Driving in to work, I wondered if I was looking at a worst case scenario. So I ran some numbers this morning. Please keep in mind that here I'm looking at a 20th level character, and I haven't given any thought to balance at lower levels.
Take a 20th lvl variant ranger PC with a +5 str bonus, +5 magic bow, +3 misc damage due to misc feat bonuses or magic items, and a +10 to dmg vs. his worst foe. Assume rapid shot.
Traditional full attack archery:
- A normal arrow averages about 16 pts dmg, or 96 pts with a full attack when all hit.
- A full attack with one crit does 107 pts. (Usually not all 6 will hit, though.)
- A normal arrow vs a ranger foe does 34 dmg, or 204 pts with a full attack when all hit.
- A full attack with one crit does 216 pts. (Usually not all 6 will hit, though.)
- Only the crits trigger massive damage saves.
Using Diamond Arrow with the 9th lvl strike and either a x2 or x3 stance:
- A normal 9th lvl strike does 57 pts, 114 on a x2 stance, and 171 on a x3 stance.
- A normal 9th lvl strike vs a ranger foe does 67 pts, 134 on a x2 stance, and 201 on a x3 stance.
- A critical hit 9th lvl strike does 171 pts, 228 on a x2 stance, and 285 on a x3 stance.
- A critical hit 9th lvl strike vs a ranger foe does 201 pts, 268 on a x2 stance, and 335 on a x3 stance.
- Every successful shot triggers a massive damage save.
- With no iterative attacks, the arrows are more likely to hit.
- Barring feats, this 9th lvl maneuver can only be performed once per encounter; other maneuvers will do less damage.
My conclusion: those multipliers cause the biggest imbalance.
And since I hate to point out problems without a possible solution...
My change would be making the x2 stances grant x1.5, and making the x3 stance grant x2.
Okay - where'd I screw up in my analysis?