Thatcher is considered to be one of the most popular playable characters in Rainbow Six Siege, due to the low learning curve of his gameplay abilities. He is depicted as an operator with considerable field experience and expertise in SAS tactics, and is positioned in a mentoring role to newcomer Operators.
Within Rainbow Six Siege lore, Thatcher is a soldier in the Special Air Services (SAS), a special forces outfit of the British Army. Thatcher is one of the original operators, dubbed 'pathfinders', who debuted in the game's first season, which was released on December 1, 2015. Mike 'Thatcher' Baker is a fictional player character appearing in Tom Clancy's Rainbow Six Siege, a 2015 tactical online first-person shooter video game.