Tri-Ominos

Officially Tri-Ominos (Pressman Toy)

TRIANGULAR DOMINO variant using 56 EQUILATERAL-TRIANGLE tiles (each with 3 numbers 0-5 at corners). 2-6 players build TRIANGULAR TILE NETWORK matching corner-numbers; score = SUM of played tile's numbers + BONUS for closing HEX (6 tiles sharing center point). Invented 1965 by ALLAN COWDERAY (USA); popularized by PRESSMAN TOY 1970s+. Regular Tri-Ominos deck goes 0-0-0 through 5-5-5. Rules simple, appeals to strategy-lite domino fans + kids/families.

~30 min🌤indoor

Quick facts

Category

Tile Games

Type

Individual

Players

2–6

Duration

~30 min

Where played

indoor

Country of origin

🇺🇸 United States

Estimated origin

Invented 1965 by Allan Cowderay (USA); commercialized 1968 by Pressman Toy Corporation (New York); 10M+ sets sold globally; deluxe travel + Tri-Ominos 200 variants (goes up to 9-9-9 with 220 tiles).

Olympic

No

Popularity

regional

How it works

Objective

Score MOST POINTS by placing tiles + closing HEXES + racing to empty hand.

Rules

Basic rules

  • SETUP: Shuffle 56 tiles FACE-DOWN; DEAL 9 (2p), 7 (3-4p), or 6 (5-6p) to each player; rest = BONEYARD (draw pile)

    Signature deal + boneyard.

  • FIRST TURN: player with HIGHEST 3-of-a-kind (5-5-5 if held) plays it face-up to start network + scores its 15 points (5+5+5)

    Signature high-triple opening.

  • TURN: play 1 TILE onto network — tile's TWO NUMBERED CORNERS must MATCH the two exposed numbers where placed

    Signature 2-corner match rule.

  • SCORE: player scores SUM OF TILE'S 3 NUMBERS (e.g., 2-3-5 = 10 pts) + BONUSES for completing hexes/bridges (25-50 pts)

    Signature sum-plus-bonus scoring.

  • HEX BONUS: complete a 6-tile HEX (all sharing central point) = 50-POINT BONUS

    Signature 50-point hex bonus.

  • BRIDGE BONUS: play tile connecting two previously-separate networks = 40-POINT BONUS

    Signature 40-point bridge bonus.

  • DRAW IF STUCK: if can't play, draw from BONEYARD; must play if drawn tile fits; if empty, pass turn

    Signature draw-if-stuck rule.

  • END ROUND: FIRST player to play LAST TILE bonuses +25 pts + OPPONENTS'S remaining tiles subtracted

    Signature first-empty +25 bonus.

  • GAME: play to 400 POINTS (default); can also play best-of-3 rounds

    Signature 400-point game.

Scoring

Tile value + hex/bridge bonuses; first-empty +25; opponents' remaining tiles as penalty.

Win condition · First to 400 points.

Equipment

  • TRI-OMINOS SET: 56 EQUILATERAL TRIANGLE TILES (with numbers 0-5 at each corner)

    Signature 56-tile triangular set.

  • SCORE PAD + PEN

    Standard score-keeping.

  • OPTIONAL: DELUXE 200-TILE SET (numbers up to 9-9-9)

    Standard deluxe variant.

Terminology

Corner
One of 3 numbered corners of triangular tile.
Boneyard
Draw pile of unused tiles.
Hex
6-tile hexagonal cluster sharing central point — 50 pt bonus.
Bridge
Tile connecting two separate networks — 40 pt bonus.
Match
Tile's 2 corners must match exposed numbers on network.
5-5-5
Highest 3-of-a-kind tile — starts round + 15 pts.
Pressman Toy
US commercial publisher — makes Tri-Ominos + other Pressman-brand tile games.

Major competitions

  • No formal championships; casual family + travel game

    n/a · USA + international · since 1965

Where it is played

Governing bodies

  • Pressman Toy Corporation (publisher)

    Founded 1922 · New York, NY, USA

  • Goliath (parent company)

    Founded 1980 · Culemborg, Netherlands

Famous names & records

Famous athletes

  • No professional scene; casual family + travel game

Sources & provenance

Last verified 2026-08-28.verified