What Makes a Man a Fighter?
Fighters present a unique problem: since they embody a skill that is fundamental to all classes (combat), any modifications/additions to that core ability tend to generate an arms race among the other classes. There is nothing that the Fighter can do that doesn't make a kind of sense for some other classes as well, at least in combat. Usually people try to diffentiate Fighters by means of higher bonuses, but this often contributes to bonus inflation in D&D combat in general. My solution to this problem in S&W is to allow Fighters to use Combat Maneuvers as move actions, thus increasing their versatility. So a Fighter can kick a chair in somebody's way and then turn and take a swing at another character without stopping. They can bull rush a guy off a cliff and then attack his buddy coming up on the flank. Fighters should be the 'mosh pit masters' of S&W, always able to do a little more in combat than everybody else.
Otherwise, they function as follows:
Hit Die: d10
Attack Bonus: +1 per level
Saving Throw: As in Core Rules.
And that's it. I often want some other kind of skill to make Fighters different, but I suspect I'm just overthinking it.