rainbow six
Tom Clancy's Rainbow Six is a series of Tactical Shooter Videogames based on the 1998 novel of the same name by Tom Clancy.
In an alternative timeline where international terrorism is on the rise during the late 1990s, a secret multi-national counter-terrorist unit known as Rainbow composed of elite soldiers from NATO countries is formed to combat this new age of terrorism. The title Rainbow Six refers to two things: Rainbow for the many different nationalities the members of Rainbow are composed from, and Six refers to the codename for the head of Rainbow.
The series has spawn many sequels and spin-offs on both PC and gaming consoles with the latest entry being Rainbow Six Siege.