I figured I'd share some of the homebrew changes I've implemented to Combat Expertise. I've basically replaced the original Fighting Defensively rules with the original Combat Expertise rules, and made Combat Expertise more about being an expert of combat maneuvers. This change was designed to help make Combat Expertise less of a feat tax for combat maneuver feats and also helps to compensate for CMB/CMD values at higher levels.
The version of the feat below is not my actual homebrew version, but is instead tweaked for the public currently using the standard Pathfinder rules.
Combat Expertise (Combat)
You excel at performing tactical combat maneuvers as well as defending against them.
Prerequisite: Int 13.
Benefit: You gain a +1 bonus to your CMB and a +1 dodge bonus to your CMD. This bonus also applies to your Bluff checks to feint in combat, as well as the Bluff DC to feint you in combat. When your base attack bonus reaches +4, and every +4 thereafter, these bonuses increase by +1.
Fighting Defensively:[b] You can choose to fight defensively when attacking. If you do so, you take a –1 penalty on all attacks in a round to gain a +1 dodge bonus to AC until the start of your next turn. When your base attack bonus reaches +4, and every +4 thereafter, the penalty increases by –1 and the dodge bonus increases by +1.
[b]Total Defense
You can defend yourself as a standard action. You get a +3 dodge bonus to your AC for 1 round. When your base attack bonus reaches +4, and every +4 thereafter, the dodge bonus increases by +1. Your AC improves at the start of this action. You can't combine total defense with fighting defensively, and you can't make attacks of opportunity while using total defense.
Acrobatics
Special: If you have 3 or more ranks in Acrobatics, you gain a +1 dodge bonus to AC when fighting defensively, and a +2 dodge bonus to AC when taking the total defense action.
Crane Style (Combat, Style)
Your unarmed fighting techniques blend poise with graceful defense.
Prerequisites: Dodge, Improved Unarmed Strike, base attack bonus +2 or monk level 1st.
Benefit: The penalty you take on attack rolls for fighting defensively is reduced by 1 point (minimum 0). While using this style and fighting defensively or using the total defense action, you gain an additional +1 dodge bonus to your Armor Class.
Crane Riposte (Combat)
You use your defensive abilities to make overpowering counterattacks.
Prerequisites: Crane Style, Crane Wing, Dodge, Improved Unarmed Strike, base attack bonus +8 or monk level 7th.
Benefit: The penalty you take on attack rolls for fighting defensively is reduced by 1 point (minimum 0). This reduction stacks with the reduction granted by Crane Style. Whenever you use Crane Wing to deflect an opponent's attack, you can make an attack of opportunity against that opponent after the attack is deflected.
In my home games, performing a combat maneuver does not provoke an attack of opportunity, but failing a combat maneuver leaves you flat-footed until the start of your next turn. Having the Combat Expertise feat, however, also allows you make an attack of opportunity against any opponent that attempts a combat maneuver against you without the Improved feat of that maneuver. If your AoO hits, the opponent takes the damage dealt amount as a penalty to their attack roll.
Also, in my games, the Improved maneuver feats (including Improved Feint) do not have Combat Expertise, Improved Unarmed Strike, or Power Attack as a prerequisite (they instead have just a +1 BAB and Ability score prerequisite), scale into the Greater version of that maneuver feat (at +6 BAB), and prevent you from being caught flat-footed should you fail the maneuver.
I've also rolled the Bull Rush, Drag, and Reposition maneuvers into the Grapple maneuver, replacing the 'Move' option of the Grapple maneuver with the 3-maneuver combo. This might be a topic for another post though if anyone is interested.
Fighting Defensively feels pretty pointless at low levels; at only a +1/-1, it's hardly worth the mental space to remember. I prefer starting any situational bonus at +2 or -2. Even a 1st level warrior is capable of fighting in a way that improves his defenses by a decent amount - he just might be bad at hitting people while doing it.
If Combat Expertise allows you to take AoOs against combat maneuvers, that should be mentioned in the feat description.
Giving a AoO against all combat maneuver attempts makes the divide between having Combat Expertise and not having it is pretty massive. What if that granted you an AoO against failed combat maneuvers?
Also, on the subject of combining combat maneuvers, have you considered combining Sunder and Disarm? The fluff of both is "I attack the opponent's item", and it seems like they would be easy to merge; just have the effect of Disarm while also dealing the damage of Sunder. It was always a little weird that items took no damage while being disarmed anyway.
You know what, the fighting defensively text there was taken from an out of date document (my original idea doc, not the refined thought doc), and I didn't even realize it. My apologies. I completely agree that -1/+1 was a little pointless, as to why I changed the feat to begin with.
It should read:
Fighting Defensively: You can choose to fight defensively when attacking. If you do so, you take a –2 penalty on all attacks in a round to gain a +2 dodge bonus to AC until the start of your next turn. When your base attack bonus reaches +4, and every +4 thereafter, the penalty increases by –1 and the dodge bonus increases by +1, to a maximum of -6 and +6.
Total Defense
You can defend yourself as a standard action. You get a +4 dodge bonus to your AC for 1 round. Your AC improves at the start of this action. You can't combine total defense with fighting defensively. You can make attacks of opportunity while using total defense, but you take a -4 penalty to your attack rolls. When your base attack bonus reaches +4, and every +4 thereafter, the penalty increases by –1 and the dodge bonus increases by +1, to a maximum of -8 and +8.
** The reduction granted by Crane Style and Crane Riposte also applies to attacks of opportunity when taking total defense. **
The version of Combat Expertise I posted is not from my home games, but one that is more a generic version for everyone to use.
Again, I must apologize as I didn't make it clear that failing a combat maneuver both provoked an attack of opportunity from your opponent, as well as left you flat-footed. Combat Expertise instead allows you to take that attack of opportunity before the maneuver, instead of when they fail.
The intent of the AoO before the combat maneuver was to keep the "damage taken = penalty to maneuver check" rule, as I liked the idea that even though you took a dagger to the gut, you were still able to grapple your opponent, or vice verse.
I sometimes allow a player to make a free disarm check when their sunder check hits, but fails to destroy the item. I also usually allow a free sunder attempt to an opponent's armor or shield on a critical hit (confirmation roll = sunder check result). But I haven't combined the two into one maneuver as you can still disarm an opponent without attacking his weapon, and just because you hit his weapon and damaged it with a sunder, that doesn't mean he always drops it.
I suppose merging the two could be done though, after thinking on it a little. When performing the maneuver, you decide whether to target armor, shield, or held item. If you target shield or held item, and your sunder attack hits, you roll a second time to see if you disarmed the opponent of the shield or held item.
Expanding this thought further, you could also add a disarm component to Grapple if you're unarmed... Looks like I will have to create another thread after all. Thanks Vadskye.
That looks like a much more useful version. I'd happily play in a game with this house rule.
I'm still worried that Combat Expertise is a bit too powerful. With both Expertise and the Improved/Greater feats for a maneuver, you're getting a +7 untyped bonus at 12th level and it is vastly harder to perform maneuvers of any kind on you. The fighting defensively scaling makes sense - it scales both the penalty and the bonus. But Expertise just doubly scales the bonus. I'm not sure that's a good thing.
You disarm an opponent without damaging the item, sure. Just make the player choose which effect he gets, but consider it part of the same maneuver. You don't have to drag an opponent in order bull rush them either, but I don't see a problem with putting those maneuvers together.
Do we need special rules for disarming in a grapple? You can already make attacks in a grapple, and "disarm" is considered an attack. I think it's already possible in the core rules without any need for extra rules.
And I'm glad I could help. :)