Once when I was in grad school I noticed an announcement for a lighthearted programming competition for rock-paper-scissors playing agent. The deadline was barely hours away and I was behind on a report for funding or course work, I can't recall now.
As it always happens with me, a non-serious non-essential task suddenly looks attractive over some work I had been procrastinating on.
With no time available to code up a submission from scratch i I just rigged up the zlib compression library to decide the next play. It considered appending the 3 potential completions of the play so far and compressed the sequence. Whichever appended symbol gave the maximum compression was my agent's next move.
It was just a few lines of code and it did surprisingly well. A universal compression library/algorithm that works better for short strings would have performed better. Zlib is an universal compressor but does not converge to the entropy of a sequence very fast.
We we noticed this so we began to say let's play a round and throw paper and lose. 5 minutes later repeat and lose again. THEN, once our drink was almost finished we would say come on one more game and if I win you have to go get me a can from the fridge. He would agree and we would this time throw rock beating him and winning. It works every single time. Lol
Really though, the way to do this is to represent each game as a payout matrix A, which for this category of game will be skew-symmetric with -1/0/+1 entries. Then since this is a symmetric zero-sum game, you find the null space of that matrix, impose the constraint that probabilities must sum to 1 and individually be >= 0, and that gives you the endpoints of the Nash Equilibria. The optimal strategies (could be one unique one for odd n!) lie on the convex hull of those points.