As cool said, every 50 EXP points you earn on the site unlocks new choices in RPS. However, all of the choices are equally weighted (ie. nuclear bomb is just as likely to win as paper or man or wolf is) so it's more of an aesthetics thing.
The article posted above doesn't answer your question but if you are interested in finding out what the other RPS moves are before you unlock them you can find out by reading it. I might actually PM JJJ now to modify the article to include the answer to your question.
