How does 2x drop actually work?

I apologize if this subject has been covered, I did use the search option at the top and looked but couldnt seem to find an answer for this. How does 2x drop actually work, for example, when being used on Zakum? I have heard 2 different theories:
1) The person with 2x drop HAS to do the most dmg to zakum, I am guessing this applies to the 3rd body, for the 2x drop to work properly.
2)The person with 2x drop has to apply the mortal blow to Zakum for it to work.

There has been much debate over this subject in my guild and I havent found an explanation on nexon's site covering it.

Thank you for any input you have

I believe both (1) and (2) have to be fulfilled for the 2x drop to work.

For Zakum, at least, it's both most damage and final hit on Zakum3. Unless it's been changed recently for some reason.

Ty so much, I wish nexon could give us a little PRODUCT DESCRIPTION of the items they offer in CS.

Ty so much, I wish nexon could give us a little PRODUCT DESCRIPTION of the items they offer in CS.

They do. *cough* (Transparent hat)

I have an additional question regarding 2x. Say I'm fighting Anego (A 30 minute solo for example), and only a couple of minutes before I know that I'll be killing her, I activate a 2x drop card. Does my Anego kill count as 2x drop?

I've done the exact same thing for 2x Exp, and yes, I get credit for a full 2x exp kill even if I've activated the 2x exp minutes or even seconds before killing the boss. I've just never been able to confirm that 2x drop actually works in the same way.

I'm pretty sure it still counts since, I have done this for pap and entered 10 minutes before 2x drop started so I would save some of that 2x drop time. Pap still drops more stuff then usual. I did it every day when I had a 2x drop coupon for 30 days.