soap game
n.— «The Newcomerstown Trojans closed out their pre-season grid activities on a winning note Saturday night, outscoring the West Lafayette Generals give touchdowns to one in the two clubs’ annual “soap game” on the winner’s field.» —“NCTown 11 Tops Injured Generals; TR Patriots Win” Coshocton Tribune (Ohio) Sept. 3, 1963. (source: Double-Tongued Dictionary)