How digital dice rolling works
Each roll uses a cryptographically seeded random number generator to produce a value between 1 and the number of faces on the die. The result is uniformly distributed, meaning every face has an equal probability of appearing — just like a fair physical die.
When rolling multiple dice, the calculator shows each individual result alongside the total sum. The theoretical average for a single die is (faces + 1) / 2. For a d6, that is 3.5; for a d20, it is 10.5.
Theoretical average = (Number of faces + 1) / 2
For a d6: (6 + 1) / 2 = 3.5. For a d20: (20 + 1) / 2 = 10.5.