General

Let say I kill lachelein dreamkeeper 320k exp choco power buff will give me 160k if it 50% and Mercedes and zero exp thing won't stack

@hualicious: Uhhh, I guess. I don't really understand it because I suck at math. What snowman said.

@deeemon: So according to your screenshot it should stack, right?

I see the following lines:
-Burning Field Bonus EXP 70% (+38822)
-You have gained experience (+55461) = a mob you killed
-You have received bonus EXP (+55461) = exp coupon (USE tab)
-Child of the Goddess Zero, Elven Blessing, Choco Power! Bonus EXP (+27731)
-Buff Bonus EXP (+55461) = 2x EXP from a Rune

Beside of the above lines:
-Equip Item Bonus EXP = Pendant of the Spirit and any other equipments that gives EXP
-Bonus EXP for PARTY

Choco buff is an additive 0-50%, capped at 50%, and shared with Zero Card/Mercedes Link.
If you have 10% from Mercedes link, Level 240-250 Choco buff is the same exp.

@deadangel13: There's a Combat tab thing, next to Say, Friends and Guild, dood.

@deeemon: wtf how did you manage to get all that exp info to your chat?

I don't think so? http://i.imgur.com/8bJtQ94.jpg

Yea I understand the buff stays all day but do you get the bonus exp from the 2x exp coupon?

I don't know if one overcomes the other (like drop buffs with big spider), but I've tried and they don't cancel each other's icons. the choco buff (which I have not spent any of my time reading about) just stays there all day long.