I logged onto PTR, did a T6 Rift, got a Greater Rift Keystone, went up to level 28.
I then did a T1 Rift, did not get a Greater Rift Keystone.
I'll be collecting my own data, but, does anyone have any official source or additional testimonial on their drop system? My guess would be similar to the Ubers keys (50% on T6)
Did 12 rifts (couple of Expert, couple of Master, the rest T1) before I got my first greater rift key. So if people are getting keys every rift at the highest Torment levels, I'd say it scales up pretty quick.
I then did a T1 Rift, did not get a Greater Rift Keystone.
I'll be collecting my own data, but, does anyone have any official source or additional testimonial on their drop system? My guess would be similar to the Ubers keys (50% on T6)
Personal Data:
T1 Rifts:
1 Run, 0 Keys
T6 Rifts:
3 Runs, 3 Keys
Greater Rifts:
3 Runs, 27, 28, and 29
Small sample size, so i don't know, maybe just bad luck.