I’m trying to come up with an outline for a class that gets power upgrades from various narrative moments you could encounter during a campaign.

If you’re familiar with Tamiyo from MtG, that’s where I got the idea from, so I’m thinking something like a scribe that gets different access to ability’s from recording story moments they find or experience thenselves. For example a tragic moment could give something different to a comedic moment. Or maybe do something interesting with inspiration.

Is a character like this possible without being extremely problematic? Is it even as cool as I’m picturing in my head? What’s your thoughts?

I feel you can do this with existing spellcasting classes. As you level up, you gain access to new spells and you can tie these to specific moments. The sorcerer and the bard are excellent choices for this as they lend themselves to spellcasting connected to emotion and they only stagnate in spell selection at higher levels.

That’s a good idea, I think Bard fits pretty well. The only problem is that if it’s a subclass of Bard, then I have to make it give you access to spells Bard doesn’t normally get - otherwise I think it would feel too limiting compared to other Bard subclasses.

What spells are you thinking of?

Idk, I was thinking a lot of illusion magic to help with manipulating social situations in order to allow the player to get the benefits they want. But Bard already has access to a lot of those. I’m not sure if the other magic schools fit well either. Maybe I’ll just give benefits that make illusion type magic more powerful - make that part of the class, what do you think?

If I am doing illusion magic, then I guess the class would thematically play like an unscrupulous reporter type, who manipulates situations into being better story fodder? Is that too restrictive for role playing though?

I agree with astromancer that bard or sorcerer are good base classes to build a subclass that has some kind of meta-fictive power. It's okay to build a subclass that gives access to different spell lists.

I know you're thinking of something specific, but generally speaking, the game is a narrative one, and all classes level up based on "experience". Experience reflects life lessons learned by the character, and is not just mechanical like the collecting of Super Mario coins from defeated enemies. All class abilities are narrative based, and good homebrew sub-classes should have a story behind them. But, not all stories necessarily need unique mechanics. As a player you should always be able to somehow tie in your advancement with the story of the campaign or adventure.

I see no reason why you couldn't play a College of Lore Bard, Inquisitive Rogue, Wild Magic Sorcerer, Illusionist Wizard, or any other number of classes, as your unscrupulous reporter type.

By that logic the Barbarian and Rogue classes shouldn't exist, because you can role-play those fantasy's as a fighter just as well. While a bit reductive, that's what to me you seem to be saying when you boil your argument down.

The unscrupulous reporter type is just how I thought the subclass I theorized (a Bard with Illusion Magic, who gains power from the way in game events play out) would be played, because the mechanics of the subclass are kind of encouraging players to play that way. That's not really the fantasy I'm going for with the class/subclass, because while I think it's cool, I also think it's way too specific, and like you said, easier to just role-play.

I guess the fantasy I'm trying to express as a class/subclass here is that of a storyteller, whose written stories give them literal power. I also like the idea of those stories being based on actual in game events they've experienced. I'm really just trying to figure out how to best express that mechanically.