Fair puzzles
Most puzzle sites ask you to take the quality of a board on trust. We would rather not ask. Every Griddle puzzle has to clear the same two tests before anyone sees it - one answer, and an answer you can reason your way to - and whatever clears them is then graded on how hard that reasoning actually was. A board that fails a test is not nudged until it scrapes through. It is thrown away.
- Boards published and verified
- 7,041
- That need a guess
- 0
- Named deduction techniques
- 17
- Games
- 3
That is 3,291 Daily boards, 3,000 for the endless mode and 750 across the countdown ladders. Every one of them has been proved to have exactly one answer, and proved separately to be reachable using only the 17 techniques listed below - no trial and error at any point. The full suite is re-run against the entire corpus before a release, so these are not one-off checks from whenever a board was made.
What every Griddle board goes through before it is published
- Uniqueness. Every Griddle board is put through a constraint solver that walks the entire solution space and counts the answers. There has to be exactly one. This is the full search, not a sample of it, and a board that comes back with none or with two is thrown out rather than nudged into shape.
- No guessing. A second solver then starts the same board again from scratch, this time allowed nothing but the named deduction techniques listed further down. If it gets stuck and has to start searching, the board is either binned or bumped up a tier. If the only way through a puzzle is trial and error, we do not publish it.
- Grading. The difficulty is read off that second solve. It comes from the hardest technique the solver needed, weighted by how often it had to reach for it and scaled to the size of the board. The Daily calendar then runs easy on Monday up to hardest on Sunday, and every build checks the ramp is still intact.
Every board carries its own proof
A Griddle puzzle does not simply arrive claiming to be fair. Each one ships with the record of how it was checked: which version of the solver cleared it, a hash covering the board and its answer, how much of the search the proof had to cover, and the exact techniques needed to solve it, in the order they were needed. Every claim on this page can therefore be checked against the board it is made about.
Griddle does not ship the answers to your browser
Solutions are not shipped. When you finish a grid, your device hashes what you have drawn and compares it to a salted hash that came with the puzzle. Hints work the same way round: the technique solver runs on your device, on your current position, and works out the next deduction from there. Digging an answer out of the files would mean solving the puzzle first, which is also how you win it. That is as far as we take it. Someone determined can always cheat themselves, and there is no anti-cheat here beyond this.
Every technique we use
Here are the full ladders. Nothing outside these lists is ever used to grade a board, and each technique gets a worked example in the game’s strategy guide.
Sentinels
| Rank | Technique | What it does |
|---|---|---|
| 0 | Last cell in a row | Every row holds exactly one sentinel. When a row has only one cell left that is not crossed out, that cell must be the sentinel. |
| 0 | Last cell in a column | Every column holds exactly one sentinel. When only one cell in a column survives, place the sentinel there. |
| 0 | Last cell in a region | Every coloured region holds exactly one sentinel. A region down to a single open cell is solved. |
| 1 | Region locked to a line | If every open cell of a region sits in one row, that region’s sentinel is somewhere in that row - so no other cell in the row can hold one. Cross the rest of the row out. |
| 1 | Line locked to a region | The mirror image: if every open cell of a row lies inside a single region, that region’s sentinel is that row’s sentinel, so the region’s cells outside the row can be crossed out. |
| 2 | Neighbour squeeze | Sentinels never touch, even diagonally. When a row’s candidates are packed into a narrow band, any cell in the row above or below that would touch every one of those candidates can be crossed out. |
| 3 | Locked tuple | If two or three rows have their candidates confined to exactly that many columns, those columns are spoken for. Every other row can be cleared of them. |
Eclipse
| Rank | Technique | What it does |
|---|---|---|
| 0 | Break up a pair | Two identical symbols side by side cannot become three. Both cells flanking the pair take the other symbol. |
| 0 | Fill a gap | A gap between two identical symbols must hold the other symbol - otherwise you would have three in a row. |
| 0 | Follow a marker | An “=” marker copies its neighbour’s symbol; a “×” marker takes the opposite. One known side settles the other. |
| 1 | Line is full | Each row and column holds exactly half suns and half moons. Once one symbol has filled its half, every remaining cell in that line is the other symbol. |
| 2 | Only one way to finish the line | Work out every legal way the line could be completed. Any cell that reads the same in all of them is settled, even if no single simple rule proves it. |
| 3 | Assume and refute | Suppose a cell is a sun and follow the simple rules. If that leads to an impossible board, the cell must be a moon. You never keep the guess - you only ever rule one out. |
Circuit
| Rank | Technique | What it does |
|---|---|---|
| 0 | Only way out | The line can leave a cell in only one direction - every other neighbour is already used, off the board, or a waypoint that is not due yet. |
| 1 | Do not strand a cell | The line must pass through every cell. If going one way would leave a cell with no way in or out, that way is wrong. |
| 2 | Do not cut the board in two | The rest of the line is one unbroken walk, so it cannot jump. A move that splits the untouched cells into two separate pockets can be ruled out. |
| 3 | Follow it and see it fail | Take a direction and keep applying the simpler rules. If the line paints itself into a corner, that direction was wrong - so the other one is right. |
What Griddle has published right now
| Game | Solver | Dailies | Calendar | Unlimited pool |
|---|---|---|---|---|
| Circuit | circuit/1.0.0 | 1097 | 2026-03-01 → 2029-03-01 | 1000 (easy 250, medium 250, hard 250, expert 250) |
| Eclipse | eclipse/1.0.0 | 1097 | 2026-03-01 → 2029-03-01 | 1000 (easy 250, medium 250, hard 250, expert 250) |
| Sentinels | sentinels/1.0.0 | 1097 | 2026-03-01 → 2029-03-01 | 1000 (easy 250, medium 250, hard 250, expert 250) |
Last published Sat, 15 Aug 2026 14:53:46 GMT.
No licensed content, no third-party IP
Our games are our own builds of classic pencil-puzzle mechanics, which are not anyone’s to own. The names, the artwork, the code and every board we publish came from us. Griddle has no affiliation with any other puzzle publisher and is not endorsed by one. You will not find another company’s trademarks in our game names, our URLs or our metadata.