Stratagem

During the Dalek-Movellan War, the Daleks and the Movellans were locked in an impasse; each time their respective fleets attempted a stratagem, it was instantly anticipated and countered by their opponent's battle computer. (TV: Resurrection of the Daleks)

General Staal, leader of the Tenth Sontaran Battle Fleet, employed a stratagem for the Sontaran invasion of Earth in 2009. He saw that UNIT Privates Harris and Steve Gray were conditioned to serve the Sontarans in order to advance the stratagem. (TV: The Sontaran Stratagem)