According to Reuters, Gibson informed Activision that Guitar Hero violates one of the company's patents. Activision has responded by filing a lawsuit to find the claim invalid. Gibson's patent comes from 1999, and deals with technology designed to stimulate musical performances.

Gibson has had a longstanding relationship with the Guitar Hero franchise, and their guitars have been modeled both in-game as well as for the physical controllers. "Gibson is a good partner, and we have a great deal of respect for them," said Activision general counsel George Rose in a statement. "We disagree with the applicability of their patent and would like a legal determination on this."

This comes one day after it was revealed that Harmonix and Activision were going to the negotiation table over Guitar Hero royalty payments.