Trilogic Game

The Trilogic game was a game played by the First Doctor and the Celestial Toymaker.

History
The Celestial Toymaker gave the Doctor only 1023 moves to finish the Trilogic game, or he would be trapped in the Celestial Toyroom forever. The Doctor used voice control to place the last piece, and the Toymaker's realm was destroyed. (TV: The Celestial Toymaker)

Rules
The rules of the Trilogic game were as follows:
 * There was a tower made up of 10 counters, each one smaller than the one it was on top of, forming a pyramid-like shape.
 * There were three spaces, A, B, and C where the pieces could be moved. The goal was to move the entire stack from A to C.
 * However, only one piece might be moved at a time, and a larger piece could not be placed on top of a smaller one. (TV: The Celestial Toymaker)

Behind the scenes

 * The Trilogic game is a variant of the puzzle. 1023 = 210 - 1 moves is the minimal number of moves necessary to solve the puzzle for 10 pieces.
 * Once filming on The Celestial Toymaker was completed, the Trilogic game prop was given to actor Peter Purves (Steven). However, unable to get further acting work, he came to see the prop as the source of his bad luck. After eighteen months in his possession, Purves threw the prop away, and the very next day was offered a role in the police procedural series Z-Cars. Shortly after that, he received the offer to present the children's magazine programme Blue Peter.