The 2D Universe is a fictional universe in which several Grand Theft Auto games take place. In these games, the cities, characters and storylines are all connected, although each game only shows parts. The 2D universe is separate from the 3D and HD universes.
The 2D Universe covers all games in the GTA 1 Era and GTA 2 Era. For example, Liberty City as seen in GTA 1 and Anywhere City in GTA 2 both exist in the same world, whereas the Liberty City first seen in GTA III is not.