How would you handle true polymorph?

[Spacehamster]

You loose all class levels when you perma morph so my question is: since most that true poly turn into intelligent beings would you let them start earning class levels as that creature(from 1-20)? For example a dragon wizard or a fighter or paladin Angel perhaps? Would ofc not gain levels as quickly since you are very high level when you morph but level 1-10 could cost the same as going from 9-10 for example?

[Ninja_Prawn]

would you let them start earning class levels as that creature(from 1-20)?

I see no reason why not. If you're letting a PC play as a CR 20 monster, you might as well let them get class levels too.

I might draw on the epic boon rules for levelling - was it 50,000 XP per boon? Seems a lot for a class level, but if getting class levels was easy, every dragon would do it. Or you could multiply the normal thresholds by something, maybe 10 or 100.

[Sigreid]

I agree with Ninja.

[Logosloki]

Epic boon per level sounds like it would be about right for an eyeball xp (it's 30k xp I think). If the campaign was continuing on I might even throw in the first level for free. If anything though you might find that a level per epic boon might actually be a bit too long, even if they are one of the finest murder machines invented.

[Sigreid]

Epic boon per level sounds like it would be about right for an eyeball xp (it's 30k xp I think). If the campaign was continuing on I might even throw in the first level for free. If anything though you might find that a level per epic boon might actually be a bit too long, even if they are one of the finest murder machines invented.
I don't think it's unfair to make them earn first level. After all, they have to learn how to cast with a new body and think with a new brain.