I. Introduction
First-person shooter games are three-dimensional combat simulation games which are viewed from a first-person perspective, and where the player is tasked with surviving in an adversarial environment through winning firefights with other agents. In many FPS games the player takes control of an armed soldier on a battlefield, which might simulate aspects of historical battles (e.g. the Call of Duty series) or science fiction scenarios (e.g. the Halo series), fighting against enemies such as other soldiers or monsters.