The PCs in my Classic Traveller campaign have all gained two skill levels over the course of several year of play, and are all currently “studying” for two more.

Originally I simply accelerated the process in the Classic Traveller books for character improvement, but after a few years of real time play, without years and years passing in-game, I simply told them to make those skills they were studying permanent and to add two more to the “studying” list.

We start every game from the exact in-game date we left off, and as of right now 412 game days have passed - just a little over one imperial year.

I need to rewrite the improvement guidelines on my campaign blog.

Really, the players don’t seem to care that much. The game has been a lot of fun and they don’t seem so focused on advancement as you find in games where you level up or whatever. One thing I love about Traveller is that it isn’t a power fantasy in that way. Still, I think it’s good for the PCs to gain some skills over time. It’s not like they’re going to become super human or it’s going to break the game.