Sorry for being uneducated on BG3 and D&D - I haven't played the game yet!
Just trying to learn a bit by reading guides and tutorials, preparing for a future playthrough!

Right now I'm playing Kingdom Come Deliverance.
In that game you hardly create a character at all, but while playing you earn XP in loads of different skills, and when they level you sometimes get to buy a perk from that particular skill tree!
If I pickpocket a lot, I will earn XP and level up in pickpocketing, and get to buy cool perks for that.
If I talk to everyone I will level up in speech, and can choose perks for that.
If I play stealthy I will get loads of stealth-perks to choose from.
As well as all the perks from the main level - every second level I get a point to spent on those unspecific perks.
Very fun system, specializing from how you choose to play the game, and get loads of options!


I get the feeling BG3 is the exact opposite?!
You spend hours upon hours creating you character - choosing background, race, feats, class, subclass...
...but when you start playing, the only thing that really happens during your 100h playthrough is that you get to choose three feats/perks?
It's all about loot, combat strategy, party composition, and leveling up is almost no part of gameplay at all?
Except you gain HP etc, just like your enemies will...
Have I missed anything big, or is this sort of how it works? :)

To answer your questions: yes, you missed everything and no, that's not how it works.

Ok, great!
So what do you get to choose while leveling up, except those three feats?
I guess you unlock several new spells, but maybe nothing you choose specific but rather just unlock, but what else that you can tailor to your playstyle?

One thing you may be missing: BG3 will default a lot of your selections for you for many of the characters. If you're not paying close attention, you may miss class specialization or feat selections.

Also, there are a lot of things you *don't* get to select, but that you still gain, when leveling up. New abilities, additional uses of existing abilities, etc. If you're a caster, level-up is also a chance to learn new spells or change the ones you know.

The feats and such are powerful, but the automatic boons you get at various levels, depending on your class, probably make a bigger difference. Those will show up as a small icon on the level-up window, but you don't select anything.

As alcaray said - you can also multiclass. Any time you level up, you have the option of putting that level into a different class, and you can do this as many times as you want. One thing I like to do is level Astarian as a Bard. His first level is Rogue, so he gets the level 1 rogue abilities, but everything after that I put into Bard, giving him all the bard abilities. This can be dicey - a lot of really powerful abilities happen after level 9, and not many happen before level 3, and you only get 12 levels... so you end up sacrificing high-end specialization for some versatility, but it gives you a lot of flexibility in how you play your character. There's even an achievement for leveling 1 level into each class and finishing the game (you'd better have a pretty amazing party, because a level 1 everything is going to miss a lot of stuff...)

I think the key in BG3 (and really all DND-based games) is that the race/class that you select at the beginning has a pretty significant impact on the long-term trajectory of your character, vs something like KCD which doesn't have the concept of class and instead levels your character based on what you're already doing a lot of (which is great if you want to do one thing all the time, but can also be super frustrating having to grind up a new skill just to make it useful. Fortunately, KCD seems to cater toward people who like to grind.) If you found Withers, you can pay to re-make many of those decisions and re-spec your character during the game, but your options will always be driven by the class(s) you've selected. Unlike KCD, there's really no way to just grind a ton and max out a bunch of unrelated skills.