**1) Many things can trigger off it crits**,

*Special*stuff (listed below). I'm going to discount those as well and just focus on damage, but you should not.

2) It's not accuracy depenand. If you hit on a 11, weapon focus is worth 1.5, if you hit on a 2, it's worth 2.8. Crit's are worth the same no matter what (assuming you hit on an 18, which i am).

3) It's independant of your damage mod. It only maximizes dice, thus a 1d6 + 400 attack will see as much gain as a 1d6+1.

4) Can be wasted with overkill. The monster with 25 HP doesn't care that you did 80 damage when you rolled a 19 instead of 40, nor do minions. I know of no way of factoring this in, but simply put increasing your minimum damage is better then increasing your maximium damage (in the event of a tie, Weapon Focus wins).

I will be assuming 6d6 crit dice, with the 19-20 crit feat.

[sblock Math]

The equasion is (crit dice + max base dice - average base dice) * .05 (extra chance to crit).

Max = 2*(average-.5 * dice thrown), with a little factoring..

(21 + 2*(average-.5 * dice thrown) - average) *.05

(21 + 2*average- 1 * dice trown - average)*.05

(21 - dice trown + 2* average - average)*.05

[/sblock]

, we end up with...

**(crit dice (21) + average dice**

**- dice trown**)* crit expansion (.05)18-20 double the gain

17-20 tripple the gain

Avengers or other who get re-rolls (sage of ages) multiply by .09 instead of .05.

Base Gain WF hit rate*

d6's

7 (2d6) 1.3 .43

14 (4d6) 1.55 .52

21 (6d6) 1.8 .6

28 (8d6) 2.05 .68

35 (10d6) 2.3 .77

42 (12d6) 2.55 .85

49 (14d6) 2.8 .93

d12's

13 (2d12) 1.6 .53

26 (4d12) 2.15 .72

39 (6d12) 2.7 .9

Higher crit dice

HighCrit (d12) +.975

d8 +.3

d10 +.6

d12 +.9

Ring of Giants +.6

Bloodiron +2.25

"

*Special"*[sblock crit stuff]This is not exaustive, and many stack.

Epic Resurgence = regain an encounter

Two Weapon Opening = MBA

rending weapon/harmony blades = MBA

ardent champion = MBA

punisher of the gods = Standard Action

Rune of Battle = MBA for an ally.

Enabling Shot = MBA for an ally.

Glasya’s Charming Words = Dominate.

The Fading One - Touch from Beyond = Stunned.

Triumphant Attack = encounter long penalty.

[/sblock]

*The hit rate you need for Weapon Focus to add the same damage as the expanded crit range. (gain / 3)

**Conclusion**: Unless you have something

*special*(see above) that happens on a crit,

**weapon focus > expand crit range****. Of course more damage is more damage, but generally without something

*special*going on, it's not worth playing 20 levels worth of sub-par stats to get the 19-20 crit feat in epic.

**With high crit, or lot's of dice, expanded crit range will beat out weapon focus, but after factoring in overkill, it's still likely not worth it. You really need something

*special*.