Mustrum_Ridcully said:The quest cards are not the mechanic. They are a suggestion how to represent them a game, similar to a suggestion of giving the players a hand-out with the map of an area, minus the secret doors, traps and other DM secrets.
The Quests are basically "story-based" XP. So that a DM can grant XP for stuff that's not an encounter with other creatures, or where the XP value of the activity is badly measured with the XP value granted for overcoming the challenge of a monster/NPC. (Like dealing with an aristocrat that you could easily kill, but don't want to, because that's not the solution to your goals...)
I already do this in my 3.5 game. I give xp when they complete a "mission". Usually just bonus xp when they accomplish something.