Triangular Dominoes

Triangular Dominoes was granted a patent in 1885 and is an early instance of the concept of Dominoes applied to triangular pieces. Along the side of each piece is a number from zero to five, expressed with a blank or a number of dots. (Later games like Tri-Ominos would place the numbers on the corners of the pieces.) Also, in the center of each piece is a digit representing the sum of all the piece's sides. The smallest number of unique combinations of pieces results in a fifty-six piece set, plus a special fifty-seventh piece marked with a star and called “the boss.”

The game's inventor, Franklin H. Richards, included in his patent application several games to be played, involving matching the sides of the pieces or matching by the central (total) digit, and trying to outscore the opponent to win. The boss piece may or may not be used in these games as a kind of joker, matching up to any number. Also included with the patent is a description of a smaller set of triangular dominoes, with only the numbers zero through four, resulting in a total of 35 pieces, including the boss.