A universal tube launched munitions system has a launcher base having an array of a plurality of initiator stations, first and second cassettes each having a mounting facility operable for releasable connection to the launcher base, each of the cassettes having a plurality of barrels, the barrels of the first cassette been axially registered with the first quantity of the initiator stations, and the barrels of the second cassette been axially registered with a different second quantity of the initiator stations. The barrels of the first cassette may be axially registered with all of the initiator stations. The barrels of the second cassette may be axially registered with a subset of the initiator stations the barrels of the first cassette are axially registered with. The barrels of the first cassette may have a different diameter than the barrels of the second cassette.