Did you not read the thread? You will only get XP from causing damage yourself.(Or from quests, but quest XP is much less than combat XP) Companions will only give XP from the killing blow, not from the wounding blows, which are much more common.

I read perfectly well your post where you claim that we must build a killing machine before everything else and I've just proven with my own experiences how wrong it is.

you dont need to build a killing machine, you just won't level up as fast if you build a non-killing machine. The fastest way to level up is to kill every enemy yourself so you get the experience. Letting followers do the work means less experience for you = less leveling up. That's not a huge issuel because the game is very long and you level up super fast on normal anyway. In fact its probably better with a non-killing machine build on non-patched version level 50 tops, it will stretch out the leveling a bit longer.

I dug up some old posts and here's how the experience system in Arcanum works exactly.

Each creature is assigned their XP worth based on their level. E.g. a level 1 creature such as the Ailing Wolf is worth 160 XP. When you hit the creature you get XP proportional to how much damage you did. The Ailing Wolf has 10 HP, you hit it for 5, so that's 50% of its health = 50% of its total XP worth = 80 XP. You hit it for 1 HP = 10% health = 10% XP = 16 XP.

If it's not the player doing the hitting, then that XP is lost. However, the game offers another XP bonus upon killing the creature, which is 1/5 of its total XP worth, so 32 XP in the Ailing Wolf's case. This bonus is always given to the player.

To sum it up:
When you kill an Ailing Wolf yourself, you get 160 + 32 = 192 XP in total.
If you let Virgil (or another party member) do it, you only get 32 XP.

Not exactly.

If you're the only one to hit and kill the ailing wolf, you get the max of 192 xp.
If you hit the ailing wolf but virgil kill it, you can get up to 160 xp.
If you don't hit not kill the wolf, you get the 32 xp only.

yes everyone is just saying the same thing over and over. we get it lol. Like i said, followers steal experience only a main character who kills everything himself gets the full experience, so having a non-combat character who's not good with going through the game being the one and only superman (warriors, gunners, mages) penalizes you with followers.

Now again, thats a big deal in the beginning when your trying to level up, but later in the game isn't a huge deal since the game is very long, and offensive characters can get up to levels 40-50 very fast if they are the only ones doing the damage/kills, unpatched pretty boring 1/3rd of the way through the game when you have max stats, spells, items, and can easily kill most anything yourself, and even the hard foes just pop a haste potion or haste spell and THEN kill everything.

So yea i got bored being the solo warrior, then mage, being level 40 still in the first areas not even doing the wheel clans yet. So now going to try either a thief, or just a leader with tons of followers, getting less exp with the enemies, but maybe it might be more fun being level 20 at that point not killing stuff myself than level 40 and really pretty much almost done with my character before level 50

Actually, it's rather the exact opposite. Followers get 0 xp from combat and depend on the main character to level up so each time you do not kill a creature, you're the one stealing xp from your followers.

Not at all.
From Shrouded Hills to T'sen-Ang, there are only three fights in the main quest and a lot of non-combat sidequests.
It matters only at high level, when the main character needs much more xp to level and therefore needs to be able to kill things himself to get the full xp.
So when you choose to fast-level, not only you miss a lot of the game contents but you force yourself to build a combat based character early on... and that's your choice, nothing to do with something broken in the game design.

I do play a mage thief with CH 20, persuasion 5 (master). My team is : Z'an (useless but she's just too fun), Loghaire (tech tank with a lot of knowledge about the world, I love to explore with him), Dante (mage tank-support) and Vollinger (tech gunslinger).