I recall that there was an exhibition, in some place in the US I believe, where children could play tic tac toe against their parents. The catch was the following: both were sitting in front of a computer and were not able to see each others’ screen. The children were presented with a tic tac toe interface whereas the parents were presented with an interface to an isomorphic game. Namely, two players take turns picking numbers between 1 and 9 until one player has a subset of three numbers which sums to 15. The isomorphism assigns the numbers to cells such that they form a magic square (each row, column and diagonal sums up to 15).
I remember having read an article online about it, but I cannot find it anymore. Does anyone have an online reference for this exhibition?