How to play Pips — a free daily domino logic puzzle

Pips takes the humble domino — a tile with two ends, each showing anywhere from zero to six dots, or pips — and turns it into a deduction puzzle. A board of connected cells is carved into coloured regions, and each region carries a small rule in its corner. Your job is to place every domino from the tray so the whole board is covered and every rule comes out true. There is a new board every day, shared by everyone, and when the daily puzzle is done an unlimited practice mode generates fresh, solvable boards whenever you want more.

Three things set the tone. First, it is free — there is no paywall and no premium upsell. Second, it asks for no account: your streak and statistics live in your own browser, so you can start the moment the page loads without handing over an email address. Third, the interface is quiet — type-set dominoes, real drawn pip faces rather than emoji, and a plain-text share you can paste to friends without a single picture-character in it.

It is also built to be read by everyone. Every region badge shows a shape as well as a colour — a check when the rule is satisfied, a cross when it is broken — and a running text status tells you how many dominoes are placed and how many regions are met, so nothing depends on colour alone. The board renders before any script runs, so it works on a slow connection and is fully keyboard-operable.

Because there is no timer pressure built into the rules, Pips rewards a careful read of each region over raw speed. Solve the day’s board and your streak ticks up; come back tomorrow to keep it alive. And when you finish, a built-in solver is on hand: a Hint drops one correct domino, and Show solution reveals the whole tiling — both powered by the same exhaustive checker that proves each board has a single answer.

The goal is to tile the entire board with the dominoes in the tray. Each domino lies flat across two touching cells — up-and-down or side-to-side — and every cell must be covered by exactly one domino half. No cell is left empty, and no two dominoes overlap. In the language of logic puzzles, you are looking for an exact cover of the board.

What makes it a puzzle rather than a jigsaw is the set of coloured regions. Each region groups a handful of cells and prints a rule in its corner that the pips covering those cells must obey. The rules come in five flavours:

A region may also be left blank, with no symbol at all. A blank region carries no constraint — any pips are welcome there — so it acts as breathing room where you can park an awkward domino.

The twist that gives Pips its bite is that a single domino often straddles the border between two regions. When it does, one end lands in each region, so that one piece has to help satisfy both rules at the same time. The regions are just about the rules; the dominoes do not have to match their colours. Getting a domino to answer to a sum on one side and, say, an equals rule on the other is exactly where the deduction lives.

Deduction in Pips almost always starts the same way: you find the region that can only be filled one way and work outward from it. Here is a small four-cell demonstration board to show the shape of that reasoning. It has two regions of two cells each, and a tray of just two dominoes — the zero–three and the four–four (a double four).

Start with the most constrained region — the amber one, marked equals. Its two cells must show the same pip value. If a single domino covers both of them, that domino has to be a double, because only a double shows the same number on both ends. The four–four is the only double in the tray, so it is forced into the amber region. That is one placement locked in with no guessing at all.

Now the elimination does the rest. The four–four is spent, which leaves only the zero–three for the sky region — and conveniently, zero plus three totals exactly three, which is what the sum rule demands. The four–four never could have filled the sky region anyway: four plus four is eight, nowhere near a target of three. So the last domino drops into place, the board is fully covered, and both region badges flip to a check. One forced double, one forced sum, and the puzzle falls.

Real daily boards are larger and their dominoes cross region borders, so the chains run longer — but the engine is always the same: pin the region that admits only one option, place the domino it forces, then let that placement narrow everything it touches.

The New York Times popularised this domino logic format, and we are happy to say so plainly: Pips on duplixo is the same kind of puzzle. It is an independent clone, built on our own original code — the board renderer, the region validator and the backtracking solver are all ours — and it is not a copy of anyone’s puzzle data. What we have added is a free, unlimited version with a solver, a proper archive and a colour-blind-safe board. The table below lays out the practical differences.

The gap that matters most is what happens after you solve. The Times keeps no archive of past Pips boards, so once a day rolls over the puzzle is gone. duplixo keeps a dated archive of every board and, on top of it, an unlimited practice generator — so you can replay a board you missed or spin up a brand-new one whenever you like.