My girlfriend was reading through this, and asking me about it, so I tried vainly to remember highschool math, and try to run the numbers.. I'd appreciate any thoughts on where and how I screwed up
Single Longsword Attack- 1d20 + BAB. 12DMG.
TWF Feat- Two attacks, One at 1d20-4, the other at 1d20-4. D8 each.
Attacking someone who is AC 11. 1st level fighter. +1BAB. Strenth of 18, so +4.
Long Sword (LS)- Must Roll a 10 or Higher. 55% chance of doing 1d8 dmg.
(you hit on 11/20 results)
TWF- Two chances to roll a 14 or higher. 35% chance each of doing 1d8 dmg.
(you hit on 7/20 results)
Two 35% chances are above one 55% chance. This means that TWF has a higher base chance to hit, and higher maximum damage.
Best case LS- 8. Best Case TWF- 16.
TWF comes out ahead, as it should, as it requires the expenditure of a precious feat.
Adding in Strength Damage continues the pattern. The LS will now get 1d8+4. The Second Sword of TWF only get's .5 strength damage. As either weapon is equally likely to hit, we'll give them .75 strength damage. That gives the TWF average 1d8+3.
Two weapon Fighting is beginning to look less impressive. The reduced strength damage on average hurts.
The average damage done is Base chance to hit, applied to the average damage.
The average damage of a Longsword (1d8) is 4.5.
LS- 55% (4.5 + 4) = 55% (8.5) = 4.675 dmg/hit
TWF- 35%(4.5 + 4) + 35%(4.5 + 2)= 35%(8.5) + 35% (6.5) = 2.975 + 2.275 = 5.25 dmg/hit
This math (if it's right) shows that TWF continues to give a great advantage in the probability to do damage each hit, as well as increasing the Maximum damage.
Maximum LS damage- 8+4=12. Maximum TWF Damage = 8+4+8+2 = 22.
You would be doing 96% more damage in the best case.
So it would seem that the TWF feat allows you to optimize for the best case, while lessening your chances at the average damage. While this is a valid choice, I'm not sure that it is worthy of a feat. But it does still allow people to do more maximum damage than they would otherwise, so it's a toss up.
Now, let's add Power attack into the mix.
Single Sword Powerattacking for 1. This gives the single attack a 50% chance of hitting(10/20).
For the sake of simple numbers, let's pretend that you can powerattack more than your BAB, to show the trend upward. Powerattacking for Two would require a 12 (9/20) for a 45% chance to hit.
LS P1- 50%(4.5+4 +1 ) = 50%(9.5) = 4.75
LS P2- 45%(4.5+4 +2 ) = 45%(10.5) = 4.725
LS P3- 40%(4.5+ 4 + 3) = 40%(11.5) = 4.6
So PowerAttacking for one, as you are supposed to be able to, improved your average damage. For the sake of thoroughness, let's do the same chart assuming a BAB or +2.
Now, a long sword requires a 9 to hit. (12/20 results)
LS - 60% (4.5+4) = 60%(8.5) = 4.8
LS P1- 55%(4.5+ 4 + 1)= 55%(9.5) = 5.225
LS P2- 50%(4.5 + 4 +2) = 50%(10.5)= 5.25
So, by this math, again, assuming I'm not a freaking idiot, which I suspect I am, you would need a matching feat (One char gets Power Attack, the other gets TWF) AND a BAB increase to match the power of TWF.
But, to bring this back to more relevance, you can use a Great Sword, if you only have one weapon, which changes everything.
The Greatsword get 2d6 damage, and also gets 1.5 STR. We'll go back to our BAB of +1.
GS- 55% (7 + 6) = 55%(13) = 7.15!
Wow.. Now, this gets even more impressive if you use Powerattack
GS P1 50%(7+ 6 + 2) = 50% (15) = 7.5!
Ok. So This means that the TWF route only does 70% of the damage of the Great Sword. ((5.25*100)/7.5x)
The difference in maximums has also been reduced.
Maximum LS damage- 8+4=12.
Maximum LS P1 Damage = 8 + 4 + 1 = 13.
Maximum TWF Damage = 8+4+8+2 = 22.
Maximum GS Damage = 12 + 6 +2 = 20
So at this point, if you go TWF, you are gaining a 9% increase in Total Damage, but Losing 38% of average damage. Doesn't sound like a very tempting prospect.
But let's try taking Critical hits into account.
Both a LS and a GS crit on a 19-20, for x2. (On a side note, this makes the prospect of using a LS a bit limiting, as a GS seems to be better is Most categories..)
The GS has a 10% chance to do double damage, including all added strength. Which means we can add One Tenth of the total sum (from above), to the Current Average Damage per round.
GS, Adjusted for Crit- 7.15 + .715= 7.865
For the TWF, each weapon has a separate chance to crit, so the extra critical damage must be calculated separately.
TWF- Attack 1- 35%(4.5 + 4)= 2.975
Attack 2- 35%(4.5 + 2) = 2.275
Attack 1, Adjusted for Crit = 2.975 + .2975 = 3.2725
Attack 2, Adjusted for Crit = 2.275 + .2275 = 2.5025
TWF, Adjusted for Crit = 5.775
(Granted, this comes out the same mathmatically as 5.25 + .525, but I'm trying to break everything down as much as possible)
Well, at this point, we have TWF up to doing 73% of the Great sword.. But it's still nothing to write home about.
Perhaps this could be countered by giving all TWF users TWD? This would give you a +1 to your AC, while you have the set of swords out.
Then let us put the two people in Battle, Each having a BAB of 1, and an AC of 10. Because Mr. TWF has his second weapon out, his AC will raise to 11.
GS attacking TWF+TWD - Needs to Roll a 10. 55% chance to hit. 55%(7 + 4) = 6.05 dmg/hit
TWF+TWD attacking GS- Needs to Roll a 13 on each. 40% chance to hit. 40%(3.5 + 4) = 2.8; 40%(3.5 + 2) = 2.2.. = 5 dmg/hit
Adding Crits-
6.05 + .605 = 6.655
5 + .5 = 5.5
In this instance, the GS Advantage is still present, but the GS is only doing 17.3% damage than the TWF style. Still Ahead, but not nearly as far.
As others have discussed, this will only get worse as the GS user gets multiple attacks, the the TWF user does not gain additional attacks with the second weapon.
Even if we were to reduce the Great Sword to critting only on a 20, then we would reduce it's extra damage per round by half. That would reduce it's damage per round to 7.5 per round on average, or 6.35 per round against the better AC of the TWF. It's still doing 13.38% more damage. Not enough of a change. Let's discard that idea..
This would seem to be a difficult problem to solve. Another Solution, of course, would be to restore the Full Strength damage to handed weapon in a TWF attack.
That would give us
TWF- 35%(4.5 + 4) + 35%(4.5 + 4)= 35%(8.5) + 35% (8.5) = 2.975 + 2.975 = 5.95
+ .595 = 6.545 dmg/hit
If we combined that, with adding in TWD to TWF, we'd be left with the two facing each other
TWF+TWF- 6.545
GS- 6.555
Which is much closer to where things should be. Keep in mind, however, that the Two weapons user would have still spent a feat (or, if we aren't combining TWF and TWD) Two feats, to keep up with the Base GS attacker.
To try to conclude, It seems that that the difference isn't that a Great Sword does more damage than Two Weapon Fighting, but that if you are using TWF, you must use medium weapons, where a single weapon fighter could use a larger weapon.
When putting the Long Sword against the Two Weapon Fighting fighter, Two Weapon Fighting won handily.
But any fight between a LongSword and a GreatSword is heavily biased towards the Great Sword user. Two Weapon fighters are forced to use the smaller weapon, and will thus be at a disadvantage, even with regular attacks..
Thoughts? Care to explain the numerous places I screwed up on my math? Or even tell me I have a basic misunderstanding of D20 combat?
Colin
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