Dual-wield

Any character can use two weapons simultaneously. This is known as dual-wielding. This allows the character to gain additional attacks from a weapon in their off-hand at the cost of a penalty to his attack bonus. The penalties depend on a number of conditions.

Dual-wielding
If you wield a second weapon in your off hand, you can get one extra attack per round with that weapon.

You suffer a –6 penalty with your regular attack or attacks with your primary hand and a –10 penalty to the attack with your off hand when you fight this way.

You can reduce these penalties in two ways:
 * If your off-hand weapon is light, the penalties are reduced by 2 each. (An unarmed strike is always considered light.)
 * The two-weapon fighting feat lessens the primary hand penalty by 2, and the off-hand penalty by 6.

Additional off-hand attacks
Additional off-hand attacks may be gained by selecting further two weapon fighting feats.
 * Improved two-weapon fighting provides an additional attack with a -5 penalty AB, for a total of 2 off-hand attacks.
 * Greater two-weapon fighting provides an additional attack with a -10 penalty AB, for a total of 3 off-hand attacks.

Rangers
Rangers who choose the two-weapon fighting combat style gain Two weapon fighting (at 2nd level), improved two weapon fighting (at 6th level) and greater two weapon fighting (at 9th level). However these are only active if a ranger is wearing light or no armor.

Double weapons
You can use a double weapon to make an extra attack with the off-hand end of the weapon as if you were fighting with two weapons. The penalties apply as if the off-hand end of the weapon were a light weapon.

Thrown weapons
The same rules apply when you throw a weapon from each hand. Treat a dart or shuriken as a light weapon when used in this manner, and treat a bolas, javelin, net, or sling as a one-handed weapon.