Random item spawns/loot

[scatter00x]

I'm only just getting into DFNs and I'm trying to understand how the loot settings work. It is clear how to give an NPC a given item as loot, or to pull an item off a table, but is there any way to influence the odds of those drops? I know on old sphere servers the command was something like item={000a 1 000b 3 000c 7 0 0 15} or something to that effect... so out of 15 tries, it would make 000a 1 time, 000b 3 times, and 000c 7 times (and nothing the remaining 4 times.) Is there any way to script like this in the DFN files? Or does it require a JS?

Also, if I set a chest-spawn out, can I make it spawn random items or random ammounts of items? I got the spawner working, but I don't want it to create the same item every time. Preferably I'd like it to spawn off a random probability like I mentioned above.

Your comments are much appreciated.