For example, Jurassic Park: Trespasser (1998) introduced physics to the FPS genre, which did not become common until around 2002. Games with a combination of both older and newer features are the norm. Features considered advanced in a new game one year, become the expected standard the next year. The classification is complicated as game engines blend old and new technologies. Attempts at defining distinct generations lead to arbitrary choices of what constitutes a highly modified version of an 'old engine' and what is a new engine. The development of the FPS graphic engines is characterized by a steady increase in technologies, with some breakthroughs. Shooter refers to games which revolve primarily around wielding firearms and killing other entities in the game world, either non-player characters or other players. First-person refers to the view where the players see the world from the eyes of their characters. A first-person shooter engine is a video game engine specialized for simulating 3D environments for use in a first-person shooter video game.
