Pathfinder Adventurer's Guild
The Martial Magic Curve
In Pathfinder there are two major means of doing things magically or without magically. When we’re talking about classes the classes that rely on spells: Wizards, Sorcerers, Clerics, and Oracles, are all magic classes. While fighters, barbarians, rogues, gunslingers, and monks are all martial classes. The rest of the classes are a mix of the two, though most have a leaning one way or another.
In raw power the two are balanced fairly well. However in the number of options, the magic classes are quite a bit stronger. This is somewhat managed by limiting the number of spells a caster can use in a day, but this becomes less and less of a problem with casters while the variety of spells increases later in the game. This leads to a curve where in general the lower the level the better a martial class will do in adventure compared to a magic class and the higher the level the better a magic class will do.
Feat selection can change this quite a bit and multi-classing properly can do even more, however it is almost inevitable that a level 1 rogue can do better than a level 1 wizard in most situations, while a level 20 wizard will do better than a level 20 rogue. From levels 1-6 martial classes tend to be better. From 6-12 they even out and from 13 and beyond magic classes start to really break away.
Does this mean that you should avoid playing classes when they are not at their peak of effectiveness? Of course not, there is a whole lot more to roleplaying than simply rolling dice and being “the best,” and there is plenty of fun to be had in seeing through a character’s perspective regardless of their ability. This is just to explain something about the game that is not immediately obvious.