[Fantastic Dungeon Grappling] Defending while grappling
 

If a monster bites and holds on, does this penalize their defenses? Can they parry normally?

Or if it uses an appendage like a tentacle? Does it have a penalty on a parry?

Does the victim get a bonus to hit the grabbing appendage?

Re: [Fantastic Dungeon Grappling] Defending while grappling
 

You cannot parry with the limb used to grapple. However, TG and Martial Arts both allow "hands-free" parries that involve (basically) yanking on the other guy, or shifting yourself, using contact and body mechanics. So they can usually do a grappling parry, but not (say) a weapon parry.

For the bite case, I'd say "yeah, they can parry normally using a grappling skill."

Same answer. You cannot parry with the tentacle, but can do a hands-free parry.

In practice, this means Monster (M) grapples character A. M may parry attacks by A using a full-skill grappling parry. Character B tries to kill M with a sword. M may NOT parry using the grappling limb (or teeth) and must release the grapple to do so.

That's how I run it, but other interpretations are valid.

No. The only "bonus" you can usually collect is the usual halving of hit penalties for a grappling attack.

Re: [Fantastic Dungeon Grappling] Defending while grappling
 

How about using character A to parry with?

Re: [Fantastic Dungeon Grappling] Defending while grappling
 

Covered! Check out Human Shield on p. 8

Re: [Fantastic Dungeon Grappling] Defending while grappling
 

Thanks Douglas! Your rulings sound reasonable.

Re: [Fantastic Dungeon Grappling] Defending while grappling
 

I also went back and did a careful read of "What is a Parry" from Martial Arts, and the expanded discussion of it in the original Technical Grappling book. If you have access to both, they're worth that careful read.

Re: [Fantastic Dungeon Grappling] Defending while grappling
 

Conceptually it feels kinda weird that as a human I could bite a guy's leg and this wouldn't at all inhibit my ability to fend off his punches using my hands or dodge attacks aimed at my head without letting go.

Re: [Fantastic Dungeon Grappling] Defending while grappling
 

You'll have penalties for posture if you can't reach his leg while standing up.

Re: [Fantastic Dungeon Grappling] Defending while grappling
 

This is what a GM is for.

Re: [Fantastic Dungeon Grappling] Defending while grappling
 

A "parry" or even "dodge" in this context can just as easily represent using your bite grip to take your enemy off-balance enough that the attack misses, shifting your own body into place so that a shoulder deflects the blow harmlessly, or even letting go for a split second to move and reestablishing the bite. The defense roll represents 'a result that means you take no damage and maintain your grip', not any specific action like directly slapping a punch aside with your hand.