Here is some suggested wording for CASEMATES, to address Go0gleplex's feedback (which I agree with).  May not be perfect, but I think it make the function more clear.

3) CASEMATES: This trait indicates a starship whose weapons are heavily armored or otherwise protected against damage.  When rolling damage for a ship with Casemates, a roll of 3 will only cause Hull damage (not Weapon damage). Weapon damage is still taken as normal on a roll of 4.