Pretty sure the GMs don't tell rates. They just say low, high. I've never heard them say ##%. Not sure why drop rates are so secretive though? If they're too low, people might no camp certain mvps? Highly doubt it. Would just make it easier for one or 2 people to camp something since others wouldn't think it worthy of camping. And if its too high, more competition? Is that really a bad thing? ._.
Good luck getting an answer though, I never got a response from my Tirfing sword drop rate topic. =/
