Oh, this is a very nice mechanic -- and I don't even play Star WarsIt's a personality mechanic. It's not yet playtested and not yet fully thought through, but it will work like this... There are six dimensions:
Courageous / Fearful
Humble / Proud
Responsible / Reckless
Trusting / Suspicious
Generous / Selfish
Forgiving / Vengeful
They are rated from 2 to 12. The players may distribute 45 personality points on these dimension. In dilemmas or emotional situations, the GM may ask the player to roll 2D; if the roll is the same or below the personality stat, the positive pole dominates, and vice versa. In case of a rolled 2 or 12, the personality score shifts 1 point toward the dominating pole.
I introduced this system because in an all-Jedi group the Dark Side plays such an important part. Falling to the Dark Side just needs some mechanical representation that gives the GM and players a common ground.
Additionally, it makes it possible to tempt others to the Dark Side: By making a Persuasion / Intimidation roll against the target's Willpower, a Sith can force a personality roll. That means --depending on their personalities-- tempted characters are possibly forced to act against the Jedi Code, thus slowly turning to the Dark Side.
Example: Darth Nefari fights a Jedi. The Sith Lord knows from previous interactions that even though this particular Jedi is not particularly vengeful, he is very proud. Thus, when trying to seduce him to the Dark Side, she decides to aim for his pride: She insults him and the Jedi Order. (Persuasion vs. Willpower) If she succeeds, the Jedi must roll on his Humble/Pride-Stat. If he fails, his pride is hurt and he gets angry. (GM decision: A malus on any other personality checks during this exchange.) As a consequence, for the rest of the exchange the Jedi more vengeful than usual. Should Darth Nefari now also succeed in provoking him to attack, he'd gain a Dark Side point... making his first step towards the darkness.
Force-users also have:
Balance / Dark Side
These are normal Dark Side points, with two exception:
1) They go up to 12 now, 2) They can act as a personality mechanic / replace them.
The more Dark Side points a character gets, the more the Dark Side controls the character. In any given moment, the GM may ask the player to roll the Dark Side stat instead of the appropriate personality stat.