This is an idea I've been developing for playing with the things that maintain some type of hold over a character's actions through the course of play.
I call them...
Virtue/Vice/Time Commitment Thresholds
The concept is pretty simple, it requires the game to be divided into scenes of indeterminate length that are relevant to the unfolding fiction. A number of these scenes being added together to create a session of play (typically a session of play will reveal a complete and distinct storyline). It uses traditional six-sided dice.
For every Virtue, Vice or Time Commitment possessed by the character, a single die is rolled at the beginning of the session. The number on this die represents the tension threshold of this character aspect; the higher the threshold, the more likely that the event will play a part in an upcoming scene.
All Virtues/Vices and Time commitments have a rating of 7, 5 or 3. If the tension threshold is equal to or greater than the rating, then this trait comes into play.
Thresholds (7 Negligible/5 Minor/3 Major).
At the beginning of every scene, roll a die for each of the relevant aspects. If the die roll is equal to or greater than the current tension threshold, increase the threshold by 1 then compare the value to the aspect’s rating. If the die rating is lower, then no change occurs.
Players may deliberately reduce the tension threshold by choosing to engage in a scene relating to their aspect. Only one aspect at a time may be addressed in this manner. Simply engaging this character aspect automatically drops the tension threshold by a point, but during a scene in which the aspect is addressed, successes gained by the character may be spent to further reduce the relevant tension threshold by 1 point each.
If a tension threshold reaches the character’s aspect rating, then a confronting scene automatically comes into play. The tension threshold does not automatically drop in such a situation, but a character may still spend any successes to reduce it.
If a virtue is brought into play through this mechanism, then the character will be forced into some type of situation where they have to make a moral decision regarding their virtue. A virtue of "truth" might invoke a scene where the character would gain some kind of an advantage if they lied, or they might be asked to reveal a secret that could damage them. If they uphold their virtue, they gain some kind of long term spiritual reward (perhaps experience points or a replenishment to their willpower...this all depends on the game where this mechanism is introduced). If they fail to uphold their virtue they gain a temporary but immediate benefit (+1 to a die roll, or something similar).
If a vice is brought into play through this mechanism, then the character will be forced into a situation where they are forced to do something wrong in exchange for immediate gain. A vice of "shoplifting" might invoke a scene where the character sees something that could prove useful to their current agenda. If they succumb to their vice, they gain the immediate benefit, while abstaining would give a chance to buy off the vice or provide some other long term benefit.
If a time commitment is brought into play, then the character must give up their current course of action and do something relating to the time commitment. Perhaps they have to pray at certain times of day, or maybe the have a day job or lectures that they have to attend. If they fulfil the time commitment then everything continues in the next scene as normal with some kind of minor reward (they get paid, their faith is restored), but if they fail to meet the time commitment there might be later repercussions that need to be faced.
If a character has more than one virtue, vice or time commitment, it is quite possible that two or more factors may come into play at one time. In situations such as these, characters may distribute their successes between each of the complications that have arisen in the current scene.
It's just one of many ideas I've had for integrating characters more carefully into the worlds in which they live.