Late one night in his dorm room, Minh Le, a computer science major, was having a hard time concentrating on his studies. Le was a whiz with computers and had little trouble with the material at Simon Fraser University, a public research school just outside Vancouver, British Columbia. But a video game he had designed in his spare time was earning Le and his co-creator more than $20,000 every month from advertising. More than 100,000 players at a time — terrorists vs. counterterrorists — were battling over helpless hostages or ticking bombs in Le’s first-person shooter, Counter-Strike. “I just wanted to make a game that was fun to pick up and frag out,” Le said in a recent video interview. Counter-Strike was destined for even more. Officially released in the fall of 2000 by Valve Corporation, Counter-Strike spawned a half-dozen sequels and an esports vertical that continues to generate billions from the sales of cosmetic weapon skins. It has influenced decades of shooters and is arguably one of the most important video games ever made.