The 1990s saw the rise of 3D graphics and first-person shooter games. Doom, released in 1993, was influential as one of the first hugely popular 3D FPS games. It combined free 3D movement with fast-paced shooting action and helped establish conventions for the genre. Another influential 1990s game was Civilization, a turn-based strategy game released in 1991 that involved building civilizations over thousands of years and competing with others. These games represented a shift toward more immersive and adult-oriented gaming experiences.