1) Liability/medical - Check your home owners policy if you are covered already. If not, what do you do if someone slips off your camper's steps and is permanently disabled?
2) Collision - If you back into a tree while you are hooked up to your TV, you are covered PROVIDED (for example) you have collision on your truck's policy AND the policy limit amount is sufficient to cover BOTH vehicles (IF both vehicles are involved). HOWEVER, if you disconnect your camper, and it rolls back into a tree; no coverage. Collision also pays if someone runs into your camper while you are stopped at a light and someone runs into you who does NOT have enough (or no) insurance. Trying to sue the person who has no insurance or assets is an exercise in futility.
3) Comprehensive - Most auto policies require collision to even GET comprehensive. Comprehensive covers fire, theft, water damage, tree falls on camper at campground (and other "acts of god" - like bull elk jumping through your window), wind damage (tornado), or just about anything that does not fit in collision.
4) Towing - Getting your camper towed if your truck beaks down can be a REAL eyeopener. In the case of a 5th wheel, BOTH vehicles are towed together if the camper is the problem. Towing on BOTH allows the fee to be split between the vehicles.
So, I say camper insurance is worth every penny.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW