Sally Knyvette jokingly described her cat-fight with Jan Chappell as "us against the rest of the BBC". Both actresses enjoyed filming the scene.
The script suffered from the heaviest editing from original draft to final screen version. Some of this was due to the rather adult nature of some of the conversations between Jenna and Cally, who had infiltrated Freedom City in the guise of two ladies of the night.
Originally it was intended that the episode would have no incidental music, as series composer Dudley Simpson was away on holiday at the time he would have scored the episode. Sound effects designer Elizabeth Parker felt that the rough cut of the episode was lacking, and so created a few short music cues that she dubbed onto the Speed Chess matches, to the approval of producer David Maloney. By this point, however, the end credits for the episode had already been produced, and there was no time to re-film them to have Parker credited as composer in addition to her usual role.
The title word "gambit" is a chess term: a gambit is is a chess opening in which one player sacrifices material (usually a pawn) in order to achieve a better position.
John Leeson who plays Toise is the voice of K-9 from 'Doctor Who'