From the Libertarian Platform:

The only legitimate use of force is in defense of individual rights—life, liberty, and justly acquired property—against aggression. This right inheres in the individual, who may agree to be aided by any other individual or group. We affirm the individual right recognized by the Second Amendment to keep and bear arms, and oppose the prosecution of individuals for exercising their rights of self-defense. Private property owners should be free to establish their own conditions regarding the presence of personal defense weapons on their own property. We oppose all laws at any level of government restricting, registering, or monitoring the ownership, manufacture, or transfer of firearms or ammunition.