Do you get less xp from a quest if you bypass all the addendums and side stuff?

[Kristobro]

For instance.. if I just run straight through the front door and kill Raedric without talking to the priest up stairs or dealing with the necromancer chick, does it effect the amount of xp I get from the quest at the end? Or is it more efficient to just bypass everything.

[Boeroer]

I don't remember every questline and the individual steps etc. - but usually you get some XP for intermediate steps of a quest and the biggest portion at the end of the quest.

So following those intermediate steps usually means more XP. If the questline has a lot of intermediate steps that all give a little bit of XP it can add up. Now it's up to you to decide whether that additonal XP is worth your time and attention - or not. Imo somtimes it's worth it and sometimes it's not*. Def. depends on what you like to do and what annoys you. Anyway: there's def. enough XP in the game to max out the levels before the endgame, even witout doing every addendum/side stuff. This is especially true if you also have the expansions installed (White March I and II): it's supereasy even with rushing through the game to max out rel. early.

 * Example: when dealing with Raedric you can side with Kolsc and get some xp for interacting with him, then do all the small XP-stuff you can do to reach Raedric (talk to the wizard in the basement, talk to the Priest, gain access to the secret door and whatnot), finally approach to Raedric and then flip: get some XP for siding with him then and agree to kill Kolsc. Then go and talk to Kolsc again, kill Kolsc (XP), return to Raedric, get XP for completing the Kolsc task but then kill him, too (again more XP)!
I think that is the max. XP you could milk out of the whole Raedric questline - but at the same time: is it worth all the effort and all the time you spend running around? And also: Doesn't it feel weird and not in line of you really thought your char would do (role-playing wise)? And then also: barreling through the castle directly and killing Raedric might net less XP overall, but you'll get a ****ton more valuable loot from all the enemies in the castle - and better equipment (or money from selling that equipment) can be as important/rewarding has getting more xp. 

So what's more efficient? Sadly "it depends"...  But I hope my point came across somehow. 

[Chaospread]

In the wiki there is the experience gained for each step of a quest.

For "Lord of a Barren Land" intermediate goals weigh more than the last target: https://pillarsofeternity.fandom.com/wiki/Lord_of_a_Barren_Land (see "Experience gained" in the right pane).

BUT, if you read here https://pillarsofeternity.fandom.com/wiki/Experience_and_advancement#Quest_experience:

On quest completion, the "end state" objective experience is granted, plus whatever experience remains from the total (typically consisting of the fractional remainders that accumulate if the total XP cannot be divided into whole numbers for each objective), meaning the end state will often grant a few more points of experience compared to objectives with a weight of 1. Ultimately, if there are objectives that have not been completed, the party will be granted experience equal to the value of these remaining objectives. As such, the amount of objectives completed does not influence the amount of experience granted throughout the quest.

So if you go straight to the end state you get the total xp even if you skip intermediate tasks.

[Boeroer]

Ha, I didn't know that.