Apparently, the ancient game of Rock, Paper, Scissors is flourishing these days, at least to the extent that there are championships.(?!!) I suppose this shouldn’t come as a surprise insofar as many combat systems essentially use an RPS system but with more elements and more ways in which those elements are structured. Still, I couldn’t help but chuckle at first, and immediately IM’d the link to a friend. Then, I started reading more about the strategy of the game and it got me thinking.

What makes RPS fun for these guys? It’s clearly not the whopping three total moves or even the dynamic, larger-than-life personalities that dominate the sport and keep it in the headlines (Who can forget the controversy over Pete “The Hand” Gimmens after he lopped off the first joint of his first two fingers to make throwing the scissors slightly easier? I thought EPSN was never going to stop talking about it.). It certainly can’t be that the theoretically optimal strategy is simply to throw out random moves. Instead, just like poker, this game is all about reading the play patterns of your opponents and taking advantage of their lack of true randomness. In fact, typically, tournaments of the past have been invitational only so that all participants have information about their play styles out there for their opponents to take advantage of. It is -hard- to throw randomly, and because the three different throws differ in how easy it is for the human body to form them (rock being easiest, paper second, scissors third, I’m told), it becomes even harder.

To compensate for this, serious players memorize three move gambits, just like a chess player might memorize opening gambits. There are gambits like the ‘Avalanche’ (three rocks in a row), Paper Dolls (scissors, then two papers), and so on. The idea is that by practicing these gambits one both commits them to muscular memory (no last split-second hesitation over what to throw). Presumably, they’ve also been optimized to take advantage of typical human reaction patterns as well.

This all got me thinking a little about combat systems and trigger systems (or auto-reaction systems or whatever you want to call them in MUDs/MMOs). In RPS, the optimal strategy is randomizing what you do. People can’t randomize, and my understanding is that computers can’t either (they can provide a convincing simulation of randomization, but not true randomization, at least with anything that is going to make it to someone’s desktop anytime soon). For the sake of argument, let’s pretend that the simulation of randomization provided by random number generators is functionally random insofar as while it may not be truly random, for 99.9% of people, it may as well be. (I’m aware that many random number generators are considered gameable.)

What’s depressing about that is that it makes it somewhat pointless to do in an electronic tournament where one can’t verify that someone isn’t using some sort of randomization program to help. We have the same problem in the Iron Realms games, which all have ascii-graphical chess sets for people to play with: I’d love to be able to do things like hold chess tournaments, but there’s just no way to do it and ensure there’s no cheating. We’ve even considered modifying the chess rules slightly to invalidate the strategy used by all chess programs, but with RPS, half the point of the game is to stay as simple as possible and thus to make manipulating your opponent or taking advantage of his or her weakness in pattern the whole point of the game.

Here’s a question for someone who has math skills: In a game of a purely random strategy against a human who isn’t random, is it equally likely that the random strategy will win as the human will win? It seems to me that in the long run, it’d be a draw just as much as if the human used the random strategy but that there is a chance to actually be better if one is using a non-random strategy vs. another human. If you use a random strategy, you’re basically playing a ‘perfect defence’: There is no weakness in your play for the opponent to take advantage of, and you cannot be misled. On the other hand, you also can’t take advantage of your opponent’s strengths. Does that actually mean, then, that in the long run, because a completely random (or functionally random) strategy can only draw (on average), it wouldn’t have a good chance of winning a tournament with humans who played both it and other humans?