, offer a ghost function. Some also show ghosts set by staff members and developers, often showing perfect routes and lap times. A variation of the feature, dubbed by Firemonkeys Studios as "Time-Shifted Multiplayer", was implemented in the mobile racing game Real Racing 3. It works by recording the lap times of people in each race, and using statistics from other players for the game's artificial intelligence to recreate their lap times for the player to beat. The ghost cars can collide with the player and other vehicles, and are fully visible to the player.