Guides
Everything we have written about Chain — the rules, how to get better, how the puzzles are built, and how to play it with other people.
A short history of number puzzles in print
Magic squares, the crossword's arrival in 1913, Number Place becoming Sudoku, Countdown's numbers round, and how it all became one puzzle a day online.
7 min read
Chain FAQ
When the puzzle changes, what the site stores on your device, why the share is text, playing by keyboard, where the ads are, and how to report a wrong puzzle.
1 min read
Chain in a maths lesson
A five-minute Chain starter for a maths lesson: a minute-by-minute example, working backwards from a target, and using the archive for one shared board.
7 min read
Chain strategy — how we find the set
Last digits, exact division, working backwards from the target, and when swap digits is the answer. What we actually do when a puzzle will not give.
6 min read
How a Chain puzzle is made
A date becomes a seed, a seeded random walk becomes a puzzle, and an exhaustive solver discards it unless exactly one set of tiles solves it.
6 min read
How to play Chain
Reach the target from the start number in exactly the given number of moves, using each tile once. The rules, the controls, and four worked puzzles.
6 min read
Mental arithmetic that helps in Chain
Doubling, compensation, last-digit checks, divisibility without dividing, and what swap digits really does to a number — each one on a real Chain puzzle.
6 min read
Playing Chain with a child
When Chain starts to work with a child, how to play it out loud together rather than over their shoulder, and how to tell when today's puzzle is too hard.
8 min read
Playing Chain without a mouse
Every key the board listens for, what a screen reader hears on each move, how the theme toggle behaves, and the three places the keyboard support stops.
7 min read
Six mistakes that cost you tries in Chain
The habits that eat a beginner's first week — the biggest tile first, the miscounted move, the division that does not divide — and the puzzles they go wrong on.
6 min read
What a Chain streak is, and how to keep one
How the streak is counted here, where it is stored, how to anchor the puzzle to a thing you already do, and what to do when the streak stops being fun.
8 min read
What easy, medium and hard mean here
Difficulty follows the weekday, the move budget follows from that, and a score computed from the solved puzzle keeps every day typical for its length.
6 min read
Why Chain has no order of operations
Chain applies each tile to a running value, so there is no BODMAS — only the order you choose. Where ×2 then +5 and +5 then ×2 come apart, and how to spot it.
7 min read
Why one puzzle a day and not an endless supply
One board a day ends the session for you, everyone gets the same one, and it costs a few minutes. What we will not claim is that it makes you sharper.
7 min read
Wordle, Nerdle, Connections, and where Chain fits
An honest comparison of the daily puzzle formats — what each one asks of you, how long it takes, and which parts of them Chain does not do as well.
6 min read