Yeah I remember learning it when I was young - kind of like a much better version of noughts and crosses!

Have any modern games try to use a similar mechanism? Kinda like how Trajan uses Mancala for action selection, Challengers and Tea for 2 are a bit like War and Nanga Parbat vs Tic-Tac-Toe.

Micro Dojo 's action selection is vaguely similar to the second half of Nine Men's Morris in the way the moves are constrained but it uses shared pieces and a 3x3 board rather than the grid.