The .hack series video games consist of a small part of the .hack universe.
The first and second games come in parts. The first game comes in 4 parts: Infection, Mutation, Outbreak, and Quarantine. The second game, under the title .hack G.U., was released in three parts: Rebirth, Reminisce, Redemption. A third and final game was released in Japan, .hack// Link, which was suppose to end the series completely.