How to Solve

Every Handmade Hanjie puzzle can be solved using a combination of the techniques below, usually working on just one row or column at a time - no guessing required. You'll see these names again on the Example Solve pages, linked back to here whenever they come up.

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Reasoning

Actions

These techniques all change something on the grid directly - a cell gets filled in, or ruled out as blank.

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Overlap Method

A clue tells you how many cells are in a block, but not exactly where they start. Try sliding the block as far to one end as it'll go, then as far the other way - anywhere those two extremes still cover the same block must be filled either way, whatever the real position turns out to be.

Before

7

Apply the rule

7

After

7

A block of 7 in a row of 10. Slide it as far left as possible and it covers cells 1-7; as far right as possible and it covers cells 4-10. Cells 4-7 are covered either way, so they're filled immediately.

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Anchored Overlap

This works just like the Overlap Method, but anchored around whatever cells you already know belong to a block. Slide the block as far one way as it can go while still covering them, then as far the other way - anywhere both extremes still cover must be filled too.

Before

41

Apply the rule

41

After

41

The first clue here is a 4. Cell 2 is filled and is within 4 cells of the start of the line - close enough that it can only belong to that block. Slide it as far left as possible and it covers cells 1-4; as far right as possible and it covers cells 2-5. Either way, cells 3 and 4 are covered, so they're filled in now.

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Length Bound

Works like Anchored Overlap, but the anchor's exact clue isn't pinned down - it could still be more than one candidate, of different lengths. Fill only as far as the shortest candidate guarantees, since claiming any more would assume it's the longer one.

Before

34

Apply the rule

34

After

34

Cell 5 is filled and could be either the 3 or the 4 - there's room to the left for the 3 to fit first, so both are still live. Either way the block is at least 3 long, so cells 6 and 7 fill in too - but not cell 8, since that would only be guaranteed if it turned out to be the 4.

Actions

Ruling Out

A cell is ruled out as blank once no remaining clue could possibly reach it.

Before

4

Apply the rule

4

After

4

This line has just one clue: a block of 4. Cells 4, 5 and 6 are already filled, so the block must sit somewhere within cells 3-7. Nothing else in the line could be part of it, so cells 1, 2, 8, 9 and 10 are ruled out as blank - even though cells 3 and 7 themselves are still unknown.

Actions

Exact Start

When a block's exact starting position is known, there's nothing left to work out - fill the whole block, and mark the next cell as being blank.

Before

41

Apply the rule

41

After

41

This block's exact start is known - right after the blank at cell 1 - and its clue must be the 4. With nothing left to work out, the whole block can be filled in, cells 2-5, and cell 6 is marked as blank immediately after.

Actions

Bridge Gap Rule

A single cell sitting between two filled blocks that would merge them into one if it were filled. If no clue could possibly be that combined size, the cell can't be filled - so it's blank instead.

Before

23

Apply the rule

23

After

23

Filling the gap would merge the two blocks into a block of at least 4 cells, but there's no clue of 4 or longer here - so it must be blank.

Actions

Merge Blocks

Two separate groups of filled cells are known to belong to the same clue. A block never has a gap in the middle, so everything between them must be filled too.

Before

5

Apply the rule

5

After

5

The clue here is a 5, and cells 4 and 7 are both known to be part of it - the only way they can both belong to the same block is if it runs the whole way between them. Cells 5 and 6 fill in to join them, though it's still not clear whether the block extends one cell further to the left or the right.

Actions

Seal Ends

Once a filled block is already as long as the biggest clue it could still possibly be, it can't grow any further. Seal its ends by marking the cell on either side as blank. Rare in practice, since a block usually already has at least one side anchored by an earlier move by the time this comes up - this only applies when a block of known size is genuinely floating with no blank next to it on either side yet.

Before

42

Apply the rule

42

After

42

This block is already 4 cells long, and 4 is the biggest it could possibly be - so it can't grow any further. Neither side is blank yet, so both cells 1 and 6 - its two ends - are sealed as blank in the same move.

Reasoning

The techniques above all change something on the grid directly. Sometimes though, what's missing isn't a fill or a blank - it's knowing more about which clue a filled block actually is. That doesn't always mean pinning down one exact answer - sometimes it's just ruling out a possibility. Either way, the techniques below work that out, and are often a necessary step before you can use one of the actions above.

Reasoning

Size Rules It Out

A filled block can't belong to a clue smaller than its own current size - so if it's already bigger than one of the remaining clues, that clue is ruled out, whatever else is still unknown about the line.

Before

26

After

26
6
6
6
6

This block is already 4 cells long, too long to be the block of 2. That leaves just the 6, so the block must be that one.

Reasoning

Block Match

If a line can be split into as many distinguishable blocks as there are clues left, each block must match a clue, in order. Blocks count as distinguishable either because a blank separates them, or because merging them would create a block bigger than any of the possible matching clues. Any block matched this way is fully identified - and if a whole section has no clue left for it, it must be blank.

Before

243

After

243
2
4
4
3
3

Cells 2 and 5-6 are filled, but merging them would make a block of 5, too big for the candidate clues, so they must be two separate blocks - namely 2 and 4, matching the first two clues. Cells 12 and 14 sit after a blank, so again must be a different block - both must be the 3 as that is the only clue left. The blank at cell 17 splits off the last section, which has no filled cell and so no clue left for it - it must be blank.

Reasoning

Room Check

A clue doesn't just need to fit itself into a section - it needs to leave room for whatever else has to come before or after it too. If a candidate clue can't do that, it's ruled out.

Before

24

After

24
2

Cell 5 is filled, so there's a block somewhere in this section, and cell 7 is blank, bounding it on the right. It could be either the 2 or the 4 - but the 4 doesn't leave enough room here for the 2 to fit too (with a gap between them), so it must be the 2, and the 4 has to be in the section on the right instead.