upright=1.5|thumb|A game of Triominoes. Note how adjacent tiles are placed with matching corner values, and note the completed hexagon of six tiles (with corner values of 1 at the center). There are two uncompleted hexagons of five tiles, also with corner values of 1 at the center. One could be completed with the 1-1-3 tile, and the other cannot be completed, as the required tile would be 0-2-1, which does not exist.
Triominoes is a variant of dominoes using triangular tiles published in 1965. A popular version of this game is marketed as Tri-Ominos by the Pressman Toy Corp.
Composition
A triomino tile is in the shape of an equilateral triangle approximately on each side and approximately thick. Each point of the triangle has a number (most often from 0 to 5, as in the Pressman version), and each triomino has a unique combination of numbers, subject to the following restrictions:
- Any number is allowed to repeat in the combination. For example, 0-0-0 or 0-0-1 are possible combinations.
- When reading the numbers sequentially clockwise, starting with the lowest value, the numbers are not allowed to decrease. For example, 0-1-2 and 0-2-3 are possible, but 0-2-1 is not allowed.
Given these restrictions, with the six potential values (0–5) commonly seen, there are 56 unique combinations, and thus the standard triomino set has 56 tiles. Larger sets are possible; for example, including 6 as a possible end number would result in 84 tiles.
Tiles are most often made from plastic or resin that approximates the feel of stone or ivory, similar to most modern commercial domino sets. Numbers are recessed into the surface and painted black. Some "deluxe" sets include a raised, brass tack head in the center. This addition to the sets assists in mixing up or shuffling tiles, as the tack head reduces the surface area of the tile contacting the table, so tiles move more freely.
{|class="wikitable" style="font-size:85%;text-align:center;"
|+Triomino tiles (corner values 0–5)
! Triples
! colspan=6 | Doubles
! colspan=9 | Singles
|-
| frameless|upright=0.25
| rowspan=2 style="background:#ddd;" |
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25
| rowspan=4 colspan=9 style="background:#ddd;" |
|-
! 5-5-5
! 4-5-5 !! 3-5-5 !! 2-5-5 !! 1-5-5 !! 0-5-5
|-
| frameless|upright=0.25
| frameless|upright=0.25
| rowspan=2 style="background:#ddd;" |
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
|-
! 4-4-4
! 4-4-5
! 3-4-4 !! 2-4-4 !! 1-4-4 !! 0-4-4
|-
| frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| rowspan=2 style="background:#ddd;" |
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25
| frameless|upright=0.25
| rowspan=2 colspan=8 style="background:#ddd;" |
|-
! 3-3-3
! 3-3-5 !! 3-3-4
! 2-3-3 !! 1-3-3 !! 0-3-3
! 3-4-5
|-
| frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25
| rowspan=2 style="background:#ddd;" |
| frameless|upright=0.25
| frameless|upright=0.25
| frameless|upright=0.25
| rowspan=8 colspan=1 style="background:#ddd;" |
| frameless|upright=0.25 || frameless|upright=0.25
| rowspan=2 colspan=5 style="background:#ddd;" |
|-
! 2-2-2
! 2-2-5 !! 2-2-4 !! 2-2-3
! 1-2-2 !! 0-2-2
! 2-4-5
! 2-3-5 !! 2-3-4
|-
| frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| rowspan=2 style="background:#ddd;" |
| frameless|upright=0.25
| frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| rowspan=6 colspan=1 style="background:#ddd;" |
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25
| rowspan=4 colspan=1 style="background:#ddd;" |
|-
! 1-1-1
! 1-1-5 !! 1-1-4 !! 1-1-3 !! 1-1-2
! 0-1-1
! 1-4-5
! 1-3-5 !! 1-3-4
! 1-2-5 !! 1-2-4 !! 1-2-3
|-
| frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25
| rowspan=2 style="background:#ddd;" |
| frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25
|-
! 0-0-0
! 0-0-5 !! 0-0-4 !! 0-0-3 !! 0-0-2 !! 0-0-1
! 0-4-5
! 0-3-5 !! 0-3-4
! 0-2-5 !! 0-2-4 !! 0-2-3
|-
| colspan=8 rowspan=2 style="background:#ddd;" |
| colspan=2 rowspan=2 style="background:#ddd;" |
| frameless|upright=0.25 || frameless|upright=0.25
| frameless|upright=0.25 || frameless|upright=0.25
|-
! 0-1-5 !! 0-1-4 !! 0-1-3 !! 0-1-2
|}
Playing the game
Setup and initial move
At the start of the game, all of the tiles are placed face down and shuffled. Players randomly draw their starting pieces. The specific number depends upon the number of players: a two-player game uses nine pieces per player to start, three or four players use seven pieces, and five or six players use six pieces. The tiles after the draw are kept face-down for later use. In this case, the only triple tile held is the triple zero, which would otherwise be trumped by any other triple tile.
If no triple is held by any player, the player with the highest single tile value plays it and scores its value without the 10 point bonus. Tile values are computed by summing the three numbers. For example, the 2-4-5 tile is worth 2+4+5=11 points. A new app was launched in 2015, coinciding with Triominos' 50th anniversary.
Variants
Variants manufactured by Pressman have included "Quad-Ominos", with square-shaped tiles, and "Picture Tri-Ominos".
See also
- Triangular Dominoes, a similar game patented in 1885, with values marked on the sides rather than the corners.
- Trioker, a domino-like game invented by Marc Odier in 1969, also played with tiles shaped like equilateral triangles; the corner values range from zero to four.