Recreational vehicles do more than just carry you from one place to another; they transport you with an eye toward maximum fun and/or comfort along the way. Just because some of these vehicles are associated with playtime, that doesn't mean they don't need the same insurance protection as any other piece of expensive property you own. In fact, they may need more insurance since they also create a potential for liabilities.
Your recreational vehicle is, just like an automobile, a moving vehicle that can cause bodily injury and property damage to others. In order to help pay for any damage you inadvertently inflict, you should secure liability insurance. This policy can also help cover the cost of environmental cleanup after an accident that causes the spillage of a toxic chemical or other pollutant.
Liability coverage will have limits that work on both a per-incident and per-policy basis. They may also have a deductible that requires an out-of-pocket contribution for each incident or year.