Characters in Vivid 3.0 are defined in terms of their Traits, Assets, and Hooks.
Traits tell you what the character is and thus what the character can do. Traits are freeform – players get to choose or make up Traits for their characters. Players assign four Traits on a 4-3-2-1 ‘stepladder’ so everyone ends up specializing in something, and is weak at something.
I envision Traits to be shorthand dramatic role descriptions that can immediately tell the GM what the player is interested in doing and maybe how he wants the character to do it.
If for example I give my character a Trait: Debonair Lady’s Man, my GM should expect that I want to have a crack at roleplaying seduction attempts and/or romantic entanglements. If I give my character a Trait: Cunning Swordsman, my GM should expect that my character tries to win in close combat using tricks and quick thinking.
I’m also heavily influenced by S. John Ross’ Risus system, wherein players are encouraged to write up highly descriptive Traits. I just love this idea, and will go so far as to bribe players to do it: if by your Trait description you can do something even better than normal, and you do roleplay according to that Trait description, I'll give you an Advantage bonus die.