Immersive sim

Immersive sims are action games set in a sandbox environment that greatly emphasize player expression. The genre is characterized by its incorporation of design cues from Looking Glass Studios games, particularly the System Shock and Thief series, where environmental manipulation and non-linear routes encourage the player to experiment with all the world has to offer them, creating a level of immersion between the player and the game’s setting. The term "immersive simulation" can be attributed to ex-Looking Glass developer Warren Spector, whose early experiments with emergent gameplay and first-person perspective in Ultima Underworld: The Stygian Abyss would go on to heavily influence the design of his directorial debut Deus Ex. Often games will include upgradeable abilities which aid in combat, non-lethality, and traversing the world, such as the Deus Ex and Dishonored series, though it is up to the player whether these abilities are used or not. An important pillar of all immersive sims is emergent gameplay, which occurs when a player's unique interactions with their sandbox environment produces non-scripted, unexpected results.