I haven’t even really begun to consider the implications of this, but:
What if, as an alternate form of Level Advancement, instead of tracking experience points, you tracked encounters.
And instead of all encounters counting toward this total, you have to get a certain number of various types.
For example, to gain a level you must have 14 encounters, which must include 1 combat with 8 or more foes, 1 combat with 4-6 foes, 1 combat with 2-3 foes, 1 combat with a single foe, 2 social encounters, 2 roleplaying encounters, 1 trap, 1 puzzle, and 1 exploration or investigation.
Of the 4 combat encounters, 2 must be against foes with strong magic resistance, and one must be against a foe with strong weapon resistance.
No more than 1 encounter in each category can be APL -1 or lower in CR, and no more than 7 can be APL -1 or lower CR. Encounters with a CR of APL +3 or higher count as two.
These would be tacked on a simple encounter sheet, which would also name enc encounter (and have a line for notes, helping players and GM easily remember what has happened).If you have an encounter of a type you’ve already maxed out, you track it as a repetitive encounter. For every three repetitive encounters you have, you can mark off an encounter of a different type.
If the GM fails to make the appropriate encounters available 75% of the time, you get to throw pickles at him.
(I DID mention this is a first blush idea.)