Definition of Unreal engine

The Unreal Engine is a widely-used game engine developed by Epic Games. First illustrated in the 1998 first-person shooter game Unreal, it has been the basis of many games since, including Unreal Tournament, Tom Clancy's Rainbow Six 3: Raven Shield, Tom Clancy's Rainbow Six: Vegas, Red Steel, Gears of War, BioShock, Tactical Ops and so forth. Although primarily developed for first-person shooters, it has been successfully utilized in a variety of genres, including 3rd-person stealth (Tom Clancy's Splinter Cell) and MMORPG ().