I started out farming dragon seriously like a couple of days ago and I've done around 70-80 runs in total including something that I've done before.
I was just wondering that what is the exact drop rate. I've heard somewhere that it's like 1/1000 without any stuff. So what's the effects on the drop rate with Big luck. And how would a 1.5x combo elixir and 3x elixir effect on the drop rate as well, how much smaller will it be?

Thanks for answering.