In the same way that bards could find "perks" that modified a feat (bard song) to get diferent results, wich turned out to be incredibly fun, i thought fighters could get somthing similar, but with combat styles.
A fighter finds a scroll with a technique or a comabt style, and can, spending some XP, learn it and have it avilable to modify a combat feat just like a song would modify the bardsong. The tool used would be much like a songbook, except that it would be an OOC tool.
For example,
- Certian technique could modify Imp. Power attack to instead grant aditional attacks per round and loose AC.
- Or Imp. Expertise to give less AC, grant a bit of concentration and discipline and loose all other attacks per round
- Or dirty fighting to create short-lived cumulative random penalties on the target should it fail a "X" save.
- Or improving parry mode by giving aditinal damage but less AC while in it.
As well as:
- Make called shot be able to hit the liver, and create a CON penalty, or a fort save penalty.
- Make Improved disarm knock off the shield, rather than the weapon
- Make Whirwind attack instead confuse nerby enemies giving them a penalty
Stronger perks like Imp. Disarm or Knockdown should have less powerful alternatives, while alternaitves for say, whirlwind attack, should have powerfull effects. In the same way, the techniques for combat styles would require feats like Imp. Power attack, so that it takes an investment in feats players don't often do, and feats like dirty fighting should have better alternatives than things everyone uses, like Imp. Expertise.
This will also encourage people to take more fighter levels, even asuming it doesn't affect the feats, to get as many combat feats as posible for the various alternatives they may find on their quests.
This sounds like it would be complex to implement, but you're thinking in the right direction, DT. I support the thrust of the idea, if not the specific suggestion.