I've been bouncing around ideas in my head for an old-school-esque sandboxy kind of game. Reading about how older versions of D&D used treasure as the primary source of XP gave me an idea:
Mark where the treasures while building the sandbox- at least one per (non-random) combat encounter, but probably more in odd places, hidden by minor traps, etc. When the party finds one, roll for treasure per the Essentials rules (or pick one of the DMG1 treasure parcels), and check off how many they've found so far. When the party finds all ten, they level.
This gives you some interesting pacing opportunities- if you put ten treasure points in a dungeon, you know that the party could gain a level there if they clean the whole place out. Unfortunately, you lose the option to have quest XP, but you can probably work it out by having quests be rewarded with money.
The Essentials random rolls give you more granularity, since you can break up the ten treasures into forty separate rolls. You could even improvise in a treasure roll or two on the fly- you mention a tapestry on the wall and players ask if it's worth anything? Make an art object roll! The bard tells an awesome story in the bar of the dragon they slew? Make a gold roll or two to see if he gets any tips!
Mark where the treasures while building the sandbox- at least one per (non-random) combat encounter, but probably more in odd places, hidden by minor traps, etc. When the party finds one, roll for treasure per the Essentials rules (or pick one of the DMG1 treasure parcels), and check off how many they've found so far. When the party finds all ten, they level.
This gives you some interesting pacing opportunities- if you put ten treasure points in a dungeon, you know that the party could gain a level there if they clean the whole place out. Unfortunately, you lose the option to have quest XP, but you can probably work it out by having quests be rewarded with money.
The Essentials random rolls give you more granularity, since you can break up the ten treasures into forty separate rolls. You could even improvise in a treasure roll or two on the fly- you mention a tapestry on the wall and players ask if it's worth anything? Make an art object roll! The bard tells an awesome story in the bar of the dragon they slew? Make a gold roll or two to see if he gets any tips!