Bell Curves
2d6: How Often A Number Occurs
Test 
Occurs 
Chances 
Percent 
2 
1 
1 
2.78% 
3 
2 
3 
8.33% 
4 
3 
6 
16.67% 
5 
4 
10 
27.78% 
6 
5 
15 
41.67% 
7 
6 
21 
58.33% 
8 
5 
26 
72.22% 
9 
4 
30 
83.33% 
10 
3 
33 
91.67% 
11 
2 
35 
97.22% 
12 
1 
36 
100.00% 
Like the 1d6: Roll Succeeds page,
this page shows the chances of rolling a certain total or less.
If you are trying to roll an 8 or less (8) on 2d6, there are seven
possible totals that would succeed: 2, 3, 4, 5, 6, 7, 8. A total of 9,
10, 11, or 12 would fail the test.
Each of the successful totals occurs differing numbers of times in the table.
Frex, 2 occurs once, 3 occurs twice, etc.
In order to determine the chance of rolling a total of 8,
we add up all the "chances" for each number that would be a success.
In our example,
this would be the total number of times each total from 2 to 8 occurs:
1+2+3+4+5+6+5,
for a total of 26 possible rolls that would be a success
in the 36 total possible rolls,
26/36 or a 72% chance for any rolled total to be a success.
Copyright © 1999 Bob Simpson. All Rights Reserved. Last updated: 2001 Nov 29
