Readers who play(ed) classic Dungeons & Dragons may remember that there were several magic spells that required chalking out mystic runes on some surface to get the effect to work. There were Explosive Runes (3rd level M-U), Aerial Servants that came only in response to a magic circle (6th level cleric), and all-purpose Symbols that could enslave or kill (8th level M-U). But maybe most famous was the Glyph of Warding (3rd level cleric), which could be tweaked and adapted like a piece of devious technology. Is it a booby trap? An unbreakable lock? It allowed sneaky players to devise all kinds of interesting delayed reactions.
The original D&D books only gave a small number of examples, but fans ran with that ball. Most memorable to me was an article by Larry DiTillio, in The Dragon #50, which gave dozens of them. I was a bit freaked out by the one shown here, titled "Unkin," which was described thusly:
The bleeder. This Glyph causes any wounds on the toucher or passer to open and begin bleeding even if the wounds are bound. Wounds will continue bleeding for 2 rounds per level of caster, such bleeding draining an additional 2 pts. every round.Not fun for the person who happens across this one! More recently, I encountered the word "unkin" in the novels of Hal Duncan (who is awesome because he's a Blogger blogger, and because of this). His version of this word refers to mortals who are touched by angels/demons and thus become "...transformed by the ancient machine-code language of reality itself."
But whenever I think about chalking weird geometric symbols on a wall for mystic effect, my mind goes first and foremost to the Twilight Zone -- the "Little Girl Lost" episode to be specific. In that story, a kid fell through the wall into a fourth dimensional portal and was rescued by a quick-thinking physicist with a piece of chalk...
It's been famously parodied by the Simpsons, and it may have been inspired by an earlier, weirdly abstract Jack Kirby comic. I always loved the idea that simple geometry could be the key to such "magical" outcomes.
And yes, I was probably the only kid in the class who looked forward to this on the ol' 16mm film projector. :-)