Quote Originally Posted by The Mentalist View Post
*cough*Splitting*Cough* (Yes, almost universally considered cheese but worth mentioning when we're talking about such massive amounts of attacks.)
Splitting is considered cheese? as it's a +3 enhancement, I've always felt it a fairly balanced option that makes ranged weapons actually viable. I didn't include it because I didn't want to muddy the math with (minor) optimization.

Quote Originally Posted by The Mentalist View Post
The break point comes even sooner than that in my mind though. Even without Haste, Splitting, or any other multiple attack method you end up with 18 attacks at level five (admittedly all at -4 penalties but that's still 12 with -2 FAR better than two weapon fighting ever gets and much more quickly [I know TWF is not a balance point]) With any Negative level or stat damage option this becomes absurdly powerful.
18? I'm seeing:
  • 2 from +6/+1 BAB
  • Up to 4 from Rapid Shooting
  • Multishot doubles that to 8, since you can only add one arrow at this point.

Still way to much though! Deadly skill already gives a huge damage boost per arrow, which also probably needs to be toned down.

Quote Originally Posted by The Mentalist View Post
This is a good concept and having a volley attack archer is a really cool idea and archetype the multiplicative method may not be the best option for this as Mammon so eloquently showed (as the attack progression scales quadratically and health for everything scales in a linear fashion)

I am not entirely sure how to make the Volley archer viable without being OP yet but I'll get back to you if I think of something. (Possibly scaling back the multiples or giving one point of multiplication that scales up (x2 to x3 to x4 to x5) or something like that.
It might be worth looking at the Volley rules from Heroes of Battle (page 68).