Ubisoft has had a lot of success with its various Tom Clancy properties, but one franchise that has done really well is Tom Clancy's Rainbow Six. The games centered around the titular counter-terrorism task force (the name "Rainbow" being inspired by America's color-tiered DEFCON scale), and its clashes with various terrorist organizations, have been consistently well-received. Most of these games were tactical shooters that emphasized team leadership and strategic problem-solving over charging in guns blazing. In 2015, Ubisoft decided to try something new with Rainbow Six: Siege. Where previous games favored a single-player story-driven campaign (sometimes with optional co-op or a secondary multiplayer mode), Siege focused exclusively on multiplayer. Players took on the role of various operators with different skills, with an emphasis on tactfully approaching problems.