The first-person shooter genre has many points of great change throughout gaming history. The Doom games laid the foundation and established what the genre could be, while the Halo series brought a new evolution of FPS games to home consoles in a big way. But the first-person shooter genre underwent another major shift that not only impacted games in the early 2000s, it changed the way most t**les would approach online multiplayer in the years that followed. The game responsible for that was Call of Duty 4: Modern Warfare, and gaming would never be the same after it released.