How are armor spikes used in a grapple?

Question

Armor spikes' page says:

Armor spikes deal extra piercing damage (see “spiked armor” on Table: Weapons) on a successful grapple attack. The spikes count as a martial weapon.

Which seems to imply that it functions similarly to Constrict; extra damage on a successful grapple check.

But Grapple says:

You can inflict damage to your target equal to your unarmed strike, a natural attack, or an attack made with armor spikes or a light or one-handed weapon.

Which seems to imply that they are just another option to use in a "Damage" action from a successful check.

Which is the correct usage, and if it's the former, would it still apply the grappler's strength mod to damage?

Answer 1

I don't see a contradiction between the two quoted rules sections.

From the first we are told armor spikes deal extra damage, 1d6 for medium creatures. They count as a martial weapon so if you're not proficient with them you take a -4 to attack on the grapple if you want to use them. So other than having to state you intend to use them in the upcoming grapple, which would only be necessary if nonproficient, to allow the attack roll can be calculated correctly, its a normal grapple.

From the second we see all the other damage inflicting options would allow strength bonuses to be applied, and it is baked into the CMB used to start a grapple, so there is no reason to believe armor spikes would not have a strength adjustment on damage they deal. 1d6+str

The only thing I'd add would be that, even if you did need to say you were using the armor spikes up front due to a nonproficiency, you could still choose to do any of the other types of damage, or no damage at all.