Every cell on a Domino Logic board shows a face value, but the domino lines are missing. Your job is to draw horizontal or vertical dominoes across neighboring cells until each unordered pair in the set appears exactly once. The puzzle is pure placement logic: no arithmetic, no guessing about hidden clues, because every face is already printed. Publishers call the same mechanic Domino Logic; puzzle magazines and libraries often label it Dominosa. Puzzle Maker Pro – Domino Logic generates these grids for print and digital books.
This page is a solving guide for readers and for anyone who prints books or worksheets. It covers the rules, how board size relates to the domino set, techniques from first moves through harder elimination, and a fully worked small board. Book layout, batch settings, and export choices are intentionally light here; those live in the paired Domino Logic puzzle generators guide for publishers.
What you are looking at
A finished puzzle is a rectangle of numbers (or letters, colors, or images that stand in for numbers). A domino always covers two cells that share a side, either across or down. Each domino represents one unordered pair of face values: [3|5] is the same tile as [5|3]. Doubles such as [2|2] count as their own pair.
The generator hides a complete double-n set. Faces run 0 through n (not 1 through n). For native set size n = 5, faces are 0–5, there are 21 dominoes, and the grid is 6 rows × 7 columns — seven wide, six tall. That is the size in the figure below, a typical Basic board from Domino Logic.
On the puzzle page, only the faces print. On the solution page, heavy lines show how the dominoes partition the grid (see the solution image in the walkthrough section). Optional Display Tiles Stack in the software can also print a legend of the full set beside the board; solvers can treat that chart like a checklist.
If you need a slower rules pass with magazine-style wording, understanding Domino Logic on the site stays available. This guide uses the engine’s 0-based faces so your markings match Puzzle Maker Pro output.
Rules in one pass
- Cover the grid. Every cell belongs to exactly one domino. Dominoes cannot overlap or leave holes.
- Use the whole set. Each unordered pair of face values from the double-n set appears on exactly one domino. Once you place
[1|4], no other domino may use that pair. - Orthogonal only. Dominoes span two cells that touch across or down, never diagonally.
- Respect uniqueness when promised. Boards generated at Trivial, Basic, Hard, or Extreme are built to have one tiling. Ambiguous boards deliberately may admit more than one valid tiling; treat them as practice for logic, not as keyed exam pages.
Faces can be printed as Arabic numbers, Roman numerals, letters, color shapes, or images. The solving task is unchanged: match identities, not numeric order. A red square paired with a blue circle is still one specific tile in the set.
The checklist every solver needs
Because pairs cannot repeat, experienced solvers keep a domino chart — a small table of every pair in the set. Cross off a row when you are sure that tile is placed. Without that chart, it is easy to “spend” [2|3] twice on two different parts of the board.
For a double-5 set (faces 0–5), the chart has 21 rows: six doubles plus fifteen mixed pairs. On a double-6 set (faces 0–6, 28 dominoes, 7×8 grid), you need all 28. When you print for students, include the chart on the instruction page or turn on Display Tiles Stack so the set is visible beside the grid.
Beginner tactics
Anchor the doubles. A double can only live where two identical faces touch. Scan for [0|0], [1|1], and so on. On many boards, doubles are the first dominoes you can draw with confidence.
Claim unique adjacent pairs. Sometimes only one copy of a pair appears on the entire board as two touching cells. If you see a single horizontal or vertical [4|1] and no other 4 touches 1 anywhere else, that domino is settled.
Work from corners and edges. A cell on the border has fewer neighbors. If a corner shows 0, only two directions exist; often only one partner value appears next to it, which limits which domino can use that corner.
Do not confuse “similar” with “the same tile.” Two separate [3|5] placements are illegal even if other numbers nearby look alike. The chart is what keeps you honest.
Intermediate tactics
Count dominoes, not just printed digits. On a double-5 board, the face 5 appears on seven cells: six different dominoes use a five ([5|5] contributes two fives, and [5|0] through [5|4] contribute one each). Cross dominoes off your chart when they are placed. When a printed 5 still has only one unmatched neighbor that can complete a remaining tile, that domino is forced.
Eliminate bridges. If joining cells A and B as [2|3] would strand a third cell with no legal partner, that join is impossible even though the pair exists somewhere on the chart.
Use the solution shape, not arithmetic. Domino Logic never asks you to add face values. When difficulty rises, the challenge is global consistency: placing one domino changes which pairs remain available three rows away.
Expert habits on full-size boards
On a 6×7 or 7×8 grid, brute-force search fails quickly. Strong solvers alternate between local forced moves (doubles, unique pairs, border cells) and constraint propagation: after each placement, update which pairs are still unused and re-scan for cells whose neighbor set now contains only one legal partner.
When you print Hard or Extreme boards from Domino Logic, expect fewer immediate doubles and more long chains where each placement unlocks the next. If you stall, re-scan for a face value that appears only once still unmatched — that cell often has a single legal neighbor left.
Avoid treating Ambiguous boards as keyed homework unless you also print all valid solutions. For competition-style books, stay on Trivial through Extreme.
Worked example: a 4×3 “double-2” board
The boards below are Trivial difficulty with native set size n = 2 (faces 0–2, six dominoes, grid 4 columns × 3 rows). Rows are numbered from the top, columns from the left.
Puzzle grid
| c1 | c2 | c3 | c4 | |
|---|---|---|---|---|
| r1 | 0 | 1 | 2 | 0 |
| r2 | 0 | 2 | 1 | 1 |
| r3 | 1 | 0 | 2 | 2 |
Step 1 — Place the [0|0] double. The only adjacent zeros are r1c1 and r2c1. Mark that vertical domino and cross [0|0] off the chart.
Step 2 — Place the [2|2] double. r3c3 and r3c4 are the only touching twos. Cross [2|2] off.
Step 3 — Place the [1|1] double. r2c3 and r2c4 are the only two ones that touch. Cross [1|1] off.
Step 4 — Place [2|0]. The corner r1c4 (0) has only two neighbors: r1c3 and r2c4. r2c4 is already used by [1|1], so r1c4 must pair with r1c3 (2) as the horizontal [2|0] domino.
Step 5 — Place [1|2]. r1c2 (1) and r2c2 (2) are now the only free cells that can complete [1|2].
Step 6 — Finish [1|0]. r3c1 and r3c2 are the last open cells; they form [1|0].
Every pair from the double-2 set is used once. The solution image shows the same partition with domino borders drawn.
Try the six steps on the puzzle image before peeking at the solution. The logic is the same on a 6×7 sheet; only the chart grows.
A harder board at a glance
The featured 6×7 puzzle at the top of this page is a Basic board. Solving it by hand belongs in a dedicated puzzle session, but the opening is typical of medium difficulty: locate doubles and unique pairs along the top row, then chase a single high-value face (here, several 5s) to see which neighbors are still available. The solution image draws 21 domino outlines — one per tile in the double-5 set.
If you publish that page, pair it with the unsolved grid on the facing page so Look Inside previews show the real challenge.
Quick notes for publishers
Domino Logic exports puzzle and solution images (JPG, PNG, and PDF through the book tools). Trivial through Extreme are safe for answer keys; flag Ambiguous separately if you include it. Every paid Puzzle Maker Pro edition lets you sell the finished books, worksheets, and packs you make to your own readers and customers; the higher Domino Logic edition adds the right to sell or supply the generated puzzles to other publishers and sellers.
Keep one domino size per interior unless the title promises a mix. A double-5 book should not hide a double-6 chapter without relabeling the set size.
Other puzzles you might like
If Domino Logic clicks with your audience, logic puzzle books for KDP maps where it sits beside region dividers, path puzzles, and placement games. For Etsy-sized packs of deduction printables, see Etsy logic puzzle printables. Ready to generate batches, tune difficulty, or wire a puzzle book export? Continue with Domino Logic puzzle generators — the publisher-facing companion to this solving guide.