Penal Code section 529, paragraph 3, by its own terms, is violated when one intentionally falsely personates another, and, in such assumed character, does any act that might cause the liability or benefit described. The trial court here failed to instruct the jury on specific intent, so the Court of Appeal reversed appellant’s conviction for second degree burglary, which had been predicated on the theory that he entered a Lucky store with the intent to commit false personation. The court rejected the notion that this construction could end the Halloween tradition of “trick or treating,” noting that appellant had failed to disclose any such prosecution. Moreover, the application of the mental state established in this opinion does not violate the ex post facto or due process clauses of the state and federal Constitutions because it is not an unforeseeable enlargement of criminal liability. Justices Brown and Kennard concurred.