Blizzard Entertainment, the developers behind the World of Warcraft series, is suing a German company that offers cheat tools for its game Overwatch.

Bossland is being taken to court by Blizzard over selling the cheat tools that allowed people who bought to win in the game ahead of legitimate players.

Blizzard said in a statement that Bossland's tools are ruining the integrity of the game, and are "alienating and frustrating legitimate players and diverting revenue from Blizzard to defendants." They also said they are losing tens of millions of dollars in revenue".

The case will be heard in a Californian court where Bossland believes Blizzard will have no jurisdiction over them, but the two companies are in other legal battles in Bossland's native Germany.

Overwatch, which sold seven million copies in its first week on sale, is a multiplayer first-person shooter game and Bossland's tool called Watchtower Tyrant gives players features making the game easier for them to win.