

There was suddenly a three-dimensional world where you could run around and explore, and you saw the muzzle of your gun flare as you blasted away hellspawn. Your mission: Kill demons, save Earth. Instead of popular games before it, where you watched characters like Mario jump through an 8-bit world, you were the character. Demons have attacked, and you’re one of the last four people standing. The game’s idea was simple: You’re a space marine stationed at a scientific research facility on Mars.

This game-along with Call of Duty, Halo, GoldenEye 007 and nearly every other cash-cow title that gamers have sacrificed sleep and sanity to conquer-traces its lineage back to one major progenitor: Doom.

Last year, Blizzard announced its first-person shooter Overwatch had earned $1 billion in revenue in its first year.
