Contack

Contack is a dominoes-like game for one to seven players which was patented by Parker Brothers and published in 1939.

It uses 36 equilateral triangle tiles; each side is assigned a different color and numerical value.

Play starts with the player holding the lowest-valued tile, computed by summing the three printed values for each side.

That player places the lowest-valued tile on the table as the opening move of the hand.

Scoring follows the same rules, including the matches that sum to a multiple of 5 on up to three edges.

This is followed by a repetitive draw-and-discard sequence: Another tile is drawn from the face-down pile.

If this tile cannot be played legally (matching color and either matching values or values sum to a multiple of five), it is placed, face-up, in a discard pile, and another tile is drawn from the face-down pile.

Opportunity Plays (matching two or three edges) are allowed and follow the same rules as the multiplayer version.

Australian Red Cross workers pack boxes for Christmas 1942, including Contack games
Valid move sequence:
  1. First player placed the 1-2-3 tile, shown on right.
  2. Second player placed the 9-2-8 tile, shown in middle, and scored 10 points for the summed value of the matched blue edges (1+9 is a multiple of 5).
  3. Third player placed the 9-5-8 tile, shown on left, scoring no points for matching values across the gold edges (8+8 is a match but not a multiple of 5).