Tuesday, February 7, 2012

Traveller Elegance of the 2d6 system

The 2d6 system for TRAVELLER seems to be a very simple system, and you would be right, it is. The beauty of it is, that a skill of 1 can make a huge difference on the roll, for example, it makes a normal difficulty action go from 8+ to 7+, which of course is the average roll for 2d6.


Possible Combinations on 2d6
2  1+1  1 in 36 or 2.78%
3  1+2,2+1   2 in 36 or 5.56%
4  1+3, 2+2, 3+1  3 in 36 or 8.33%
5 1+4, 2+3, 3+2, 4+1  4 in 36 or  11.11 %
6  1+5, 2+4, 3+3,4+2,5+1  5 in 36 or 13.89%
7  1+6,2+5,3+4,4+3,5+2,6+1  6 in 36 or 16.67%
8  2+6,3+5,4+4,5+3,6+2  5 in 36 or  13.89%
9  3+6,4+5,5+4,6+3  4 in 36 or 11.11%
10 4+6,5+5,6+4  3 in 36 or 8.33%
11 5+6,6+5  2 in 36 or 5.56%
12 6+6  1 in 36 or 2.78%

So a character with a 0 skill, and 0 stat modifier will succeed a standard difficulty of 8, 15 out of 36 times, or 41% of the time. Bring that character up to +1 modifier in either Skill or Stat and that becomes 21 of 36 successes; or 58.33%. The same character with a skill of 2 and a stat of +1 brings the chance to 30 of 36 chance or 83.33% chance. This system requires very little math, making it very simple, a game that can be learned in one sitting. The system scales well with more difficult or routine tasks. Say, a simple task requires a roll of 4+, most characters will succeed at this roll most of the time as there's only a 16.67% chance of failure (6 in 36), a skilled character will typically only fail under adverse conditions.

Every roll in  TRAVELLER  uses the same mechanics.
a 2d6 roll using positive and negative modifiers against a target number.

Very Simple, Very Elegant; a tried and true method for a role-playing game.

Check out Traveller by buying Book 0: Introduction to Traveller PDF from DrivethruRPG.com only $2.97 at time of posting. This is a 32 page rulebook, that contains the core rules.