A naturally occuring crystaline material that blocks the Force. It is very rare. The Force can not sense through it or affect it directly.*

If a lightsaber comes into contact with cortosis, the power regulator will burn out. The lightsaber can not be activated until it has been repaired. Repairing this damage requires a new power regulator and a Difficult 15 Lightsaber Repair Check. A lightsaber without a power cell (see Conduit) will not require repair, but all Force Powers will be disrupted at contact.

Cortosis can be indentified (Geology?), mined (Mining?), and processed (Materials Science?) in small quantities. Alternately, Sith Alchemy can be used to create de novo cortosis.

Cortosis can be worked into weapons, armor, or stuctures to block Force use and lightsaber attacks. Materials laced with cortosis are more fragile than normal, but are impervious to lightsaber damage.

*[This is a non-canonical function of cortosis unique to our game universe.]