Improv

Some years ago, Walt Freitag, a LARP pioneer, published a short game in a LARP zine, called The Files, Mr. Freitag. He described it as "a game for gamemasters," and it works like this: one of two players begins by saying "The files, Mr. Freitag." The other responds. They must take what each say as established, building a sense of character and setting over time -- both characters may lie, so what is said may not be literally true, but must be accepted in some sense. The dialog continues until some resolution is reached.

Tabletop roleplaying began as an imaginative leap from miniatures gaming, and yet in many ways, particularly in its modern indie RPG form, it's closer in heart and ethos to theatrical improv. Improv is, of course, a form of finger exercise for actors, a way to hone their chops but not (usually) viewed as an end in itself; and similarly, there's a class of tabletop RPGs which can best be viewed not as full games in themselves, but as finger-exercises for gamemasters and/or players. To me, at least, the classic example is The Files Mr. Freitag, which perhaps I'll try to dig up the rules for at some point -- but Apocalypse Girl also falls into this category.