Maximize gained experience.

[TORYU]

Are Elder Knowledge trait and Sagestone ring the only way?

[rolandoftheeld]

And playing on Nightmare.

[Yunareiska]

I mean do you need more than that?, both those items is +50% exp and exp needed is capped at a set amount, I dunno even on normal I get somewhere around 5-10 points per adventure roll

[Elenvin]

I would also suggest playing Public or with friends having the Teamwork trait leveled.

[Phobos]

Nightmare is not optimal for xp, although you do get 30% more, the mobs will have 250% hp.
Even if you get through it without any trouble it will still take longer and outweigh the benefit imo.

[keller]

The optimal way to gain XP is to rush through the overworld and dungeons, only stopping to grab trait books that are in easy reach. Most of the sources of XP, scrap, and iron that you acquire in this game are not time efficient, while others; like loot chests, trait books, and bosses; are highly efficient. Let me explain what I mean. I haven’t tested this rigorously yet, but it seems to me that the vast majority of xp that you will acquire in this game comes from bosses and trait books, probably around 75%. And in the amount of time it will take you to clear out every nook and cranny of an overworld area, a dungeon, and then a boss, you could have gotten through two bosses if you had blown right through the overworld and dungeon, ignoring everything that isn’t the aforementioned trait books and loot chests and just killing the bosses as quickly as possible. So despite the fact that you’re getting 75% xp per boss run, you’re actually getting 150% xp per unit time.

It’s just taking advantage of how much faster it is to just grab a trait book that’s sitting in your way vs killing a whole area of enemies: they’re worth the same but one takes way longer. So just keep rushing bosses and rerolling your world to spawn new trait books when you’re done.