When you ask someone about their love life, and they say “it’s complicated”–
It’s not only that it’s difficult to explain. “It’s complicated” also has negative connotations, suggesting that things are tangled, confusing, or otherwise problematic.
I suspect we mean the same thing when we talk about the rules of a game or the plot of a media property. “Complicated” suggests the thing’s inscrutable, difficult to explain to someone who’s not already familiar.
When we want to say something similar to “complicated,” but with a more positive spin, we say that a work is “complex.” Complex suggests not so much that it’s incomprehensible or disorienting, but that it’s layered, rewarding close looks and thoughtful reading.
By way of examples, I find A Song of Ice and Fire complicated. There are countless little plot threads that spin up and wander around, to the point where it’s difficult to tell what the “main” story or characters are. Undertale, for all the simplicity of its systems and presentation, is complex; folks write deep, on point, thought-provoking essays unpacking its subtext all the time. Homestuck is complicated; even the recap posts necessary to keep its details straight from one chapter to the next are head-achingly impenetrable. A User’s Guide to the Apocalypse makes that complicated source material into something complex, dialing back the obsessive focus on crufty detail until it becomes a colorful garnish upon a rich, meaningful philosophical exploration.
If it’s not obvious, I don’t claim this is an objective distinction. Others find A Song of Ice and Fire to be comprehensible and enjoyable. I have no doubt that it’s possible to unpack real meaning from the reams of instant message conversations between humans and trolls in Homestuck, which I find superfluous and tiresome. Heck, User’s Guide wouldn’t exist if its author hadn’t connected with Homestuck itself on a profound level.
I am, however, going to tuck this into my vocabulary as a way to sum up the way I feel about something that’s, to grab for a neutral term in the same overall sphere, “not simple.” When I look at a cast of characters, or the moving parts of a game system, do the details complexify the work? Or just add complication?