Rules
Shade some cells. Among the cells you leave white, each digit appears at most once in every row and every column. The puzzle is finished when every cell is shaded or white and the rules hold.
- Digits stay. The board is an n×n grid. Every cell holds a digit from 1 to n. Those digits never change, and repeats are allowed.
- White digits are unique. Among the cells you leave white, no digit repeats in a row or a column. You do not have to keep every number from 1 to n.
- Shades never share a side. Two shaded cells never share an edge across or down. They may touch at a corner.
- One white group. The white cells stay one group, joined across or down. A diagonal touch does not connect them.
- At least two shades. The puzzle is finished when every cell is shaded or white, those rules hold, and at least two cells are shaded.
A finished 3×3. The shades are teal, the way a solved board looks, and no circles are drawn. The violet dot is the corner where the top-left shade meets the middle cell only at a point. The teal path joins the white cells.
- Shade
- Circle
- Digit
A circle is a cell you have marked white. An unknown cell is neither a shade nor a circle. A digit that shows once in its row and once in its column is not automatically circled. Every Hitori on PuzzleKite has one solution, and you can finish it by logic. The small windows in this guide are for the sentences. They are not sizes the play page deals.
First moves
Circle a sandwiched cell, shade the other copies of a digit you have circled, and circle the neighbours of a shade.
A sandwiched cell Easy
Two equal digits with one cell between them force that middle cell to stay white. The middle digit does not have to match them. Circle it. Do this before you look for a harder step. Rows and columns both count.
On a blank board the first circle is the 3 between the two 2s. The ring is amber, the circle is teal, and the cell takes the hint wash. Hint says: “These two equal digits sandwich this cell, so it must stay white.”
The same look circles two more sandwiches. The picture rings only the first:
- Circle the 2 between the two 1s in the bottom row.
- Circle the 2 between the two 1s in the first column.
This is the opening move on most easy grids, including the daily 6×6. The finished picture in the rules is where these circles, and the shades that follow them, end up.
Three in a row Easy
Three equal digits in a line cannot leave both ends white, and they cannot shade the middle, because the two ends would then sandwich a shade. The middle stays white and both ends are shaded.
The bottom row is 2 2 2. Hint does not use a separate sentence for the run. It circles the middle with the same sandwich sentence as section 2. The ring is on that middle 2. Neither end is shaded yet.
Once the middle is circled, the next hint shades the left-hand 2, as a copy of a digit you have already circled. The same look also shades the right-hand 2 and the 2 in the top row. Those belong withsection 2.
The how-to on the game lists the run of three on its own. Keep the pattern: middle white, both ends shaded. The figure shows the sentence the Hint button actually gives. On an easy grid this run is there, and Hint still says sandwich, then the white-digit copy.
A cell already white Easy
Once a cell is circled, every other copy of its digit in that row and that column is shaded. Circle first, then shade the copies. A circled cell is white. An unknown cell is not yet a copy you can shade.
The 2 on the left is already circled. The other 2 in that row is shaded. The new shade stays ink, the digit stays white, and there is no wash. Hint says: “This cell is already white, so the same digit elsewhere in the row or column must be shaded.”
Column 1 has no other 2, so this look shades one cell. On the blank walk of the first board, the same shade waits until the three sandwiches are circled. On the run of three, the same rule is the second hint: the circled middle shades the 2 on its left, and that look also shades the 2 on its right and the 2 above.
Beside a shade Easy
A shaded cell forces its neighbours to stay white. Circle them so you do not shade them next. The hint sentence says four neighbours. A cell on the edge has three, and a corner has two. Count the sides that exist. The order is north, then south, then west, then east, skipping a side the cell does not have.
The shade on the right edge has three neighbours: the cell above, the cell below, and the cell to its left. Hint circles the one above. The sentence still says four. “A shaded cell forces its four neighbours to stay white.”
The same look would circle all three. The picture rings only the north one. After that circle is placed, the next hint circles the cell below the shade. A corner is the same sentence with two neighbours.
An easy grid finishes with the sandwich, the copies of a digit you have circled, and these neighbours. The run of three is the pattern those grids are built from, and Hint still uses the sandwich sentence and thensection 2.
The other copies Easy
Two equal digits sitting next to each other cannot both stay white, and they cannot both be shaded. Every other copy of that digit in the same row, or the same column, is shaded. You can shade those copies while the pair itself is still unknown. This is not the run of three. A run of three shades its own ends. This step shades a copy that sits somewhere else in the line.
The two 5s at the end of the top row sit next to each other. The other 5 in that row is shaded. The ring is on that copy, not on the pair. The shade is ink, the digit is white, and there is no wash. Hint says: “This adjacent equal pair forces every other copy of that digit in the line to be shaded.”
This look shades only that one cell. The next hint circles the neighbour under it. The picture leaves that circle off. This is an easy step. Some 5×5 easy grids open on it. The daily 6×6 easy grids do not need it.
An easy grid finishes with section 2, including this step when an adjacent pair has another copy in its line. A corner that matches and one way out are easy sentences too, and an easy Hint almost never opens on them.
The white group
A corner that matches its neighbours, and a white cell with only one way out, keep the white cells joined.
A corner that matches Easy
If a corner digit matches both cells that share a side with it, that corner is shaded. The two neighbours stay white afterwards, by the rule in section 2. A corner that matches only one neighbour is not this step.
The top-left 3 matches the 3 below it and the 3 beside it, so the corner is shaded. Hint says: “This corner matches both neighbours, so the corner is shaded.” The sentence says nothing about four neighbours. The new shade is ink, with a white digit and no wash. The picture rings only the corner.
After this shade, the next hint circles the cell below, then the cell beside it. South before east. This sentence is easy. An easy 6×6 rarely opens on it, and no easy 3×3 with one solution does. The clean picture is a medium grid, because a later cell needs the pair split in section 4.
One way out Easy
A circled cell needs a way into the rest of the white group. If every side but one is already shaded, the open side stays white. Circle it. A side that is already white still counts as a way out, so a remaining unknown is not the only exit. This keeps the white cells in one piece before the grid is finished.
The bottom middle circle has shades on both sides. Its only open neighbour is the cell above, so that cell stays white. Hint says: “This white cell has only one exit left, so that neighbour stays white.” The circles on the left and right of the middle row still have another open side each, so they are not the sentence.
The blank grid is a different lesson. It opens on the three 1s along the bottom. This window is the later mark. An easy grid can finish without Hint ever saying this. It is still an easy sentence.
Split a pair
When two equal digits sit next to each other, exactly one of them stays white. Both tries use only the earlier marks.
Which of the two Medium
Two equal digits that share a side cannot both stay white, and they cannot both be shaded, so exactly one stays white. Try each side with the easy rules only. If one side breaks, keep the other, and place the marks that side forces. The cut and the one-cell try are not part of this trial.
The pair is the two 1s at the end of the top row. Keeping the right-hand 1 white and shading the left one breaks. Keeping the left one white survives. The first mark of that side is the 2 in the top-left corner. Hint says: “Exactly one of these two adjacent equal digits can stay white.”
After that circle, the next hint shades the other 2 in the column, because the 2 you circled is already white. It does not stay on the pair. The picture rings only the top-left 2.
Medium grids need this. A given medium grid may still open on a sandwich. The split comes when the easy rules stall. On a from-scratch pass the whole surviving side can wear this sentence, including cells that are not the pair. Hint places one cell. After that cell, a later copy often gets the cheaper “already white” sentence.
Both ways agree Medium
Sometimes both sides of an adjacent pair survive the easy rules, and they still force the same mark somewhere else. Place that mark. You do not yet know which of the two is the white one. The sentence is not “exactly one stays white”.
The pair is the two 4s in the second row. Both ways circle the 1 in the top row. Hint says: “Both ways through this adjacent pair force the same mark on this cell.” The picture rings only that 1.
One way shades the right-hand 4 and circles its three neighbours, including the top-row 1. The other way finishes the grid by the easy rules and circles that same 1. Both ways also circle the 1 at the end of the second row and the 2 under the pair. The next hints stay on this sentence: that 1, then the 2. They are not drawn yet.
This is uncommon. A medium grid you open will usually show the pair split first. Medium adds that split. This sentence is the other medium step, and only a few grids use it.
Where a shade would cut Hard
The white cells have to stay one group. If shading a cell would leave two white groups that cannot meet again, that cell stays white. Circle it. This is not the last exit. The last exit is one circled cell with a single open side. This one is a cell you have not marked, whose shade would split the group.
Eight cells are already marked. The last one is the top-left. If it were shaded, one white group would be the rest of the top row and the right-hand cell of the middle row, and the other would be the left column with the bottom middle. The two ink shades sit between them. Hint says: “Shading this cell would split the white region, so it must stay white.”
The blank grid opens on the bottom-right corner, not on this circle. The figure is the last mark. Hard grids add this, and not all of them. A 6×6 hard grid is more likely to finish with the try insection 6. Some other hard sizes finish on the cut and never try a cell.
What if Hard
When the earlier rules stall, pick one cell that still sees another copy of its digit and try one colour. Follow the easy rules, the pair split, and the cut. Do not start a second guess inside the first. If that colour breaks, the cell takes the other colour. If the shade breaks, the cell stays white. If the white breaks, the cell is shaded. The two sentences are different. Say which colour you tried.
This is a hard step. Most hard grids need it. Some finish on the cut and never try a cell. The daily grid does not need it. The worked try here is a circle. The other sentence, the one that shades, is the same kind of step with the colours swapped. A 6×6 hard grid often says that shade sentence. On some hard grids both colours survive and still agree on another cell. Hint uses the ordinary try sentence for that cell. It does not say the two ways agreed.
The shade breaks
Five marks are already on the board. Try a shade on the 1 in the top row, in the preview colour. The caption calls it the try. Do not leave it there.
The preview shade is the try. The violet rings are the circled 1s it seals. They are not red.
Leaving the 1 white adds nothing by itself and does not break. The contradiction is the shaded side. Hint says: “If this cell were shaded, that side contradicts, so it stays white.”
- The try has three neighbours, and each of them stays white: the 4 under it, the 3 on its left, and the 4 on its right. The hint sentence in section 2 says four neighbours. This cell has three.
- The new white 3 on the left shades the other 3 at the end of the top row, and the other 3 in the bottom-left corner.
- The new white 4 on the right of the top row shades the 4 in the third row.
- The new white 4 under the try shades the other 4 at the end of that row, and the other 4 in the bottom row.
- The white 3 in the top-left now has only one open side, so the cell under it stays white.
- The circled 1 at the end of the third row has every neighbour shaded. The circled 1 beside the bottom shade is sealed the same way. A white cell with no way out is the break.
Later on this same grid, after two more try-circles, Hint shades a 4 with “If this cell stayed white, that side contradicts, so it is shaded.” That is a separate hint. The picture stops at the circle. Hard adds the cut, or a one-cell try, or both. A given hard grid may use only one of them.
Common mistakes
Red shows only while error highlight is on. A shade in the error list stays ink, with a white digit and no wash. A cited circle gets a red wash, a red ring, and a red digit. A shaded cell does not turn red. Solved shades turn teal.
Both cells stay ink, with a white digit and no red wash. Check is already invalid. The Hint button waits. You do not have to finish the row.
Both circles wash red, and the digits turn red. Two white copies of one digit are a break before the row is finished. The Hint button waits.
Only the circle washes red. The three shades stay ink, and they are not in the error list. A white cell whose every neighbour is shaded is already disconnected. The Hint button waits.
The shade stays ink, with no ring and no wash. Check stays quiet while the grid is unfinished. Hint does not erase it. It still asks for the sandwiched 3.
A quiet shade on the bottom-right 1, and a quiet circle on the top-left 1, are the same lesson as the fourth picture: nothing is red, the grid is unfinished, and Hint still asks for the sandwiched 3. A shade on the sandwiched cell itself is also not red. That one is different: Hint’s mark is that same cell, so the button replaces the shade with the circle.
What to play next
Once the sandwiches feel quick, move up a setting. Each one adds a new idea.
- EasySandwiches and copiesThe daily size. Circle the sandwiched cells, shade the copies of a digit you have circled, and circle the neighbours of a shade. A 5×5 easy grid is the same lesson on a smaller board. Some of those open by shading the other copy of an adjacent pair.Play Easy →
- MediumSplit an adjacent pairWhen the easy marks stall, split an adjacent pair. Exactly one of the two stays white. Try each side with the easy rules only.Play Medium →
- HardA cut, or one tryWhen a shade would cut the white group in two, circle that cell. On a 6×6 hard grid the step you are more likely to need is a one-cell try. On some other hard sizes the cut finishes the grid and the try never comes.Play Hard →
5×5, 6×6 and 7×7 come in easy, medium and hard. 8×8 comes in easy and medium. 9×9 comes in easy. Try5×5 easy when you want the same easy lesson on a smaller board.
The daily puzzle is a 6×6 easy grid:today’s Hitoriorthe same setting in the game. Those grids finish with the sandwich, the white-digit copy, and the neighbours of a shade. Print packs are at printable Hitori. A 5×5, 6×6, or 7×7 sheet holds four puzzles. An 8×8 or 9×9 sheet holds two. Large print is one. The answer key starts on its own page, with the shades filled and the digits kept on the fill.
- GuideNurikabeGrow each island to its number and keep one sea.
- GuideLight UpLight every white cell. Start beside the 0s and 4s.
- GuideNonogramsFill cells from the clues. Overlap the long runs first.
- GuideStar BattlePlace stars so rows, columns and regions are exact.
- GuideHashiJoin numbered islands with bridges that never cross.
- GuideSudokuFill each row, column and box with the digits 1 to 9.
- GuideBinairoBalance every row and column with 0s and 1s.
- GuideSlitherlinkDraw one loop. Start from the 0s and the 3s.
- GuideKakuroFill each run so the digits meet the sum.
- GuideKiller SudokuCage sums and house totals do the work.
- GuideFutoshikiFollow the signs, then give each digit one home in the line.
- GuideMasyuDraw one loop. Turn on black pearls, go straight on white.