Majere said:
Ok basic number crunch.
Lv 20 fighter, with 30Str, WF,WS,IWF,IWS, IC., PA
THF using a greatsword (+5)
TWF using a double sword (+5/+5)
THF:
(+37/+31+27+22), 2d6+19
TWF:
(+35/+30/+25/+20), d8+14
(+35/+30/+25), d8+9
Damage quoted as:
Without PA (With optimal PA)
Enemy ac 40:
THF: 65.325 (66.04)
TWF: 65.04 (66.9)
Enemy ac 35:
THF: 90.48 (105.72)
TWF: 99.84 (110.55)
Enemy ac 30:
THF: 107.64 (148.68)
TWF: 124.8 (165.6)
Enemy ac 25:
THF: 117 (197.01)
TWF: 140.16 (224.64)
Enemy ac 20:
THF: 118.56 (251.82)
TWF: 145.92 (292.8)
TWF wins at every ac (just about)
The "damage gap" increases as the chance to hit increases. Thus a fighter with buffs and a better item selection (who can reasonably expect to have attacks in the +45 range) does significantly better as a TWF fighter. As would a fighter with haste.
Majere
Majere, you're a funny guy. I've been messing around with some revised and 3.5 converted character builds, and did some rough (no criticals) damage per round comparisons. The lowest AC I bothered with for level 20 guys was 35.
Against AC 35, the damage from fully equiped characters piles up so fast that the only way for those critters (or wizards) to live is to have significant other defenses (miss chance, high DR, etc) or to avoid recieving full attacks like the plague. Looking at monsters with CR around 20, I generally see at least 35, usually with magic effects to boost that AC. Also, since most of the monsters at that level are intelligent, we can probably assume that some of that standard items treasure might be going to some defense. Potions are especially good for NPCs and monsters. Of course, the DM can also treat low AC enemies as one shot attackers.
In other words, the greatsword character has an advantage in damage when the AC-att difference is as small as 3 (5 for the two weapon). When you consider the stratospheric ACs attainable by fully buffed or equiped demons, dragons, defensive fighters, and the like, even with +45 attack bonuses the AC ranges will often favor one big weapon.
Of course, one reason your double weapon guy is winning at almost level is because he's spent at least 50k more, and is using his feats. Given your strategy of low base dex plus magic item, we're actually looking at an 86k gap. The various bonus abilities aren't all that situational - holy applies probably at least 80% of the time. Sometimes, they're required to beat DR. Yes, you could have a cleric cast GMW on your weapon(s). However, since your talking about doing damage, if you can reliably have GMW, you won't have a +1 weapon at level 20. You'll have a +1 weapon with at least +6 in different abilities that then gets the GMW. Furthermore, the additional spell required to buff up the 2 weapon guy can't be neglected. When playing a cleric, I usually gave the GMWs to the single weapon guys, since it affects 100% of their attacks, and looked for buffs that would affect all the TWFs attacks - mainly bull's strength. Even if the cleric is willing to throw 2 spells your way, nothing says that the Greatsword user can't benefit from a second spell. Many of the more situational weapon abilities are available from spells, for example, disruption and certain bane types. Or the cleric saves the spell and then casts Divine Power later on, so you have two good combatants instead of one.
Then there's the feats that the greatsword character isn't using. He's not using 4 feats compared to the two weapon character (neither character is using all his feats). You might say that the two weapon character has an advantage here simply because he can bring more feats to bear. In a core rules only game, this is indeed a problem for the two hander. Cleave is good, especially at lower levels. Iron Will is almost a must. Imp Sunder works well with the 2 hander style - doing damage in one big lump defeats hardness. Expertise can be useful. You can also go off the beaten path and pick up Dodge, Mobility, and Spring Attack. Although limiting one's armor, the ability to deny the enemy full attacks will probably save a bit more damage. Since 2 handed weapons do the most damage on a single attack, they can the most by restricting the battle to single attacks rather than full attacks. Look at non-core options, and the greatsword's effectiveness further increases. The 4 feat difference could easily be used to pick up Combat Brute, Shock Trooper and their prereqs. The power attack advantages offered by those feats work best with greatswords and the like - since the second part of the double weapon is considered light, power attack isn't as effective with two weapon. Or something horribly broken like Karmic Strike could be employed - damage on a single hit is of paramount importance when you do lots of damage from AoOs.
