This seems like a good a game setup as any to suggest this. Can't remember where I read/saw/heard this. So, going off memory here, but it was relevant to one of the warhammer games - maybe rogue trader? Can't remember which.
The suggestion has 2 components.
The first - every character has a kind of demeanour/personal goal. It's usually a positive statement of a sort that tells others how the character is likely to behave. Examples:
"I will protect those weaker than I."
"I will discover and preserve knowledge."
Doesn't have to be 'noble': "I will risk others for a profit."
"I will kill to make things easier for me."
At the end of a session - group discussion determines if a character has fulfilled their demeanour. Bonus XP for doing so. In Warhammer terms - between 35 and 50 XP was awarded, so that successive fulfilments eventually added up to an advance.
The second element is character links. This one determines some elements of the character interrelationships. In this case, they are also positive statements, but refer to another character specifically. It's generally expected for the 'target' of the character link to also help with the RP of the link. The link is not mutual - Character A can have a link to B, and B can have a separate link to A. Fulfilling a link only rewards the 'source', not the 'target'.
Examples:
"I know X's secret, and I will help him/her preserve it."
"X is soft, but I will make him/her hard like me."
"X owes me his/her life and doesn't know it."
"I think X is a liability, not an asset."
Characters have 2-3 connections at a time. After fulfilling one, they get a new one, usually based on events of the game.
There's clearly a lot of room, and warhammer is pretty well suited, in terms of both the setting, the RP and the reward system (a third of a half of an advance for fulfilling) to have this going. I'd like to try, especially since it transfers a lot of the creative process to the players, giving Chimera plot and situation hooks, so he can focus on making Shadowrun stuff
