Two Weapon Fighting 8

You can rend once per full attack. To rend an opponent, both attacks must be delivered as part of the same action. So unless you can make a full attack as an attack of opportunity (Combat Reflexes 9), you can't rend on an attack of opportunity.

Two Weapon Fighting 9

Q: Two Weapon fighting mastery may need looking into (e.g. TWF9 where you get all your extra secondary attacks but not primary ones? Bug or feature?)

Feature: it’s designed to reward those who have invested other feats in the TWF feat chain. Basing it on off-hand attacks rewards those with TWF 4 and 7, whereas basing it on primary attacks would mean anyone with TWF 1 would get the full bonus.

Note that TWF9 gives you no benefits when making an Attack of Opportunity: you make one single attack for the Attack of Opportunity.

Two Weapon Fighting and (other game mechanics)

Two Weapon Fighting generates a lot of questions about how it interacts with other feats, skills, and particular types of equipment. Below is a list of links to all such questions.

• Attacks of Opportunity
• Bastard Sword
• Double Weapons
• Improved Shield Bash
• Rapid Shot
• Razor Fiend
• Trident Mastery
• Unarmed Combat Mastery
• Weapon Descriptors