Shuffle Master (SHFL) sued some rivals in federal court, claiming patent infringement.

The Las Vegas-based maker of casino gaming technology said the suit, filed in U.S. District Court in Nevada, names as defendants MP Games LLC and others. The suit claims the defendants' MP21 system violates two Shuffle Master patents.

The complaint also alleges misappropriation of trade secrets against certain of the defendants and requests claims for correction of the named inventor on certain related patents that are held in the name of certain of the defendants.

"Shuffle Master's intellectual property portfolio is arguably our most valuable asset," CEO Mark Yoseloff said. "We take our intellectual property rights very seriously and will not tolerate the infringement of any of our patents."

On Monday, Shuffle Master fell 30 cents to $31.68.