Larian Studios Forums Divinity: Original Sin 2 Divinity - Original Sin 2 - Help/Tips/Tricks Gaining different amounts of XP on party members

I noticed that 1 party member (not main) somehow gained 1500xp more than others on the Lady Vengeance sometime before the boarding battle at the end of Act 1.

Later, I noticed that on the Three Altars quest, my main gained 18400xp for interacting with the altar, but noone else gained any xp.

What gives? I thought everyone would gain equal XP as opposed to everyone having different XP amounts

my main character is currently a slight amount of exp ahead of the rest of my party. no idea how, when or where it happened

it seems pretty inconsequential but it's a little jarring when one person levels up a little before anyone else

There are some quests that only benefit the character that takes it.

The example is act 2 "the 3 altars" quest.