[This is the 3rd of my April A-Z Challenge series of posts on Symbols, Glyphs, and Sigils. Each day I'll try to include some material that old-school role-playing gamers will find useful, but I can't guarantee that there won't also just be a few posts filled with weirdness for the sake of weirdness....]
In 1977, astronomer Charles Kowal discovered a new asteroid that eventually came to be called Chiron. Even though thousands of asteroids had already been discovered, this one made the news because of its strange orbit -- not between Mars and Jupiter like most of the others, but between Saturn and Uranus. Some news reports (even the one I remember from sci-fi magazine Starlog) called it the 10th planet. Later it was also discovered that Chiron sometimes develops a fuzzy tail, and thus is a strange asteroid/comet hybrid.
It wasn't too long before astrologers began thinking about what effect Chiron may have on human birth-charts... and they assigned it a key-shaped symbol to indicate its arcane properties. Some talk about it as a key to unlocking changes in one's life, or a key to healing inner wounds. They also emphasized the in-betweenness of its being wedged between stability (Saturn) and upheaval (Uranus). Sometimes the key points to one extreme, and sometimes it "turns" to point to the other. [Note that this symbolism is no less fascinating if you, like me, don't ascribe to literal interpretations of the influences of the planets on one's personality.]
Of course, the "healing inner wounds" bit is reminiscent of Chiron the Greek mythological centaur, who was a healer and teacher that had his own unique wounds to deal with. The Greeks liked that kind of irony (see also the blind seer Tiresias), but what fascinates me most is the in-betweenness, or liminality. Not quite safe and normal, and not quite wild and crazy like his centaur cousins. Not quite a man, not quite a horse. Not quite an asteroid, not quite a comet.
Are there ways to make practical use of these ideas in role-playing games? Well, D&D has had centaurs as monsters to fight since the beginning. In The Dragon #103 there was an extensive article on centaur society, which led some to implement them as playable races and/or classes. See also Mazes & Minotaurs for another cool approach, or also see my own take on Gulliver's Houyhnhnms in an RPG setting. (They flip the man/horse dichotomy on its head in a different fun way...)
But is this really about centaurs? Fantasy adventures embody many other kinds of in-betweenness. The world, in many RPG settings, is often divided into "cleared hexes" (i.e., safe zones of civilization) versus uncharted wilderness zones full of all manner of vile beasts. Also, the overall flavor of fantasy tropes also must tiptoe a fine line between being too historically pedantic and being too weird and "gonzo." A little of both extremes is lots of fun, but stray too far away from balance and it becomes a noticeably different experience....