Well I've seen a lot of players especially newbies that are worried because of the random loot acquisition in dungeons. It's quiet a bummer especially for such rare drops (Divine Tree Ring, Boss Pet Scrolls, Etc.). So in case you're the type of person asking help from your buddies to ease your hunting difficulties and would like to guarantee your much coveted not to be accidentally obtained by your buddies helping you, follow these steps:
1. Make a room (preferably a private one).
2. Ask your buddies to enter the room.
3. Before starting the game, let your buddies fill up their inventory (e.g. Inventory slot 490/490) and make sure you have a lot of free inventory space.
4. Loot all you wish in the dungeon (since your buddies can't receive more items, all loots will automatically end up to you.
Happy Hunting