House Rule.Drakon66 said:It could be done without being considered two handed fighting and you would have to have the intitive to do this. While holding your two handed sword in both hands you drop your shoulder into your opponent, body check stlye. At the same time thrusting the sword into him. Assuming your spiked armor has spikes on the upper arm/shoulder, you have just used both sword and armor do deliver damage. You shouldn't take any major penalty, however you would have to make a DEX role to see if you remained on your feet if the target goes down.
Drakon66 said:It could be done without being considered two handed fighting and you would have to have the intitive to do this. While holding your two handed sword in both hands you drop your shoulder into your opponent, body check stlye. At the same time thrusting the sword into him. Assuming your spiked armor has spikes on the upper arm/shoulder, you have just used both sword and armor do deliver damage. You shouldn't take any major penalty, however you would have to make a DEX role to see if you remained on your feet if the target goes down.
Armor spikes are a weapon distinct from your sword andSRD said:Armor Spikes: You can have spikes added to your armor, which allow you to deal extra piercing damage (see Table: Weapons) on a successful grapple attack. The spikes count as a martial weapon. If you are not proficient with them, you take a -4 penalty on grapple checks when you try to use them. You can also make a regular melee attack (or off-hand attack) with the spikes, and they count as a light weapon in this case. (You can’t also make an attack with armor spikes if you have already made an attack with another off-hand weapon, and vice versa.)
An enhancement bonus to a suit of armor does not improve the spikes’ effectiveness, but the spikes can be made into magic weapons in their own right.
So you take the TWF penalties and you must also make a full round attack in order to get the extra attack(s).SRD said:TWO-WEAPON FIGHTING
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.
Table: Two-Weapon Fighting Penalties summarizes the interaction of all these factors.