I give an example, it will be long but I hope it could shed some light on something which is called variance (aka luck).

Let's play a game: I generate random numbers in the range 1..100 and on a 90 or higher you win, 89 or less give nothing. So on each roll your chance to win is 11% (11 lucky numbers out of 100). You can think of each roll as a day of farming in Diablo and each win could mean getting a legendary.

I went to random.org which is one of the undisputed sites to give true randomness (heck they even make a living on selling random number services). I asked the site the generate random numbers in the above manner for 100 times. Here are the numbers:

4,25,33,98,47,63,69,30,5,81

8,74,44,66,37,7,28,19,73,7

93,5,90,90,89,28,94,53,62,93

20,64,30,75,25,34,22,87,94,25

97,40,76,68,57,14,60,7,82,39

36,71,7,51,55,11,97,37,81,51

56,84,35,3,93,80,95,7,89,63

10,1,73,40,62,17,37,86,84,29

73,17,95,85,81,19,66,47,47,11

80,4,97,71,58,60,37,66,55,58

I marked your lucky numbers below with Y, unlucky with N, and summarized in each row the number of wins:

NNNYNNNNNN = 1

NNNNNNNNNN = 0

YNYYNNYNNY = 5

NNNNNNNNYN = 1

YNNNNNNNNN = 1

NNNNNNYNNN = 1

NNNNYNYNNN = 2

NNNNNNNNNN = 0

NNYNNNNNNN = 1

NNYNNNNNNN = 1

Let's look at this as a Diablo player:

I found a legendary on day 4, but after that I had to go for 16 days without finding ANYTHING! Man I was super upset, almost quit Diablo. But on the third week my luck turned, it was like raining legendaries, I found 5 in week, a legendary every second day! In the end you won 13 legendaries, slightly above the expected 11, so all-in-all I can consider myself lucky in this example.

Do you think random.org was "rigged" when generating the first and second row? Do you think random.org secretly "buffed" drop chances when generating the third row? Do you think random.org "nerfed" my drop rates after I got my lucky week?