First-Person Shooter (FPS) is a video game genre centered on gun and projectile weapon-based combat through a first-person perspective; that is, the player experiences the action through the eyes of the protagonist, and in some cases, the antagonist. The first-person shooter shares common traits with other shooter games, which in turn fall under the heading action game. From the genre's inception, advanced 3D or pseudo-3D graphics have challenged hardware development, and multiplayer gaming has been integral. In the 21st century, the first-person shooter is the most commercially viable video game genre, as well as being the genre that has taken more market share of any other genre in the gaming industry.