The only time you are required to have comp and collision coverage is if you have a loan on the vehicle and the bank requires full coverage. If the vehicle is paid for, you can carry liability-only if you wish. Collision covers your vehicle up to the blue book value (minus your deductible) for losses when you damage your car in an at-fault accident; or collide with something or even if your vehicle is hit while it is parked. Comprehensive covers everything that is not collision (i.e. theft, vandalism, hitting an animal in the road, hail or storm damage, flooding, and glass damage). Without those coverages, your insurance company will not cover any of those things. You can carry comprehensive and not collision, but cannot have collision without comprehensive.