What effect on the advancement math comes from re-tooling the experience system in 4e?

Question

D&D 4e loves its experience pools in encounter building, and, because it is a system that inherently cares about party balance, carefully has laid out the math for experience - to encounter level -to advancement ratios. But my game group has done something entirely different.

My GM has simplified the experience system to this: Every 10 xp a character levels up. XP is awarded based on relative strength of the encounter to strength of the character. Example: Player A's lvl 14 ranger, B's lvl 8 cleric, C's lvl 10 battlemind and D's lvl 12 mage all get into a EL 12 fight and succeed. A would be lucky to receive 1 xp point. D would probably get 1. C would most likely get 2, and B would receive 3 points.

(While not pertinent, he also rewards bonus xp points for completing missions and good role playing.)

I'm thinking of adapting this system to a 4e campaign that I am going to run, but am wondering how this type of radical shift in the advancement system will affect encounter-building, or if I should be worried that my players won't advance fast enough, or more likely will advance too quickly.

Answer 1

The advancement system you use is irrelevant, and in fact you can do away with any formal advancement system at all and just level up when you feel the time is right. There are a few other important things though that should be regarded when you are doing this.

4e's baseline math assumption is that you're going to spend about 10 encounters on a given level. This does have implications for advancement, but, really, it only has those implications for the purposes of making sure adventurers acquire sufficient treasure. Instead of this you have several options. The easiest is to have characters discard their equipment each level up and redo all their gear with level appropriate stuff (L+1/L/L-1 uncommon or common items, and enough gold to spend on a L-1 magic item for commons). However, some groups find this less fun. Instead you just need to make sure that you distribute 10 parcels of treasure to the group per level (using the parcels from the DMG or rolling parcels from the RC).

That's basically the only consideration on pace of advancement.

However there is something else concerning about what you're trying to do. 4e does not work well with multi-level parties. You may be able to successfully run the system with characters within one level of each other, but because the math increases every other level, it's inadvisable to play with multiple levels in a party.