CMB Calculation

[LuceanThalavar]

Quote:

When you attempt to perform a combat maneuver,

make an attack roll and add your CMB in place of your
normal attack bonus. Add any bonuses you currently have
on attack rolls due to spells, feats, and other effects. These
bonuses must be applicable to the weapon or attack used to
perform the maneuver.

So ... what is applicable?

1 - maneuver bonus as written
2 - Charge gives a bonus to attack rolls and explicitly a +2 bonus on bull rush attempts; but is it in addition or did they just try to be clear cut in their writing?
3 - enchantments apply to attack rolls
4 - feats (e.g. weapon focus) apply to attack rolls
5 - class features like weapon training apply to attack rolls
... and there are surely other things

So, if I need a weapon with the trip property (I do, don't I?) to knock someone prone, I should apply its enhancement bonus and all the other stuff to it, since it is delivered with the weapon.

And further more, is CMB subject to BAB-reduction? In a full attack action I have my attack bonus reduced after the first attack (barring haste and similar stuff).

PS: There are really some parts in the book, where examples could have made everything so much easier :(

Thanks in advance

[Oladon]

PRD: Combat wrote:

When you attempt to perform a combat maneuver, make an attack roll and add your CMB in place of your normal attack bonus. Add any bonuses you currently have on attack rolls due to spells, feats, and other effects. These bonuses must be applicable to the weapon or attack used to perform the maneuver. The DC of this maneuver is your target's Combat Maneuver Defense. Combat maneuvers are attack rolls, so you must roll for concealment and take any other penalties that would normally apply to an attack roll.

The +2 bonus to bull rush is called out because you don't bull rush with a weapon, so you can't include any weapon-related bonuses (weapon focus, enchantments, etc.).

[Grick]

LuceanThalavar wrote:

So, if I need a weapon with the trip property (I do, don't I?) to knock someone prone

FAQ: "If you want to make a trip combat maneuver, do you have to use a weapon with the trip special feature? No."

Don't miss the link to the paizo blog post which has lots more information.

LuceanThalavar wrote:

I should apply its enhancement bonus and all the other stuff to it, since it is delivered with the weapon.

That's true of any weapon used to make a combat maneuver.

LuceanThalavar wrote:

And further more, is CMB subject to BAB-reduction? In a full attack action I have my attack bonus reduced after the first attack (barring haste and similar stuff).

Yes, for combat maneuvers that you can perform in place of an attack, you'll use the BAB for that attack in calculating your CMB.

[Grick]

LuceanThalavar wrote:

Charge gives a bonus to attack rolls and explicitly a +2 bonus on bull rush attempts; but is it in addition or did they just try to be clear cut in their writing?

This is probably just poor writing, but it doesn't stack.

Attacking on a Charge: "After moving, you may make a single melee attack. You get a +2 bonus on the attack roll and take a –2 penalty to your AC until the start of your next turn. A charging character gets a +2 bonus on combat maneuver attack rolls made to bull rush an opponent."

Bull Rush: "You can make a bull rush as a standard action or as part of a charge, in place of the melee attack."

Since the melee attack is replaced by the bull rush, you would also lose the +2 bonus on that melee attack (even though the bull rush itself is an attack roll!), so the extra line just makes sure that if you charge, you still get a +2 on the bull rush, because you're still charging even if you didn't make the melee attack the charge grants you.