Grappling Party (Grappler) vs Grappled Party in Concentration Checks

[Abombom]

Pathfinder grappling rules wrote wrote:

If You Are Grappled

If you are grappled, you can attempt to break the grapple as a standard action by making a combat maneuver check (DC equal to your opponent's CMD; this does not provoke an attack of opportunity) or Escape Artist check (with a DC equal to your opponent's CMD). If you succeed, you break the grapple and can act normally. Alternatively, if you succeed, you can become the grappler, grappling the other creature (meaning that the other creature cannot freely release the grapple without making a combat maneuver check, while you can). Instead of attempting to break or reverse the grapple, you can take any action that doesn’t require two hands to perform, such as cast a spell or make an attack or full attack with a light or one-handed weapon against any creature within your reach, including the creature that is grappling you. See the grappled condition for additional details. If you are pinned, your actions are very limited. See the pinned condition in Conditions for additional details.

In a grapple, both parties involved gain the grappled condition. Yet, it's often referenced, as in the case of the quote above, that there's a grappler (the one currently winning the grapple) and implied that there's the grappled (the one currently losing the grapple).

Pathfinder wrote:

Casting a spell while you have the grappled or pinned condition is difficult and requires a concentration check (DC 10 + the grappler’s CMB + the level of the spell you’re casting). Pinned creatures can only cast spells that do not have somatic components.

When in a grapple, are both parties considered the "grappler" for purposes of the above quote?

If I am involved in a grapple, win the grapple, and attempt to cast a spell, do I add the losing party's CMB even though I am the grappler?

[Nefreet]

If you're the "Grappler" you never have a chance to cast a spell, since you've likely already used your Standard Action.

If you have Greater Grapple, where maintaining is just a move action, then I suppose the only DC that makes sense would be using the CMB of your opponent.

Probably wouldn't want to use yours, since it's probably higher.

[Abombom]

Nefreet wrote:

If you're the "Grappler" you never have a chance to cast a spell, since you've likely already used your Standard Action.

Assume that quickened spells, Greater Grapple, Rapid Grappler, or other such things are in play.

[Nefreet]

I didn't edit my comment =\

[Gwen Smith]

Abombom wrote:

When in a grapple, are both parties considered the "grappler" for purposes of the above quote?

If I am involved in a grapple, win the grapple, and attempt to cast a spell, do I add the losing party's CMB even though I am the grappler?

The grappler is the one controlling the grapple, the one that has the ability to release the grapple as a free action.

Which, if you win the grapple and want to cast a spell, is probably your best bet: release the grapple as a free action, five foot step, and cast your spell without a concentration check. If you choose not to do that, I'd use the CMB of the party currently controlling the grapple for the concentration check.

Of course, as other people pointed out, you'll need to have some way of taking two standard actions in the same round (Greater/Rapid grapple to make the grapple check not a standard action, or Quickened/War priest fervor/something else to make the spell not a standard action).