One of the players in a Pathfinder game in which I am playing is arguing that characters should be able to get the additional attack for fighting with two weapons when attacking as a standard action, instead of a full-round action which is normally required to get additional attacks.
He argues that a character that dual wields a longsword and a shortsword with Two-Weapon Fighting and Improved Two-Weapon Fighting is a decent amount worse than a character that wields a greatsword and has Power Attack and Vital Strike.
Two weapon Joe
Point buy (ultimate min max 15 point buy)
Lvl 11 (so he can get most of the twf feat chain)
15 dex +2 race +2 levels = 19 (twf req)
Feats TWF, Improved TWF, Greater TWF (and some others but these are the important)
Weapons +2 Flaming Frost Longsword, +2 flaming Frost short sword (note this is almost all of the chars WBL)
BAB +11 +2 str +2 weapon = +15, so Standard action TWF +13 (-2 twf)/+13 (-2 twf)/+8 (additional -5 ImpTWF)/+3 (additional -10 Great TWF)
Assuming all hit (not very likely) dmg 1d8+2 str +2 weapon +1d6 fire, 1d6 frost, 1d6+1 str (+same modifiers) x3
Average dmg 4.5+10.5 +13 physical frost +14(4x3.5) +14(4x3.5) fire. Total:56 combined dmg/round
Two handed bob
16 str +2 race +2 level: total 20
and still has 5 points to spread around to other stats
Feats: power attack, Vital stike, Improved Vital stike
Weapon +2 Flaming frost Greatsword (still has tons of wealth left over for other stuff)
BAB: 11+5str+2weapon= +18 to hit. Standard attack vital Strike power attack: +15 (-3 pow attack).
Damage: 6d6+7 str +9 power attack +2 weapon +1d6 frost +1d6 fire
Average: 39 physical +3.5 fire +3.5 frost Total = 46 combined dmg
Total Average twf with standard: 56 combined
Total Average two weapon: 46 dmg.
Adding dr 5 and elemental resistance (not that uncommon at level 11)
TWF now deals: 8 damage
Two handed deals: 33 still and he has 32000gp extra to boost his combat effectiveness
I'm personally of the opinion that this restriction is in the game for some reason, especially since it survived the transition from 3.5 to Pathfinder, but I can't really wrap my head around the reason.
Ignoring the potential to slow down the game with additional attacks and looking strictly at balance, is two-weapon fighting only as a full-round action instead of as part as a standard attack action really balanced versus fighting with a two-handed weapon?
To clarify after reading AceCalhoon post. I was only calculating adding my house rule to allow the standard action additional TWF attacks. to allow a TWF to have mobility and keep up with damage roughly to a Two handed fighter. So that is why I didn't include the itterative attacks from BAB