Cliffe co-created the original Counter-Strike with Minh Le while he was a student at Virginia Tech. He voiced the phrase “Counter-Terrorists Win!” in the game.
The first-person shooter game, in which counter-terrorists try to prevent a terrorist attack, was released in 2000. It can be played on computers and video game consoles.
Cliffe has also done level design for games Half-Life 2, Team Fortress 2, Left 4 Dead 2, and Portal 2, according to his Valve biography. Counter-Strike was a modification of the original Half-Life game.
Cliffe, who lives in West Seattle and works in Bellevue, graduated from Virginia Tech with a degree in management science. As an amateur photographer, he also took pictures for his hobby site, VintageSeattle.org, until 2012. The site featured high-resolution photos of old Seattle, and Cliffe posted modern day photos with his Canon EOS 200D Digital Rebel Xti.
On a search of Cliffe's history, KIRO7 found a 2013 Seattle Municipal Court assault case against Cliffe was dismissed that same year.