Infiniti2000 said:
Well, I personally assume an unweighted distribution unless otherwise specified.
Which is fair given the lack of specificity in the RAW, but it rubs me the wrong way that if my Medium-sized dwarven friend is being grappled by a Large Bear or Huge Fiendish Centipede that I have an equal chance of hitting him or the much larger beast with my arrows. At least if you add in some ratio accounting for size differences you can approach something more realistic, IMO, and usually to the party's benefit.
Since the dwarf and bear share the same four squares, IMC we give a 25% chance to hit the dwarf and a 75% chance to hit the bear (usually rolling a d8 and hitting the dwarf on a roll of 1 or 2).
However, if the bear has grappled the dwarf using Improved Grab then, because the bear isn't considered grappled itself, there's no chance to hit the dwarf.
Similar math with 9 squares for a Huge Fiendish Centipede we've agreed to fudge a bit to keep the math manageable at the table and go with another d8, but only hitting the dwarf on a roll of 1.
Those are purely House Rules, but the tend to help the party substantially more than any monsters/oppenents since generally it's the Small & Medium-sized party members being grappled by Large, Huge, etc. monsters.
Oh, and it doesn't really slow down gameplay any more than a miss chance from concealment or something like that. Just roll an extra d8 with attack and damage dice and check it first.
Thanks,
DrSpunj