I'm planning to build a table of random special combat effects. Each group of 6 effects is more difficult to achieve than the previous group.
For now I came up with a simple system in which a 1d6 is rolled. Every time a 6 is rolled, I deduce 1 and sum up the result. I stop rolling when no 6 turns up. However, I need your help coming up with the correct formula to calculate the odds for any given number so I can correctly build the table.
Example 1:
1d6 = 5
End result = 5
Example 2:
1d6 = 6
1d6 = 3
End Result: (6 - 1) + 3 = 8
Example 3:
1d6 = 6
1d6 = 6
1d6 = 2
End Result: (6 - 1) + (6 - 1) + 2 = 12