Thornwatch - Hero Die and Trait cards. Art by Mike Krahulik.
Thornwatch copyright Penny Arcade and Lone Shark Games
The Thornwatch rules use Hero Dice to encourage roleplaying and let the players earn more powerful rolls. Hero Dice have an 80% chance of success, rather than the normal 60%, and a 20% chance of double-sucess rather than the normal 10%. Additionally Hero Dice never grant the Judge any Ebb when 0s are rolled.
Here is a variant that lets the players control Hero Dice rather than the Judge. Replace the first paragraph under "Trait Cards and the Hero Die" with the following:
Trait cards describe certain aspects of your personality that emerge during the brief time you spend in the mortal world. During the game, you can describe your manifestation doing something that exemplifies the trait on your trait card. If another player agrees, you can flip that trait card over to its other side, which displays a hero die. The description doesn’t need to be elaborate; you can talk in a different voice or give a rousing speech, but you don’t have to.
Players are still limited to earning one Hero Die per turn.
Player-driven Hero Dice encourage players to pay attention to each other's actions and descriptions, and give players a way to reward and encourage each other. It also means one less thing for the Judge to worry about during the game. With the print-and-play, you can even print out a number of Hero Die cards and give some to each player. Players can then hand Hero Die cards to each other immediately as a direct reward for doing something cool.
(In my tabletop RPG group, we used a house rule called "Pocket Points", inspired by these articles. Each game session every player received five Pocket Points they could grant to other players for good descriptions, acting in character, or great roleplaying. Pocket Points were worth XP (a scaling amount based on character level). Other variants use Pocket Points as a bonus on die rolls. It's a really cool feeling to do something thematic in-game and have other players around the table toss you poker chips or cards because they liked it )
You could also play with either the Judge or other players able to grant Hero Dice for thematic actions in-game.