After defining an N-pattern accent as a system where only N oppositions exist irrespective of the length of the accentual unit, I examine four characteristics cross-dialectically and argue that: (1) The accentual unit is a bunsetsu, which is found pandialectally; (2) Serialization basically holds true for the system, but not, when a noun has an accent kernel specified from the end of the word; (3) Both the compound accent rule to the effect that the accent of a compound inherits the accent of its first member, and accent pattern congruity in conjugation have many exceptions. Both depend on how the dialect underwent historical changes, at least in Mainland Japanese. Finally, the histories of two-pattern accent systems in Kyushu and three-pattern accents in Oki-no-shima are considered.
