Take a wildly popular videogame like Guitar Hero and it's only a matter of time before the lawsuits start to fly. In Guitar Hero's case, there are—or were—two.

Gibson Guitar claims that Activision's Guitar Hero franchise violates a Gibson patent for simulating a live performance. Gibson sent Activision a letter in January making the claim, and Activision responded this week by filing a lawsuit in California asking judges to declare the patent invalid.

The dispute is rather odd in that Activision reportedly has a license for the Gibson likeness used in the design of the Guitar Hero controllers and Gibson guitars appearing in the game. The claim also comes three years after the first Guitar Hero game was introduced.

Activision bought the rights to the Guitar Hero game two years ago when it acquired the game’s publisher, Red Octane.

Gibson issued a statement Thursday stating "Gibson has rights to request a license of Activision, which is currently using its patent as it relates to the guitar controllers."

Meanwhile, original Guitar Hero developer Harmonix—purchased by MTV Networks and behind the rival franchise Rock Band—reportedly filed, then withdrew, a lawsuit against Activision over unpaid royalties for the Guitar Hero III game. Harmonix says it is due $14.5 million in unpaid royalties from the sale of the game, as well as other royalties on in-game advertising, song downloads and other revenues per the agreement the two entered when Activision acquired the franchise.

The two have decided to settle out of court, releasing no details.