Need help from any forum members who know, how the drop loot system work.

How the system decide about what player get what item? Is it the one that gives most damage? Or the one who make the killing blow?

I helped some new low level members finishing quests. They are around lv 13-15. Finishing the windmoore harbor - grog beach, and the dessert - arcanum castle.

They literally do nothing but escaping and potion spam in bosses. But then when the battle is done. They always get the good stuffs such from golden chest, locked crate, and legendary item.

One time when I hunted elite maps, One of the player literally stuck and can do nothing, then he got killed and return to battle. And when the boss is killed, he is the one who got the malison egg. Even when he is not participating much in the battle. Me and the other player are just looking each other and like... "what the..." LOL

Can someone help and give explanation on how the system work? Thanks in advance