# Do Blades of Death and Uncanny Blow stack with each other in any way?

Do the class features "Blades of Death" of the Master Samurai prestige class in Sword and Fist stack in any way with "Uncanny Blow" of the Exotic Weapons Master from Complete Warrior? Assume that the weapon being used is a bastard sword. I realize that Sword and Fist is from third edition but the Master Samurai seems to port directly to 3.5 without altering anything.

Here are the descriptions:

When the master samurai fights with the katana (bastard sword) two-handed, he adds double his Strength modifier to damage rolls.

Uncanny Blow:

When wielding a one-handed exotic melee weapon (in this case a bastard sword) in two hands, the character can focus the power of his attack so that he deals extra damage equal to his Strength bonus ×2 instead of his Strength bonus ×1-1/2. If he has the Power Attack feat, he treats the weapon as twohanded for purposes of determining his bonus on damage rolls.

• Neither of those can be used with a bastard sword? – SevenSidedDie Sep 11 '13 at 4:11
• It's only exotic one-handed. These feats require the use of two hands, in which case it is a martial weapon. – SevenSidedDie Sep 11 '13 at 4:34
• I don't see how a bastard sword changes to a martial weapon when it's used two-handed has anything to do with how these two class features may stack. – Helpless one Sep 11 '13 at 5:25

This is kind of awkward because of the way it is worded: neither ability says that you “double your Str bonus to damage” or similar, the verb is add not multiply. Strictly speaking, this does not trigger the usual multiplication rules, because the bonuses are separate things.

Moreover, at least from the quoted section, Master Samurai doesn’t seem to say that this addition is in replacement of the usual 1½ Str to damage. This implies an order of operations something like this:

Basic bastard sword damage when wielded in two hands:

1d10+1½Str

Replace the 1½Str with 2Str due to Uncanny Blow:

1d10+2Str

1d10+2Str+2Str = 1d10+4Str

More than likely, however, the idea in both cases was of replacement and multiplying the same Strength bonus to damage, triggering the multiplication rules as SevenSidedDie suggests

Basic Strength bonus damage is replaced by Strength modifier doubled twice, which in the usual D&D rules is ×3, like so:

1½Str -> (1+(2-1)+(2-1)Str = 3Str

In any event, one or the other of these is certainly how the combination is supposed to work, and there’s nothing to suggest they shouldn’t be combined. So just ask your DM which calculation he wants to use. Personally, since I see all of the classes involved here as extremely underpowered, I probably wouldn’t object to the ×4, but the ×3 is probably the more reasonable interpretation of the intent if not the wording.

Note that in order to use both, though, you will need to treat the bastard sword as a one-handed exotic weapon, which you can only do with the Exotic Weapon Proficiency feat (or taking the nonproficiency penalty). This isn’s a big deal since Exotic Weapon Master requires that you have the feat in any event. You are never required to treat a bastard sword as a two-handed martial weapon; it’s just an option for getting around the nonproficiency penalty if you want. You may treat it as an exotic one-handed weapon any time you choose to, even if you choose to do so while using two hands.

Yes, they can stack. Multipliers have standardised rules for how they stack, covered in the d20 SRD in The Basics: Multiplying:

When two or more multipliers apply to any abstract value (such as a modifier or a die roll), however, combine them into a single multiple, with each extra multiple adding 1 less than its value to the first multiple. Thus, a double (×2) and a double (×2) applied to the same number results in a triple (×3, because 2 + 1 = 3).

So multiples are additive and then multiply the abstract value, they don't multiply each other. In this case, that means that when you have two effects that "double your Strength modifier" or "Strength bonus ×2", you get 2 + (2 - 1) = 3 for a final multiplier of ×3.

Note however, that Uncanny Blow can't be used with a bastard sword, because it is a two-handed martial weapon when used with two hands, while the feat requires you to use, with two hands, a one-handed exotic weapon that stays a one-handed exotic weapon when used with two hands.

• Why can't Uncanny Blow be used with a bastard sword? The bastard sword is an exotic weapon. Just because you two-hand it doesn't mean it is no longer exotic, all it says is that a character can use it as a two-handed martial weapon. So, if the character is proficient in martial weapons then he can use it, but the weapon is still exotic. The wording for "Exotic Weapon Trick" also does not disqualify bastard swords from being chosen. – Helpless one Sep 11 '13 at 6:34
• @Helplessone Actually, two-handing it is exactly what makes it not exotic. See its description in the SRD (scroll down to "Sword, Bastard"). Used two-handed it is a martial weapon. Because it requires training to use one-handed it counts as exotic when one-handed, but two-handed it is a plain martial weapon. Since this feat requires using it two-handed, as soon as you do use it two-handed it is a martial weapon and doesn't qualify for the feat. – SevenSidedDie Sep 11 '13 at 14:58
• @KRyan I stand by my reasoning. Nothing can be both exotic and martial at the same time; it's one or the other. HO is welcome to take the info on multipliers and ignore the note if their judgement firmly disagrees. – SevenSidedDie Sep 11 '13 at 15:09
• I don't believe "I stand by my reasoning" ought to give any impression of interest in discussion. – SevenSidedDie Sep 11 '13 at 15:23
• Uncanny Blow: "When wielding a one-handed exotic melee weapon in two hands." For the bastard sword to be a one-handed weapon, it must be exotic. It does not automatically become a martial weapon as soon as you put a second hand to it (it arguably does not do that in any event), you merely can choose to treat it as a martial two-handed weapon. You can choose not to, and treat it as an exotic one-handed weapon you happen to be wielding in two hands. – KRyan Sep 11 '13 at 15:27