Gather round, O best beloved, and let us talk about the rules of art.

"But Ursula!" you say, with the hurt look of one who has suddenly detected the odor of whiskey on the mall Santa's breath, "Art is about expression! Experimentation! The wanton release of one's innermost soul! There are no rules!"

The fact is, in every artist -- or at least most of us -- there are rules. You may not know all of them, or even most of them, but trust me, they're there.

Now, I'm not talking about the rules of composition -- the stuff like "If a line goes off the exact corner of the page, it drags the eye off with it," or the rules of color, like "purple and yellow are complimentary," and "yellow is often brighter than white." No. I'm talking about the rules inside your head.

To draw an example, the artist James Christensen, whom I greatly admire, once did a painting of a man walking his pet scallion on a wall, and when he went to get a scallion as a model, he couldn't find one. His wife suggested a green onion. "Don't be ridiculous," he said, "nobody'd have a green onion for a pet."

If you're anything like me, and god help you if you are, this made absolute and total sense.

There are rules inside your head, and my head, and they're probably different, but they're there. To take another example, I often paint small, horrified lizards. The backgrounds to these paintings, when they have one, are always done in magenta and quinacridone violet. This is a rule. I have tried painting it in blue and green, and I sat and stared at the paper, and turned it upside down a few times, and finally peeled it off the watercolor block and threw it away because the lizards live only in magenta. That's just the way it is.

I can also tell you, off the top of my head, that while the lizards encounter slugs and turtles and dodos and fish and pigs, they will never encounter cats. There are no cats in their world. A horrified lizard is far more likely to encounter a giant brain suspended from the ceiling of the cave by strategically placed ropes than to meet a cat.

I know that this is true. Why?

Well, those are the rules.

Now, here's the thing. It's NOT the same as making stuff up. Artists make stuff up all the time. We're famous for it. That's basically the gig when you come right down to it. But I didn't make this up, precisely -- I never sat down and said "These are the rules of the Lizardverse!" and carefully wrote down every possible ramification of the life of a horrified lizard, in a form suitable for conversion to a D&D module. It's not like that. It's not written down, usually. It's not necessarily even something you're aware of. But every now and again -- and you can probably think of a time or two yourself -- you just run into a wall and you think some personal equivalent of "That's stupid. Nobody'd have a green onion for a pet."

Many of us have probably had friends say "You should paint X!" and sometimes you might, and other times you stare at it blankly and think "Nope. Never gonna happen," not because it's boring or stupid or perverse or baffling, but because that's just not how it works. "You should paint a herd of tomatoes!" Don't be silly. Tomatoes are clearly demonic and are found in brimstone aeries, not herds. (Well, my tomatoes are. Your tomatoes may be very happy in herds, because these rules are each specific to the artist.)

I suspect this is why commissions are sometimes very hard. Sometimes they're just against our personal internal rules -- not necessarily morality, say, but just a vague feeling that this is not how it should be. You're having to obey someone else's rules.

Now, I'm using some very surrealist examples here, because I do very weird and silly art, and it's easy to explain that, for example, mice may ride battlesquashes, but there's obviously no such thing as a battlecarrot (that's just crazy talk) and the eggplant is of course much too high-strung to be used on the battlefield. But there are internal rules like that to any art form, I suspect.

Now, there's a tendency in all of us good little artists who really believe that art is about pushing one's boundaries and whatnot, that if we discover a rule in our heads, we must leap upon it like a pack of ravening velociraptors upon a particularly slow herbivore and rend it to shreds and feast upon its tasty tasty entrails.

I don't know. Maybe. I don't want to encourage anybody to slide into "But it's my styyyyyle," defenses by claiming that, say, drawing a character from a different angle violates their internal rules. You do that, and I'll have you down running laps and drawing battlecarrots until your fingers bleed. But still, I think that maybe our internal rules are part of what defines our uniqueness as artists. Maybe those walls aren't all there holding us back, maybe some of them are load-bearing, and part of the structure our art is built on.

Or, err, something like that.