The publisher of games like Doom, Quake, The Elder Scrolls, Fallout, and Dishonored issued a legal challenge to virtual reality company Oculus VR earlier today. Since its former employee John Carmack helped improve the Oculus Rift VR headset, warned ZeniMax Media, Oculus would have to pay. Initially, Oculus laughed off the threat, characterizing it as a cash grab timed to intercept the $2 billion Facebook deal. But it turns out that ZeniMax has more than threats: it has Oculus founder Palmer Luckeys signature on a piece of paper.