Omni Sudoku
Twenty-seven rules. One at a time. Sudoku that keeps teaching you something.
How it plays
Simple rules. Then more rules.
Start with plain old sudoku
Rows, columns, boxes. Eight levels that open easy and end expert, until you know the drill without thinking about it.
Learn one new rule per chapter
Each chapter opens with a card that explains its rule over a real board that obeys it. Kropki dots, killer cages, thermometers, a knight with a grievance. Twenty-seven in all.
Let them pile up
Later levels borrow a rule from an earlier chapter, so the journey accumulates instead of resetting every eight levels. By the end you read a board most people would need a legend for.
What's inside
216 levels, every one checked
Each level has exactly one solution, and the game proves it before it ships. A board that fools you is doing it fairly.
Three puzzles a day
A warm-up, a main event and a nightcap, seeded by the date so everyone gets the same boards. A week strip keeps count.
Hints that explain
A hint finds the next real deduction and tells you why, highlighting the cells that justify it. It only reveals a digit when nothing simple is left.
Mistakes, your way
Flag nothing, flag only what the board already contradicts, or check against the answer. The default never tells you anything you couldn't have worked out.
A level editor
Draw regions, dots, cages and lines. The editor tells you why a board isn't playable before you save it, then lets you play the one that is.
No clock, no banners
Take as long as you like. The only ad is a video you choose to watch for a hint or a reward; nothing plays between levels, nothing sits at the bottom of the screen.
A look at it
Paper, ink, and one teal that always means “yours”.
Journey
Twenty-seven rules. One at a time.
Chapter 2 · Kropki
Dots Between Friends 4 of 8
White dot: neighbours. Black dot: one is double the other. No dot: none of your business.
Daily
Sunday, 13 September
Main event · Thermometers
Hot and Cold
Digits climb from the bulb. Slow thermos let you catch your breath.
This week 14 of 21
Journey, Game and Daily. Light and dark themes, phone and tablet.
Twenty-seven rule sets
In the order the journey teaches them. Each one is a small step from the last.
- Plain Old Sudoku ClassicRows, columns, boxes. You know the drill.
- Dots Between Friends KropkiWhite dot: neighbours. Black dot: one is double the other. No dot: none of your business.
- Cages and Sums Killer cagesDotted cages add up to the little number in the corner. No repeats inside. Yes, we count.
- Hot and Cold ThermometersDigits climb from the bulb. Slow thermos let you catch your breath.
- A Knight's Grievance Anti-knightThe same digit a knight's move apart? Not on this board.
- Circles and Squares Odd / evenA circle holds an odd digit, a square an even one. Half of every marked cell is decided before you start.
- No Touching Anti-kingIdentical digits may not touch, diagonals included.
- Follow the Arrow Arrow sumsThe shaft adds up to the circle. A two-cell pill reads as a two-digit number.
- Nothing Next Door Non-consecutiveOrthogonal neighbours may not be consecutive. Next to a 5, no 4 and no 6.
- Reads Both Ways PalindromesThe line reads the same from either end.
- X Marks the Spot DiagonalsEach marked long diagonal holds every digit once. Two more rows to keep in your head.
- A Run, Shuffled RenbanConsecutive digits in any order, no repeats.
- Keep Your Distance WhispersNeighbours on a green line differ by at least five; on an orange one, by at least four.
- Mind the Gap Between linesEvery digit on the line falls strictly between the two circled ends.
- Same Seat, Different Bus Disjoint setsCells in the same position within their box all differ. Nine hidden sets, free of charge.
- High Ground FortressA shaded cell beats every unshaded neighbour it touches.
- Peaks and Valleys Min / maxArrows pointing in: lower than all four neighbours. Pointing out: higher.
- Big Neighbours Only 10+ linesNeighbouring digits on the line add to at least ten.
- Fair Shares Region sumsEach box the line crosses holds the same total along it.
- Four-Way Promises QuadruplesEvery digit in a corner circle turns up somewhere in the four cells around it.
- Silence Is a Clue Negative constraintAn edge with no dot promises the pair earned none. Every blank border is talking.
- One Digit Gets Ideas Anti-queenTwo copies of the marked digit may not share a diagonal.
- Every Line Agrees Magic squareIn the marked three by three, every row, column and diagonal shares a total.
- Between the Bread SandwichThe number in the margin totals the digits between the one and the nine.
- Down the Diagonal Little killerThe number outside totals the digits along the arrowed diagonal.
- The City View SkyscrapersEach digit is a building. The clue counts the ones you can see from that side.
- The First X X-sumsThe digit nearest the clue is X. The clue totals the first X digits.
Made for the slow lane
There's a timer, because people like to know. There is no clock you're racing, no lives to run out of, and no streak that shames you. Omni Sudoku is the paper puzzle with the parts paper couldn't do: it knows when you're right, it can tell you why a digit goes where it goes, and it works on a plane.
No sign-up. Your progress lives under an anonymous ID, and you can delete it whenever you want. What we keep, and why, is written in plain English.
Questions?
Stuck on a deduction, found a board you think is wrong, or need a hand with a purchase? We answer every message.