A schooner is a type of sailing vessel defined by its rig: fore-and-aft rigged on all of two or more masts and, in the case of a two-masted schooner, the foremast generally being shorter than the mainmast. A common variant, the topsail schooner also has a square topsail on the foremast, to which may be added a topgallant. Differing definitions leave uncertain whether the addition of a fore course would make such a vessel a brigantine. Many schooners are gaff-rigged, but other examples include Bermuda rig and the staysail schooner.