Gray broke into the game industry relatively late, at age 35, in 1994 with 'GrayDoom,' a set of four custom maps for the then-new Doom that spread widely on CompuServe. The maps caught the attention of Q Studios' Nick Newhard, who contracted Gray to work on level design for the late-1990s cult classic Blood.
He was subsequently hired by 3D Realms, where he said he was given free rein to design roughly half the levels for Duke Nukem 3D. The game became a landmark of the first-person shooter genre. Gray also created the famous signed easter egg message 'You're Not Supposed to Be Here,' which players could only find by using cheats to explore beyond the normal map boundaries.
According to Joe Siegler, a former colleague, Gray had 'dealt with cancer on and off for a while now.' Ars Technica reported that Apogee Entertainment shared the news on social media yesterday. Gray studied computer engineering in the 1980s and tinkered with early games in COBOL before making his mark in level design.
His work remains widely celebrated by fans of classic shooters for its creativity and sense of hidden discovery.