Running through a dungeon repeated times trying to get an epic item my wizard doesn’t have. I want 1 18 on the d20 to get it. It’s Frostsilver and I get 3d20 every time easily. But despite having rolled about 60 dice I haven’t rolled a single 18. (Yes I’ve gotten 19s and 20s.) Statistically I’m getting lots of repeats of numbers, and some not at all. I believe you don’t have a real 5% shot for any number and instead have different probabilities based on the quality of the reward.