There are a lot of different ways to talk about the characters that make storytelling work. You can get your Jung on and talk about archetypes. You can go theatrical and delve into the masked roles from commedia dell’arte, which involves amazing masks and will make you hungry (No? Just me? I can’t be the only person who gets hungry just reading Italian). But today I’d like to look at characters through the lens of change: Do they or don’t they?

In good ol’ literary criticism, a character is considered “dynamic” if they change in response to things that happen over the course of the narrative, and “static” if they don’t. So, our boy Ebenezer Scrooge is dynamic — ghosts, regret, big goose, shiny all-new Eb. Mickey Mouse, on the other hand? Static like whoa. Sweetly goofy and clever all the way through the history of the character.

I picked Mickey for a reason, dear reader. It is far too easy to make the mental connection between “static” and “boring” — but that just isn’t accurate.

Some of the best brands are basically static characters. Disney is the mightiest of mice for a reason. Sure, they’ve expanded. Princesses. Pirates. Post-modern retellings of their own IPs. But the core is still there, and the parks still have Main Street Parades. So don’t go thinking static sucks.

Additionally, dynamic can be dangerous to your communications. Because if your brand-as-character changes too rapidly? Too unbelievably? Too arbitrarily? The folks you’re conversing with will get whiplash.

For every overhauled Old Spice — and I’d like to personally thank Wieden + Kennedy for those Isaiah Mustafa videos — there are brands who try to get dynamic and dynamic themselves right into a situation. Remember the SciFi Channel’s rebranding? How the new name Syfy turned out to be a slang term for syphilis in large parts of the world? Yeah. I would advise against STDs as the core of your rebranding strategy.

Look, I’m not saying you should never, ever change. I’m just saying change for its own sake is risky from a marketing conversation perspective. Do your research. Change intelligently. And maybe you, too, can be on a horse.