Dungeons And Dragons Online: DDO News: Dual Wielding and Combat

A topic of much interest has sprung up on the official forums, and Xundau is there to talk a little bit about dual wielding and the DDO combat system:

Now, when you're wielding two weapons, your attack animations are obviously different, but the attack progression system is still the same. The difference, of course, is that you're wielding two weapons, so on some of your attacks, you'll get an off-hand attack on the monster. As you get better at two-weapon fighting (with feats like Improved Two-Weapon Fighting), you'll get the off-hand attack more often.

All of the other PnP rules for two-weapon fighting -- the to-hit penalties, the reduction in penalties if your off hand weapon is a light weapon, having only 1/2 of your Str bonus to damage in your off hand, etc. -- should apply in DDO.

There is plenty more to the post which you can read right here. He also comments briefly on blocking in the same thread in this post, and a few more answers here. Some interesting tidbits for sure.