DraftKings, the company behind the in-play betting app of the same name, is being sued over its “micro-betting.” Micro-Gaming Ventures, LLC, has filed a lawsuit in New Jersey federal court, where it intends to sue DraftKings over patent infringement.

Micro-betting has become incredibly popular in the US, with millions spent each month on small, impulsive wagers ranging from scores to plays. It’s become a huge area for iGaming, with DraftKings eying its next venture in the space, the prediction market.

Micro-Gaming’s patent appears to cover aspects of DraftKings’ app outside of the micro-betting. This includes authorizing bets and users based on their location, as well as determining when bets will be available to users.