On a Shingoki Puzzle board, your next step is the orthogonally adjacent cell that keeps the loop single, branch-free, and consistent with the current clue's color, turn direction, and segment sum, all verified by the in-browser loop validator before the move is accepted. Each press of an arrow key from the selected cell proposes exactly one new cell; that cell is kept only if it sits next to the current end, does not reuse any earlier body cell, and leaves the route on track to satisfy every numbered black and white clue when the loop eventually closes. The board is a four by four grid with one disclosed fixture: a black 6 in the upper-left cell and a white 3 immediately to its right. There is no random scrambling, so the same starting position is reused every run and the same twelve accepted movements close the same perimeter loop, yielding 880 points from the 1,000-point starting value.
That single sentence is the operational definition. Treat the loop as a path you build one cell at a time rather than a picture you plan in advance. Every clue is a constraint on what the route must look like when it passes through that cell, and the constraint applies to whichever of the two arms is still in motion when you arrive. Choosing the next step therefore means deciding which clue you want to honor first and which orthogonally adjacent cell satisfies the current end's rule without locking the rest of the grid into a dead branch.
What the loop must satisfy at every step
A Shingoki loop has three overlapping requirements, and the page rejects a step that breaks any one of them. A complete route that passes the per-step checks must still pass a closing check before it counts as solved.
- One closed, non-branching loop. Every body cell is unique. The only cell that may be revisited is the starting cell, and only once, at the moment of closure.
- Clue shape at every clue cell. On a black circle the loop must turn, so the two arms are perpendicular. On a white circle the loop must pass straight through, so the two arms are collinear.
- Clue number at every numbered circle. The number equals the sum of the lengths of the two straight arms that meet at that circle, measured in cells along each direction until the first turn.
The validator enforces all three. A move that re-enters a body cell is rejected immediately as a dead end, because a single loop cannot self-intersect. A closing move that returns to the start while any clue has the wrong circle shape, value, or geometry marks the loop deadlocked rather than solved. A closing move back to the start is rejected if any clue is still missing, the geometry is wrong, or the value at any clue does not match.
Read each clue before you extend the line
Before choosing the next cell, read the clue you are currently sitting on. The clue dictates what direction the next arm must run, so it constrains which of the four neighbors is even a legal candidate.
If the current cell is a black circle, you have to leave it at a right angle to the direction you arrived from. The clue number is then the sum of the cells you travel in each of the two straight segments that meet at that corner. On the disclosed board the black 6 sits in the upper-left corner cell, so when you arrive going right the next arm must go down, and vice versa; whichever way the corner is entered, the two arms are each three cells long, producing 3 + 3 = 6.
If the current cell is a white circle, you must leave it in the same direction you arrived from. The two straight arms run along a single line through the cell, and the number is again the combined length of those two segments. On the disclosed board the white 3 sits immediately to the right of the black 6; entering from the left, the forward arm runs two cells to the corner and the backward arm runs one cell back to the black clue, producing 2 + 1 = 3.
The order in which you visit clues matters less than the geometry you commit to. A black clue visited out of order can still be satisfied as long as the arm lengths work out. A white clue is unforgiving: any deviation from straight violates its rule before numbers are even checked, so a white clue blocks the route the moment it is touched out of line.
How to choose the next step on the four by four fixture
The disclosed fixture's intended route is the full outer perimeter of the four by four grid. Walk through it in this order.
- Press Space or Enter on the black 6 in the upper-left to drop the keyboard marker onto that cell. The route begins there.
- Press the right arrow three times to draw the top edge, visiting cells (0,1), (0,2), and (0,3). The white 3 at (0,1) is passed straight through, and its two arms end at the next corner and the previous clue.
- Press the down arrow three times to draw the right edge, visiting cells (1,3), (2,3), and (3,3). The corner at (0,3) is a regular turn with no clue, so the line simply bends.
- Press the left arrow three times to draw the bottom edge, visiting cells (3,2), (3,1), and (3,0). No clues appear on this segment, so the line continues straight through each cell.
- Press the up arrow three times to draw the left edge, visiting cells (2,0) and (1,0), and returning into (0,0), the starting black 6. The loop is now closed at its starting cell.
- Confirm the completion screen shows the perimeter route accepted and a score of 880.
That sequence is twelve unique body cells and twelve accepted movements. Every step is orthogonal, every body cell is new, every clue is satisfied by the geometry of the perimeter, and the loop closes only at the start. The arithmetic of the score is worth knowing because it tells you the cost of every accepted move: 1,000 − 10 × 12 = 880. On that twelve-step perimeter, 1,000 − 10 × 12 = 880, so that described route scores 880 from the 1,000-point starting value.
| Clue type | Shape rule | Number rule | On the disclosed fixture |
|---|---|---|---|
| Black circle | Line turns; the two arms are perpendicular | Number equals the combined length of the two arms in cells | Black 6 at the upper-left corner; each arm is 3 cells, so 3 + 3 = 6 |
| White circle | Line continues; the two arms are collinear | Number equals the combined length of the two arms in cells | White 3 on the top edge; forward arm 2 cells, backward arm 1 cell, so 2 + 1 = 3 |
| Plain cell | Line passes through or turns freely | No number, no constraint | Remaining ten cells form the unconstrained perimeter |
Recover from a rejected move without restarting
The page rejects moves for one of three reasons, and only the first is recoverable without losing progress. Knowing which is which saves the run.
- Rejected move, route still open. If the next arrow press tries to step off the board, the browser ignores the input. The route stays open, the score stays where it was, and a different arrow can be pressed from the same position.
- Dead-end detection while the loop is still open. Re-entering any cell other than the start creates a self-intersection or branch, which the validator flags immediately. The marker stays put; restart to keep going.
- Closed-but-deadlocked. If the route returns to the start but a clue is wrong, with the wrong shape, wrong value, missing clue, or wrong geometry, the page marks the loop deadlocked rather than solved. Restart resets the route and the 1,000-point starting value; double-press Escape toggles the shared simulated spreadsheet boss screen and toggles back.
The most common mistake is choosing a next step that closes the loop too early. Returning to the start before the white 3 has been passed straight through is treated as a closure and then fails the post-game audit, even though the body looks complete. Treat returning to the start as the last move, not a convenience move.
Score, edge arrows, and the boss key
The score starts at 1,000 and falls by 10 with every accepted arrow press, so score equals 1,000 minus 10 times the number of accepted steps. On the disclosed fixture the described full perimeter satisfies both clues and scores 880 from the 1,000-point starting value. Board-edge arrows do nothing: pressing up while on the top row or right while on the rightmost column is silently ignored rather than counted as an accepted step. Restart wipes the route and resets the score to 1,000, which makes it cheap to try a different opening direction from the black 6 if you want to confirm the geometry for yourself.
For puzzles with similar loop and shading rules, the closest siblings are Masyu, an orthogonal loop with black-and-white turn rules but no numbers, and Pipes, where every tile must be rotated until openings match. If you want a numbered-path challenge rather than a loop challenge, Numberlink pairs matching endpoints with continuous orthogonal paths on the same four by four size class.
When you want to put the rules into practice on the disclosed fixture itself, open the Shingoki Puzzle page, focus the board, and walk the twelve-step perimeter described above. The keyboard cursor, the value-aware validation, and the dead-loop detection are all live, so the page will tell you the moment a step violates any of the three rules.
Related reading: How to Choose Your Next Step in a Numeric Ranking Game.
Related reading: How to Avoid Common Mistakes in Thermometers Puzzle.