Grapple Checks and being stunned

[KatCa]

Hello, I had a game situation come up today. I used color spray and stunned my target. I then went to tie him up, but the GM had me do a grapple check against the target's CMD. I then had to do another check the next round to pin. Next round I had to do another check (which I faailed) to tie him up. My question is, do you have to do all those opposed checks against a stunned creature? Thx.

[Brother Fen]

A stunned creature is not considered helpless, so it still can resist, with penalties. So, your GM was correct. If it was "helpless" from being unconscious for example, rather than stunned, no roll would have been needed.

[Kayerloth]

Namely it will lose any Dex bonus to its CMD. And I would probably say you should get another +2 to your CMB (+/- other drm's) per this bit, bolding mine:

CRB, Combat Manuevers 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.