D&D 3.5 Double Weapons - Enhanced

Players Handbook; SRD Link

All Double Weapon Types: Double weapons have a slight change to them in an attempt to make them more attractive to players. The primary hand damage will be 1.5 Str bonus and the off hand is just Str bonus, and if you have Two-Weapon Fighting you would be at -2 primary and -4 off hand. The off-hand is no longer considered light for purposes of Two-Weapon Fighting. For more info please see Exotic Weapon Proficiency Heavy Double