If you have paid off your car, comprehensive coverage is optional. It may be a good idea to find out the Kelley Blue Book value of your vehicle. Would you be able to pay that amount to repair or replace your vehicle if it were stolen or damaged in an accident? If you can't afford to pay much out of pocket, then buying optional coverages, like comprehensive coverage and collision coverage, may be a smart investment.
Policies typically use vague language when referring to acts of terrorism, but they are generally insured by the comprehensive portion of your policy. For example, if there is an act of terror and you need to make a claim on your car, that can only be made if you have comprehensive coverage. Since some circumstances are out of our control, comprehensive insurance is certainly important to have in your policy.
Actual cash value equals the purchase price of your car minus depreciation and your deductible. So comprehensive coverage will pay an amount up to the actual cash value of your car to either repair or (in the case of a total loss) replace it. If the cost of repairs exceeds your car's ACV, your car insurance company will declare it a total loss and pay the sum of the car's ACV to help you replace it — unless you opt to retain salvage (i.e., keep the totaled car), in which case the salvage value will also be deducted from your payout.
Comprehensive insurance is commonly confused with collision. They both insure your car but cover different events. Collision covers car accidents, and comprehensive covers events out of your control. Think of it like this: Collision is colliding with something else (other than animals). Comprehensive is basically all other events. Accidents with animals are covered by comprehensive (and not collision) because these accidents are considered out of your control.