Relationship Sandbox: Reputation & Favor Social Mechanics

Yesterday my Sunday night Masters of Mu campaign was heading into a session involving a big party with all 18 lords and ladies of the campaign base area in attendance.  Since this was a vital opportunity for the PCs to sneak into the party, learn some secrets and further their own political goals, I wanted a more complex mini-game involving plying the lords and ladies for favor, spreading rumors, blackmail, seduction.  Also, the game has no meta-plot in place, so I wanted to present an open sandbox of diplomatic intrigue for the characters to explore however they wished. I'll present the mechanics as I used them here, but there are some refinements I would probably make.

The system is based on two scores, represented as a bipolar (positive or negative) modifier:
Reputation is a measure of your general good or bad reputation within a specific area or social circle. So, you could potentially have different reputation scores for different places.  For my game's purpose, it was just one score relating to the campaign base area (The Isle of Hardstone) as a whole.
Favor is a sort of localized reputation applying to only one individual, therefore it's tracked separately per individual.

Both Favor and Reputation are applied as stacking modifiers to Charisma checks (roll stat or under on d20) when attempting certain actions.  These actions are attempted once per turn (10 minutes) while at the party, and must target a specific lord or lady.  All 18 of the lords and ladies were statted out ahead of time.  Each was given a few personality notes, as well as a special interest/hobby and also three secrets.

Since Charisma checks you want to roll low, negative modifiers are good, positive modifiers are bad.

The Party (turns)

• turns 1-2, greetings and announcements
• turns 3-4, dinner
• turn 5-6, dancing
• turn 7, jester entertainment
• turn 8, open entertainment
• turn 9, the Count makes a toast
• turns 10+, drinking and frivolity

I gave bonuses to certain actions during different phases of the party (seduction gets easier at the end of the night, etc.)

Actions

Each action can be attempted on one lord or lady by each player once per turn.  Some actions are easier than others, so additional stacking modifiers to the Charisma check are included.  Also, actions can be attempted on another character's behalf (for example, four players all trying to increase the reputation of a single player's character.)

• Flatter/woo (-2), effect: increase Favor
• Learn interest/hobby (+0), effect: increase Favor, and learn secret interest/hobby
• Spread rumors (+0), effect: must attempt to increase or decrease a specific person's Reputation score.  For every four successes, the Reputation is increased or decreased appropriately.
• Learn secret information (+2), effect: increase Favor, and discover one of the NPC's three secrets
• Extort/blackmail (+0), effect: get what you want from the NPC, but you must have some sort of secret information to blackmail them with
• Seduce (+4), effect: increase Favor and take the character to bed.  also learn some free secret information.

Critical success (natural 1) doubles the effect of the success.  Critical failure (natural 20) gives you permanent enmity towards that NPC and no other actions are possible.

A few examples from last night's game:

• The party's thief had been given a mission by the local thieve's guild to kidnap a high ranking NPC to hold for ransom.  She immediately targeted one of the Viscounts and throughout the course of multiple rounds, used Flatter/woo to increase her Favor score with him.  Once the dance started, she went for her seduction attempt and succeeded.  Once getting him alone, he was kidnapped and taken prisoner.  
• Three of the characters decided to pretend they were the royal retinue of a foreign, exotic lord (another one of the PCs, who definitely wasn't a lord.)  They all ganged up and spent the game spreading rumors about his wealth and physical assets to great success.  He'll be well known throughout the courts of the island after this night.
• The party's fighter has been accompanying the group to raid the local caves of monsters.  He spent the evening buttering up the Count and his knights, and at the end of the night made a proposition that he should be granted a well funded expedition into the caves -- and found success.

Further thoughts:

• The system could be adapted to use the standard 2d6 reaction roll instead of a Charisma check easily enough.
• There was a natural length and time constraint to this whole scenario due to the party timeline.  In campaign mode, I'd only allow a check for reputation and favor inside these mini-scenarios or once per big event or encounter.
• In a more complex system, the defending party might get some sort of saving throw or wisdom check, but I didn't care about that for this scenario.
• I'd love to experiment with some sort of playing board/matrix setup with counters in play to visualize the whole relationship web and maneuvering at the table.