Try to be on minimum Paragon Level 400 before you plan to enter Level 70 Great Rift. Greater Rift requires Rift Key to enter, they are dropped by Guardians in the regular rifts. When primals were first introduced people conducted tests with thousands of items and they got results between 0.22% and 0.25% for primals, i.e. How do you get ancient primal gear in Diablo 3 To unlock Primal Ancient items you will have to complete Level 70 Great Rift. However, your assertion that 10% of ancients are primals would mean that the chance of primals would be 1 in 100, or 1%. Now, whilst Blizzard have actually stated that the chance of a legendary being an ancient is 1 in 10, they have never actually stated the chance of a primal.

According to the law, the average of the results obtained from a large number of trials should be close to the expected value, and will tend to become closer to the expected value as more trials are performed. In probability theory, the law of large numbers (LLN) is a theorem that describes the result of performing the same experiment a large number of times. Well, statistically speaking, the figures I used were known as Expected Values, which is a specific term from the Law of Large Numbers. And dont say 40 in 400 are ancient … learn what chance is … statistically speaking, there is 10% for ancient and 10% from that for primal

Diablo 3 primal ancient