Percentile Rolls

The original Last Unicorn Games' rules for the Star Trek RPG used 2d6 as a basis for all rolls, which makes it a bit harder to provide direct modifiers in a sense I can easily understand. Therefore, the following tables help to translate these rolls into percentile amounts.

2d6 as Percentiles

Result	% chance to roll	= % chance
2	3	3
3	6	9
4	8	17
5	11	28
6	14	42
7	16	58
8	14	72
9	11	83
10	8	91
11	6	97
12	3	100

3d6 as Percentiles

Result	% chance to roll	Rough equiv.	= % chance
3	0.46	1	0.46
4	1.39	1	1.85
5	2.78	3	4.63
6	2.78	5	9.26
7	4.63	7	16.2
8	6.94	10	25.93
9	11.57	12	37.5
10	12.5	13	50
11	12.5	13	62.5
12	11.57	12	74.07
13	9.73	10	83.8
14	6.94	7	90.74
15	4.63	5	95.37
16	2.78	3	98.15
17	1.39	1	99.54
18	0.46	1	100

Note: The total sum of the Rough column comes to 104, indicating rolls of 3-4 and 17-18 to be so insignificant as to be each valued at less than 1/2 of a percent.