Right, sorry for the delay.
99% of players in classic MSRD rules, when they "grapple" somebody, all they want to do is grab them. Stop them from moving, interfere with them in some way. Then the player wades through all the bloody options in the definition ... (the paralysing effect of too many choice, btw, has been well-documented) Only we grappling PC freaks really take the maneuver to town with our improved Grapple feats, etc. Same with Trip. When's the last time you saw somebody use Trip who wasn't decked out with the fun feats around it?
So they stripped it down. "Grab" is a standard action. -5 on the unarmed attack roll vs. Reflex DC, up to one size larger and one opponent at a time. It deals no damage. The -5, I assume because you're not just trying to hit a guy, but hit him somewhere -- arm, shoulder, waist -- where you can gain purchase. I am cool with that.
A "grabbed" opponent is at -2 for attacks (except w/natural and light melee weapons) , and can't move. You can take a standard action to break a grab automatically. That clears one grabber per character level. (So a heroic soldier can shake off the mooks trying to pin him down)
So when you grab somebody, they have a choice -- fight you, or stand there and try to keep shooting while you wrestle with them. (NOTE: I'd probably houserule that you can move the two of you around 1 square with an opposed STR check. I don't think you have to have somebody pinned to move them.)
A "Grapple" on the other hand, is essentially an improved Grab. You can only do it if you have the Pin or Trip feat or both. It's an unarmed attack (without the -5 penalty, so there's your Imp Grapple feat from the old rules, built in) that does no damage.
As soon as that attack's successful, make an opposed Grapple Check, with Grapple being:
d20+ BAB + (STR/DEX, pick higher) + special size modifier
If you win the Grapple check the result is dependent on your PC's chain of feats. That is, if you have Pin, the character's automatically pinned (no actions, lose Dex). Grapple every round to renew the pin. If you have Pin and Crush, you can choose to do unarmed damage at the same time as the Pin resolves. Trip feat: win the Grapple, your opponent's prone. Throw feat: the character's prone over there and takes unarmed damage. Essentially you're building a combat effect through a feat chain.
Or, when you win the Grapple check, you do damage with an unarmed strikes or light weapon.
Unless I'm misreading, if you're grappled and you don't have those feats, all you can do is make Grapple checks to try to get away. If you're subject to a Pin, I don't think you can use the Grapple check for unarmed/light weapon damage, since the feat explicitly says "may take no actions." And seeing as you're only Grappled by somebody who has the Pin feat -- you know what you can do and can't do. Automatically.
Now some people will freak, feeling options have been taken away from the character. I respect that, but disagree. I think close-up fighting is specialized enough that simulating it with some training is legitimate. I LIKE the idea that there's a difference between Schmuck A grabbing you, wrestling with you while you whack at him with your gun butt, and being able to put an opponent in a submission hold. As soon as you see a specialized grappling character, you know you are in for a world of hurt and had best stay out of arm's reach. At the same time, a specialized Grappling PC has a big advantage over untrained opponents, and won't take many feats before he's tossing Stormtroopers around like ragdolls or crushing their throats. Bull (Bantha, whatever) Rush has been similarly transformed into a feat -- not linked to Grapple, but same theory of design.
If you disagree, you can of course simply use the rules as stated in the feats Bantha Rush, Pin and Trip as combat choices, and leave Crush and Throw as feats. But this is one of those things I read and went "huh"?, and then on reflection realized I liked in the balance. You Grapple with clear intent now. And regardless, I love linking Trip to the Grapple roll. Tying previously separate maneuvers with separate rules to one game mechanic always pleases me.
