What is the difference between a 'named perils' policy and an 'open perils' (all-risk) policy?

A named perils policy covers a loss only if it is caused by a peril that is specifically listed (named) in the policy — placing the burden on the insured to show the loss came from a covered peril. An open perils (also called all-risk or special form) policy covers loss from any cause except those specifically excluded — placing the burden on the insurer to show an exclusion applies. Open perils coverage is broader and generally more desirable, while named perils is more limited. For example, the HO-3 homeowners form typically provides open perils on the dwelling but named perils on personal property. This distinction is key perils-and-exclusions content.