<P> The traditional set of dominoes contains one unique piece for each possible combination of two ends with zero to six spots , and is known as a double - six set because the highest - value piece has six pips on each end ( the `` double six '' ) . The spots from one to six are generally arranged as they are on six - sided dice , but because blank ends having no spots are used , seven faces are possible , allowing 28 unique pieces in a double - six set . </P>
what dominoes are in a double six set
one unique piece for each possible combination of two ends with zero to six spots