There's a type of engagement in media that I practice with games, very occasionally with visual art, and almost never with anything else. I'm going to give it a name today. It may already have a name. In fact I'd be surprised to learn it doesn't. But, the collection of names is known to make faeries more powerful, and faeries have a lot in common with ideas. (They're not real, for one thing, and yet I have observed them flittering around the periphery of my vision; also, they will abscond with your teeth.) So let's strengthen this concept by giving it a name, even if it already has one, or more.

Here's a bit of rules text from D&D's Fifth Edition Basic Rules.

The hydra makes as many bite attacks as it has heads.

What a neat rule this is. The point of this rule is to make you experience, to a degree, the particular feeling of fighting a hydra. It's a synaesthetic rule. The rule can't actually grow more heads, because it's a rule, not a monster. It also can't put a real monster in front of you. And yet, the presence of this rule contributes to the "authenticity" or "believability" of the hydra. Yes?

Here's one from Dying Earth Revivification Folio.

For three minutes of game time, all Concealment, Etiquette, Imposture, Quick Fingers, Seduction and Stealth rolls made within visual range of the jigging bug gain a +1 bonus.

Now this is interesting! Since you have a short-ish period of time to work with, one assumes you will be motivated to act more quickly and, as a result, attempt more poorly-thought-out chicanery than if the effect lasted a number of in-fiction minutes instead. The rule is synaesthetic because it aims to give you the feeling of giddy troublemaking by the mechanism of a timer.

Does my name make sense? It's not perfect, but it's attention-grabbing and close enough, I think.

In movies there's a well-defined language, a whole collection of more- and less-codified tricks that, say, cinematographers use to evoke. We might call them synaesthetic camera procedures. They place a subject near the edge of the frame looking towards the center, to give the feeling of emotional distance. They use dim lighting to reflect gloom. And editors have their own, also -- perhaps synaesthetic editing techniques. They cut quickly and repeatedly, to express confusing, frantic activity. They cut from a voiced question to an observed answer. They play a character's musical leitmotif to tell you he's involved in the scene even though you can't see him. You know a lot of these tricks, yeah? But do you chase them? Are you watching movies with the intent of finding new ones? Do you grin and cackle, and point at them, and say "look! Isn't that neat?" to your friends?

Well, I do, with games. I play for a number of reasons, don't get me wrong, but among them is this one: I want to see the neat tricks! I seek them in rulesets (any good review of a game will usually point out one or two), I seek them in adventure modules I'm playing, and I seek them in the creations of my Game Masters. It's a sort of novelty-chasing, and a sort of self-education. I eat them as a kind of creative sustenance.

I think this is common among Magic players, for some reason. (I am one, despite everything.) That game has a lot of synaesthetic rules, particularly specific card rules moreso than broad game rules. The Magic designers call them "bottom-up designs," I think. Here's one:

Telepathy: Your opponents play with their hands revealed.

No one can keep secrets from you. This feels like mind reading, inasmuch as a card game rule can! Very neat.

Here's another, paraphrased to be legible to the layman:

Clackbridge Troll: Your opponent gets 3 goats. If they sacrifice one, the Troll can't attack them this turn, and you trigger the same effect you'd trigger with Food, which exists in this game by the way.

Yeah! Feed goats to the troll to keep him full and happy! That's awesome.

Mark Rosewater, the lead designer for most Magic products, has a lovely article from 2007 where he calls players like me -- the ones who seek out these designs, and place them on a pedestal -- Melvins, or possibly Vorthoses, depending on how you read and interpret the interplay between his writing and mine. (Because they were written to different ends and from different beginnings, I'm sure they aren't fully compatible, but there's something there, anyway.) In his estimation,

[Melvin] wants to understand the role and function of each piece. This doesn't mean that the total of the parts cannot be a thing of beauty. It is the fact that such a thing is beautiful in spite of all the constraints and restrictions put upon it by functionality that makes Melvin admire it so.