What is the typical insurance treatment of losses caused by the insured's intentional acts?

Property and casualty insurance is designed to cover fortuitous losses — those that are accidental, sudden, and unexpected from the insured's standpoint. Losses the insured causes intentionally or fraudulently (such as arson by the owner) are generally excluded, because covering them would violate the nature of insurance and create a moral hazard, effectively rewarding wrongdoing. This is why policies contain exclusions for intentional acts and provisions voiding coverage for fraud or material misrepresentation. The requirement that a loss be fortuitous is fundamental. Understanding that intentional acts are excluded — insurance covers accidents, not deliberate harm — is standard perils-and-exclusions content.