DFI bard and D&D math [3.5]

[gomipile]

I was explaining the Dragonfire Inspiration bard to a friend, and he balked at the way Words of Creation works.

He says that because of D&D's multiplication rules, Words of Creation would only multiply the bardic music bonus from bard levels, and not the bonus Song of the Heart or Inspirational Boost.

Specific, unarguable quotes one way or the other on this, and preferably encompassing precisely when the weird "D&D multiplication" rule does and does not kick in would be appreciated.

[Zaydos]

Well going to page 32 of the Book of Exalted Deeds... I'm not sure if I can directly quote it.

It says it doubles the bonus, and then lists the new bonus by level in parenthesis.

So I don't really know myself.

[Douglas]

"D&D multiplication" comes into play specifically when multiple multipliers are in effect. x2 and x2 = x3 instead of x4. This is a completely and totally separate issue from whether you add before multiplying.

I don't think there is any true RAW quote sufficiently explicit to unequivocally satisfy your friend on this issue. There is a quote from the official FAQ about applying modifiers in the order most beneficial to whoever they belong to that you might be able to use, but it's only the FAQ rather than errata or other RAW, and the specific question it's addressing in context is the interaction of resistance and vulnerability to energy damage.

[kestrel404]

From BoED:
A bard who has the Words of Creation feat can use these powerful words
to enhance his bardic music ability as detailed below.
...
The Words of Creation doubles the effect of several bardic music abilities:
* Inspire courage: Double the morale bonus on saving throws against charm and fear and the morale bonus on attack and weapon damage rolls.
...

From Eberron Campaign Setting:
Song of the Heart
Benefit: When you use inspire courage, inspire competence, inspire heroics or inspire greatness, any bonus you grant is increased by +1.

The wording on other abilities that grant boni to inspire courage are similar or identical, except where they instead increase your effective bard level.

D&D multiplication says that static values are added before multiplication. The weird multiplier rules only come into play in certain conditions if you're increasing your multiplier beyond x2. I can't quote those rules, though.

[Zaydos]

Well if we can quote the book directly, then let's give the whole quote.

The Words of Creation doubles the effect of several bardic
music abilities:
• Inspire Courage: Double the morale bonus on saving throws
against charm and fear and the morale bonus on attack and
weapon damage rolls (+2 at 1st level, +4 at 8th level, +6 at 14th
level, +8 at 20th level).

The edited out part does possibly matter. Although yes, the normal rule is addition before multiplication in D&D so I'd still say that you'd multiply everything by RAW.

Also the D&D multiplying rules from page 304 of the PHB:

Spoiler

Show

MULTIPLYING
Sometimes a special rule makes you multiply a number or a die roll.
As long as you’re applying a single multiplier, multiply the number
normally. 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).
For example, Tordek, a high-level dwarven fighter, deals 1d8+6
points of damage with a warhammer. On a critical hit, a warhammer
deals triple damage, so that’s 3d8+18 damage for Tordek. A magic
dwarven thrower warhammer deals double damage (2d8+12 for
Tordek) when thrown. If Tordek scores a critical hit while throwing
the dwarven thrower, his player rolls quadruple damage
(4d8+24) because 3 + 1 = 4.
Another way to think of it is to convert the
multiples into additions. Tordek’s critical hit
increase his damage by 2d8+12, and the
dwarven thrower’s doubling of damage
increases his damage by 1d8+6, so both of
them together increase his damage by 3d8+18
for a grand total of 4d8+24.
When applying multipliers to real-world
values (such as weight or distance), normal rules
of math apply instead. A creature whose size doubles
(thus multiplying its weight by 8) and then is turned to
stone (which would multiply its weight by a factor of
roughly 3) now weighs about 24 times normal, not 10
times normal. Similarly, a blinded creature
attempting to negotiate difficult terrain would
count each square as 4 squares (doubling the cost
twice, for a total multiplier of ×4), rather than as
3 squares (adding 100% twice).

[kestrel404]

The bonuses listed in BoED are simply assuming the normal inspire courage progression without any enhancers - which is completely understandable, since the BoED was published before there WERE any other enhancers - MIC, SPC and ECS (the three sources that gave us Badge of Valor, Inspirational Boost, and Song of the Heart respectively) were all published well after BoED. Even the DMG2, which gets us the Hero's Vest (or whatever, +5 effective bard level item) came a lot later. So Words of Creation was the first bardic music enhancer, and thus stated the expected new bonus.

Of course, any sane GM would change the way Words works anyway, since doubling bonuses like that gets very silly and you can get ALL of those bonus enhancements very early on (you can have everything but the vest at level 3, giving you a possible +8 inspire courage).