The house rule that we most often add to a game is fan mail. It comes originally from Primetime Adventures, but the basic idea can be added on to most games.
Fan mail is basically hero points, but anyone can hand them out, for any reason. Any time a player does something that you think is cool or funny or awesome or clever, give them a fan mail.
In PTA, fan mail improves rolls and gives access to scenes. If the game you’re adding it to already has some sort of hero points mechanic, just use those rules for what you can use it for, and the only change is how you acquire them. You’ll have to judge whether the fan-mail hero points should be in addition to however the game normally has you earn them, or instead of.
If your game doesn’t already have hero points of some sort, the easiest ways to integrate fan mail are probably:
- give a fixed bonus on a die roll
- allow a reroll
- let you roll the dice twice and take the better result
But, really, the sky’s the limit. You could introduce scene setting or world editing with fan mail. You could allow fan mail to create or trigger opponents’ weaknesses. You could let it replenish resources (stress, hit points, etc.), or automatically succeed on rolls.
What you do with fan mail is kind of a separate issue, however. The important part is that everyone gets to give it out to everyone, and it’s an infinite pool that you’re giving from.
N.B.: It’s not an infinite pool in PTA, but when we’ve added it to other games, it always has been. If you have a problem with that, there are two easy solutions:
Give everyone a finite amount at the start of each session or storyline. You could do this individually, but following on the group nature of this I would instead recommend a collective pool to pull from.
Follow PTA, and have something during play build up the fan mail pool. This could be tied to player actions (every time you take damage; every time a roll fails; every time you take the SG’s story hook), Storyguide actions (for every 10 points spent on the opposition; every time an NPC rolls a critical success; whenever the Storyguide rerolls something), or the structure of the game (every scene; every 3 rounds in combat; whenever there’s a downtime scene; every 10th skill test).
If you haven’t give fan mail a try! However you implement it, I think you’ll find that rewarding players for being awesome and contributory—and particularly letting the other players do it—only makes your games better.