Two-Weapon Fighting and associated feats [GodsBlood]

[RedWarlock]

Rules note: Critical hits maximize the weapon damage. Some weapons have a crit-multiplier, meaning the maxed damage is multiplied by 1.5 (for x3 crit weapons) or by 2 (for x4 crit weapons). Bonus damage (energy on weapons, sneak attacks & other bonus dice) is still rolled normally.

Excerpted and updated from an old TWF fix thread on Homebrew:

Base Rules (no feat):
When fighting with two weapons, you can choose to take a -4 to the attack roll with your main hand (-6 if the off-hand weapon isn't light) in order to add your off-hand weapon to the damage with your main hand as bonus damage dice, and deal damage as if using a two-handed weapon (2x Str bonus). Both weapons must be in reach of the target of this attack. Attacks are made with the main-hand weapons' attack roll, dealing damage with both weapons' damage types. Critical hits are scored with the lesser of the two critical ranges, maximizing the main-hand weapon's dice. The greater of the two critical multipliers are applied to the main-hand damage as well as the flat numeric bonuses, but not the off-hand damage dice. Special properties only apply from the main-hand weapon, though the off-hand weapon retains its damage type.

You can also choose to use only one weapon at a time, taking no penalties but gaining no bonus damage or increased handedness from the other weapon. You can still make single attacks with either weapon at no penalty.

Two-Weapon Fighting [General]
Prerequisite
Dex 15.

Benefit
Whenever you would be able to make a single attack, you can take a -2 penalty to your attack (-4 if the off-hand weapon isn't light) in order to make two attack rolls, one for each weapon; a primary attack with your main-hand weapon, and a second attack roll using your off-hand weapon. Both attacks add all the same situational penalties and bonuses to each attack roll.

The number of swings gained from BAB is doubled; the first half going into a 'main-hand' pool which can only be used for main-hand actions, the other half going into an 'off-hand' pool for off-hand actions. Bonus swings gained from other sources, such as Combat Reflexes, can be spent for either hand.

Alternately, you can still make a combined strike using both weapons, removing the -4 penalty to the attack roll for the single attack. If the off-hand weapon isn't light, this is only reduced to a -2 penalty. Retries using this technique cost a swing from each pool.

Two-Weapon Defense, Improved and Greater TWF, and any other such derivations are removed.

[Garryl]

The multiplier on maximized crits for high crit weapons, does that apply to just the variable damage component of the weapon, or to bonus damage as well (like Strength, Power attack, enhancement bonuses, etc.)?

Ignoring the off-hand's critical threat range/multiplier means that players are incentivized to only use weapons with a high base damage in the off hand, and to only care about critical for the main hand. A short sword is just as good as a sickle and both are better than a kukri.

Wait a sec, why do the base rules work so differently from the rules when you have the feat? That's confusing.

How does the combined strike thing work when your two weapons have very different properties (such as a glaive + armor spikes where they don't even threaten the same spaces, or just a mace + a kusari-gama for non-reach + spiked chain-type reach)?

[RedWarlock]

The multiplier on maximized crits for high crit weapons, does that apply to just the variable damage component of the weapon, or to bonus damage as well (like Strength, Power attack, enhancement bonuses, etc.)?

Flat bonus damage, though not extra dice of damage. (I was debating making it extra dice on a crit, as the 4e Heavy Crit property, but I'm not sure.) Keep in mind this isn't a straight conversion, just general guidelines, since I'll have to tweak weapons to deal with the extra properties I'm adding in.

Ignoring the off-hand's critical threat range/multiplier means that players are incentivized to only use weapons with a high base damage in the off hand, and to only care about critical for the main hand. A short sword is just as good as a sickle and both are better than a kukri.

Hmm, perhaps you're right. I was debating making it something like, 'Use the lesser of the two critical ranges, and the greater of the two critical multipliers', or vice versa, but I was thinking that might be too complex. (Edit: Did that, let's see how it works.) My first instinct is to say that each weapon scores criticals based on their own threat range based on the single die roll, but that might be too incremental and complex for the base rule. (I forgot to mention that I also don't use crit-confirm, just straight crit==max damage.)

Wait a sec, why do the base rules work so differently from the rules when you have the feat? That's confusing.

What seems different, exactly?

The idea here is that the base rules are a simple bonus of damage, whereas the feat adds optional complexity and the ability to do more with it, IE, get separate attacks and the swings to go with them. The part with the swings rolls in TWDefense into the base functionality, because those swings can be used for parries/blocks. (For instance, normally, if you're using a shield, you have to spend your base swings to block attacks, whereas with this feat, you can more effectively block with that shield.)

And actually, that kind of functionality makes me wonder if I just want to re-name it Ambidexterity, since it has as much to do with arms operating independently as it does actual pairs of weapons...

How does the combined strike thing work when your two weapons have very different properties (such as a glaive + armor spikes where they don't even threaten the same spaces, or just a mace + a kusari-gama for non-reach + spiked chain-type reach)?

Good point, I'll clarify in the base post. The quick answer is that both weapons have to be in reach of the target. (this is also important because I'm going to be altering default reach, making smaller weapons like armor spikes and daggers have reach 1, medium weapons like maces and longswords reach 1-2, big weapons like greatswords and short  polearms (halberds, spears) have reach 2-3, and long polearms (longspear, glaive) have reach 3-4, with maneuvers/abilities that allow you to short-haft inside your reach or lunge to get outside your normal reach. (my base unit is also a yard rather than 5ft.)