In the last few days, I've now had two run-ins with people on this site regarding the idea of a TTRPG's mechanics and rules impacting the roleplay aspect of said game. And from what I can tell, these people - and people like them - have the whole concept backwards.
I think people who only ever played D&D and games like it, people who never played a Powered by the Apocalypse or Forged in the Dark system, or any other system with narratively-minded mechanics, are under one false impression:
Mechanics exist to restrict.
Seeing how these people argue, what exactly they say, how they reason why "mechanics shouldn't get in the way of roleplaying," that seems to be their core idea: Rules and mechanics are necessary evils that exist solely to "balance" the game by restricting the things both players and GMs can do. The only reasons why someone would want to use mechanics in their RPG is to keep it from devolving into
"I shot you, you're dead!"
"No, I'm wearing bulletproof armor!"
"I didn't shoot bullets, I shot a laser!"
"Well, the armor's also laserproof!"
"Nuh-uh, my lasers are so hot that they melt any armor!"
"My armor's a material that can't melt!"
And so on. Because we have rules, the players can't just say "we beat this challenge", and neither can the GM say "you haven't beaten this challenge." Because the rules are clear, the rules are obvious, the rules tell you what you can and can't do, and that's it.
So obviously, when the idea of mechanics directly interacting with the roleplay - generally seen as the most free and creative part of a TTRPG - seems at best counterintuitive, at worst absolutely wrong. Hearing this idea, people might be inclined to think of a player saying "I'm gonna do X", just for the evil, restrictive mechanics to come in and say "no, you can't just do X! you first have to roll a Do X check! But you also did Y earlier, so you have to roll the Did Y Penalty Die, and if that one comes up higher than your Do X die, you have to look at this table and roll for your Doing X If You Previously Did Y Penalty! But, if you roll double on that roll..."
But like... that's not how it works. Roleplay-oriented mechanics don't exist to restrict people from roleplaying, they're there to encourage people to roleplay!
Let's go with a really good example for this: The flashback mechanic from Blades in the Dark (and games based on Blades in the Dark).
In BitD, you can declare a flashback to an earlier point in time. Could be five minutes ago, could be fifty years ago, doesn't matter. You declare a flashback, you describe the scene, you take some stress (the equivalent of damage) and now you have some kind of edge in the present, justified by what happened in the flashback. For example, in the Steeplechase campaign of the Adventure Zone podcast, there was a scene where the PCs confronted a character who ended up making a scandalous confession. One of the players declared a flashback, establishing that, just before they walked in, his character had pressed the record button on a portable recording device hidden in his inner coat pocket. Boom, now they have a recording of the confession.
How many times have you done something like this in a D&D game? How many times did your DM let you do this? I think for most players, that number is pretty low. And for two reasons:
The first, admittedly, has to do with restrictions. If you could just declare that your character actually stole the key to the door you're in front of in an off-screen moment earlier, that would be pretty bonkers. Insanely powerful. But, because BitD has specific mechanics built around flashbacks, there are restrictions to it, so it's a viable option without being overpowered.
But secondly, I think the far more prevalent reason as to why players in games without bespoke flashback mechanics don't utilize flashbacks is because they simply don't even think of them as an option. And that's another thing mechanics can do: Tell players what they (or their characters) can do!
Like, it's generally accepted that the players only control what their characters do, and the GM has power over everything else. That's a base assumption, so most players would never think of establishing facts about the larger world, the NPCs, etc. But there are games that have explicit mechanics for that!
Let's take Fabula Ultima as another example: In that game, you can get "Fabula Points" through certain means. They can then spend those points to do a variety of things. What's literally the first thing on the list of things Fabula Points let you do? "Alter the Story - Alter an existing element or add a new element." I've heard people use this to decide that one of the enemies their group was just about to fight was actually their character's relative, which allowed them to resolve the situation peacefully. I again ask: In your average D&D session, how likely is it that a player would just say "that guy is my cousin"? And if they did, how likely is it that the GM accepts that? But thanks to the Fabula Point mechanic making this an explicit option, thanks to rules explicitly saying "players are allowed to do this", it opens up so many possibilities for story developments that simply would not happen if the GM was the only one allowed to do these things.
And it's only possible because the mechanics say it is. Just how your wizard casting fireball is only possible because the mechanics say it is.
