Monte Cook, que criou as regras de D & D de 3ª edição nas quais o Pathfinder se baseia, acreditava que as habilidades de um personagem de alto nível frequentemente superam as dificuldades que enfrentam, de modo que os jogadores sintam que seus personagens são poderosos e uma sensação de um mundo consistente que existe fora dos personagens dos jogadores.
Let Them Kick Butt (Sometimes). When you play a computer game like Diablo, the program scales the game to increase in difficulty at exactly the same rate as your character increases in level. So, as an example (I didn't actually dig into the game to find the formula), if you have 10 hp at 1st level and inflict 1d6 damage on the monster with 5 hp, at 10th level you have 100 hp and inflict 10d6 damage on the monster with 50 hp. There are lots of interesting distractions, and Diablo can be a fun game, but fights at 10th level end up feeling exactly like fights at 1st level, and you still need to go back to town for healing potions just as often as you did before.
Don't let this happen in your D&D game. High level isn't like low level. At low level, everything is a challenge -- sometimes, a really tough challenge. While you should challenge your players sufficiently, make sure you also occasionally give them opponents they can overcome easily. The whole world doesn't rise in level as the PCs do, so when they have made it to 15th level, they should feel as though they really are superior to some of the foes they must face. If this isn't the case, then why keep trying to gain levels?
The whole point of these suggestions is to avoid punishing characters for being high level. If your players have reached 15th level with their PCs, it is because they played in your game for months and months. That's something you want to reward.
Fonte: Monte Cook, Design Secrets: High- Level Adventures , 2002.