Bonus to damage rolls question

[DarthPeleus]

My DM is convinced that any text reading something along the lines of "bonus to damage rolls" (Power attack, STR mod) will add the number for each die when calculating damage.

Ex
Bob attacks with a greataxe at STR mod +1. Damage= 1d12+1
Bob attacks with a greatsword at STR mod +1. Damage= 2d6+2
Enlarged greatsword 3d6+3
etc.

Is this true? The MM and stat blocks and such seems to suggest otherwise. Seems to balance melee out when you do this however.
Tried to find an example in the PHB but no luck :(

Thanks guys!

[NeoSeraphi]

Not true at all. Bonus damage comes like this:

Light weapon in off-hand: Half Strength, 0 Power Attack

Light weapon in main hand- 1x Strength, 0 Power Attack

One handed weapon in main hand- 1x Strength, 1x Power Attack

One handed weapon in both hands, Two-handed weapon- 1.5x Strength, 2x Power Attack

[DarthPeleus]

Not true at all. Bonus damage comes like this:

Light weapon in off-hand: Half Strength, 0 Power Attack

Light weapon in main hand- 1x Strength, 0 Power Attack

One handed weapon in main hand- 1x Strength, 1x Power Attack

One handed weapon in both hands, Two-handed weapon- 1.5x Strength, 2x Power Attack

Oops. Forgot to account for the two hander thing. But thank for the reply.

I now remember one of his arguments being that dragons couldn't hurt each other without the multiple damage dice thing, but now that I look up dragon, they pierce their own DR anyway.

[Hashmir]

Yeah, with a greatsword, 2d6 is the damage roll. Otherwise, you'd be seeing greatsword-wielding Strength rogues Power Sneak Attacking crap all over the place.

(I'm sure there are a million more broken things that happen with your DM's reading, but this was the first core-only problem that occurred to me.)

EDIT: A concise way of putting it would be that each attack roll corresponds to exactly one damage roll. (There may be some exceptions.)