My recent Serenity campaign tossed aside the concept of advancement altogether after a couple of sessions. Why did I do that? Well, largely it was because when I run a skill-based game rather than a level-based game, I find that advancement tends to run very strangely.

Then too, the characters are competent enough to do what they needed to do (well, as much as the system allowed them to), so actual advancement wasn’t so necessary. 

Instead, far more important to the game were rewards in terms of plot and personality, as well as “hard” rewards like a home base for their ship and trade cargo.

This is in distinct contrast to D&D, where I’m not particularly fond of freezing advancement. I’m a lot happier with advancement using level-based systems, as the characters tend not to “get weird” with their abilities. To add to this, the system gives a lot of interesting foes and powers as PCs go up in level – it seems a shame not to explore them!