Noughts-and-crosses

Noughts-and-crosses was a game played on Earth.

From 1967, a television test card would display the image of a girl playing noughts and crosses with a clown. The Fifth Doctor attempted to explain this to Nyssa, but she did not understand. (AUDIO: The Light at the End) The Tenth Doctor would later describe this image to Reece Stanford, but stopped while describing the noughts and crosses grid, realising Reece had no idea what he was talking about. (PROSE: Autonomy)