If you get hit by a deer and only have liability coverage would your car be covered?

No. Liability coverage takes care of any costs or damage you may do to other people and property during the course of driving, including both bodily injury to others and property damage. Collision insurance covers damage to your car when your car hits or is hit by another object, while comprehensive insurance covers losses resulting from incidents other than collision - floods, damage caused by external forces, and so on.