Dave Turner said:I see this question arise every month or so around here and it points to a deep problem in D&D. The game is ostensibly designed for 20 levels, but people invariably stop short of that level when playing. There is something deeply wrong with the rules of the game when people stop playing short of the implied end of the power curve.
I'm not sure if this is an indicator of a "deep problem" with the system. I instead attribute it to two factors: 1st/2nd Ed inertia, and accelerated level gain.
If you're a grognard, go back over your AD&D material. A couple things will likely jump out at you: "name" level (that level at which a PC begins experiencing diminishing returns for advancement in the form of fewer hp) and the relatively low assumed level of the "superheroes" of the settings (example, GDQ, in which the PCs of level 8-12 up to 10-14 fight giants, dragons, ancient races, demons, and a demon goddess on her home turf - this is epic adventure!). And while a handful of adventures were released with higher levels in mind (Isle of the Ape, anyone?), most of the top tier adventures ran somewhere between 10th and 14th. This speaks of an accepted power curve that did not reach the top end of the spell spectrum.
Now don't get me wrong: there were some abberations. FR was responsible for many of them, in the form of overly high level NPCs, but they also cropped up in Dark Sun, in Spelljammer, in Planescape (though I'd argue that if anyplace needed those abberations, it was the last). But by and large you saw a power curve that ended with name level, or soon afterward (like 13th, the level which fighters got hit with their # of attacks cap).
Fast forward to 3E: levels past "name" now provide very tangible benefits all the way up to 20. The experience point system encourages quick advancement. And Prestige Classes, whicb provide new and exciting abilities, provide even more incentive to continue quick advancement at higher levels. Suddenly the power curve ramps up, as the top tier becomes more attractive and more accessible. Is it any wonder that more campaigns chart to level 20 and beyond?
Truthfully, I think that if you wanted to "fix" a problem like this, you'd be best served by reducing the advancement rate. While the incentive to progress would still exist, making it take longer would allow campaigns to wrap up at lower levels and serve as a (more effective) cap.