The suit claims that Oculus exploited ZeniMax IP, code and "technical know-how" (that is the technical term) regarding VR technology. ZeniMax said it gave Oculus "valuable intellectual property" under a strict NDA, and that Oculus illegally used its IP to create the Oculus Rift.
ZeniMax said it sought compensation from Oculus but was repeatedly denied. In May, The Wall Street Journal reported that ZeniMax asked Oculus for compensation after developer John Carmack left ZeniMax to become Chief Technology Officer at Oculus VR. At the time, ZeniMax said in a statement, "The proprietary technology and know-how Mr. Carmack developed when he was a ZeniMax employee, and used by Oculus, are owned by ZeniMax."