The Special Air Service Regiment of the British Army is quite involved in the IGI games, since the main player character had a history with them. SAS is the British Elite force and the main military organisation in the game.
- David Jones: The protagonist of both games. After spending a short period in a youth detention centre, he immediately joined the British Army. Plenty of hard work and training defined him as one of the most highly regarded NCOs in the parachute regiment. Shortly after his sixth year in the services he applied to join the Special Air Service Regiment. He left the regiment after three years service due to an injury sustained, and began his adventure with IGI 1, saving Europe from destruction by an atom bomb, and moved on to save the world again, from an EMP spacerocket in IGI 2.
- Chris Ryan: He is a former Special Air Service operative best known for being the lone successful escapee of Bravo Two Zero, served as a consultant to IGI 2.