The full logical solve of the hard Light Up for September 22 to September 28, 2026, 14 × 14. 62 steps, 5 techniques, no guessing. Step through it, or jump to any step below.
The 0 at row 1, column 4 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 1, column 13 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 6, column 9 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 6, column 14 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 8, column 12 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 10, column 4 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 13, column 10 has no bulbs beside it, so none of its open sides can take one.
The 2 at row 2, column 4 still needs two bulbs and has exactly two open sides. Every one takes a bulb.
The 1 at row 14, column 11 still needs one bulb and has exactly one open side. It takes the bulb.
The 1 at row 13, column 11 still needs one bulb and has exactly one open side. It takes the bulb.
Only one cell can still light the cell at row 1, column 14: the one at row 2, column 14. The bulb goes there.
Nothing else can light the cell at row 7, column 7: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
Nothing else can light the cell at row 8, column 8: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
The 1 at row 8, column 9 already has one bulb beside it. Its other open sides get no bulb.
Nothing else can light the cell at row 8, column 14: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
The 1 at row 9, column 14 already has one bulb beside it. Its other open sides get no bulb.
Only one cell can still light the cell at row 9, column 12: the one at row 9, column 10. The bulb goes there.
Nothing else can light the cell at row 1, column 11: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
Only one cell can still light the cell at row 7, column 9: the one at row 7, column 13. The bulb goes there.
The 3 at row 4, column 12 still needs three bulbs and has exactly three open sides. Every one takes a bulb.
Nothing else can light the cell at row 4, column 14: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
Suppose a bulb sat at row 1, column 6. Its light closes the cells it reaches, and the 2 at row 2, column 7 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 1, column 8. Its light closes the cells it reaches, and the 2 at row 2, column 7 would be left without room for its bulbs. So that cell has no bulb.
Only one cell can still light the cell at row 1, column 5: the one at row 1, column 7. The bulb goes there.
Suppose a bulb sat at row 5, column 6. Its light closes the cells it reaches, and the 2 at row 6, column 7 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 6, column 5. Its light closes the cells it reaches, and the 3 at row 7, column 6 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 7, column 2. Its light closes the cells it reaches, and the 2 at row 6, column 1 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 8, column 5. Its light closes the cells it reaches, and the 3 at row 7, column 6 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 10, column 7. Its light closes the cells it reaches, and the 2 at row 9, column 8 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 11, column 14. Its light closes the cells it reaches, and the 2 at row 12, column 13 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 12, column 3. Its light closes the cells it reaches, and the 3 at row 13, column 4 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 12, column 5. Its light closes the cells it reaches, and the 3 at row 13, column 4 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 13, column 14. Its light closes the cells it reaches, and the 2 at row 12, column 13 would be left without room for its bulbs. So that cell has no bulb.
Only one cell can still light the cell at row 10, column 14: the one at row 12, column 14. The bulb goes there.
Nothing else can light the cell at row 13, column 13: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
The 2 at row 12, column 13 already has two bulbs beside it. Its other open side gets no bulb.
Suppose a bulb sat at row 14, column 3. Its light closes the cells it reaches, and the 3 at row 13, column 4 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 14, column 5. Its light closes the cells it reaches, and the 3 at row 13, column 4 would be left without room for its bulbs. So that cell has no bulb.
Nothing else can light the cell at row 14, column 4: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
Suppose a bulb sat at row 13, column 7. Its light closes the cells it reaches, and the 1 at row 14, column 6 would be left without room for its bulbs. So that cell has no bulb.
The 1 at row 13, column 8 still needs one bulb and has exactly one open side. It takes the bulb.
The 1 at row 14, column 6 still needs one bulb and has exactly one open side. It takes the bulb.
The 3 at row 13, column 4 still needs two bulbs and has exactly two open sides. Every one takes a bulb.
The 1 at row 12, column 1 still needs one bulb and has exactly one open side. It takes the bulb.
Nothing else can light the cell at row 14, column 1: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
Suppose a bulb sat at row 1, column 1. That forces 6 more bulbs, and then the cell at row 6, column 8 would have nothing left to light it. So that cell has no bulb.
Nothing else can light the cell at row 1, column 2: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
Suppose a bulb sat at row 2, column 6. That forces a bulb at row 5, column 7, and then the cell at row 6, column 8 would have nothing left to light it. So that cell has no bulb.
The 2 at row 2, column 7 still needs one bulb and has exactly one open side. It takes the bulb.
Only one cell can still light the cell at row 2, column 6: the one at row 6, column 6. The bulb goes there.
The 2 at row 6, column 7 already has two bulbs beside it. Its other open side gets no bulb.
The 2 at row 6, column 1 still needs two bulbs and has exactly two open sides. Every one takes a bulb.
Only one cell can still light the cell at row 5, column 7: the one at row 5, column 5. The bulb goes there.
The 3 at row 7, column 6 still needs one bulb and has exactly one open side. It takes the bulb.
Suppose a bulb sat at row 9, column 2. Its light closes the cells it reaches, and the cell at row 10, column 3 would have nothing left to light it. So that cell has no bulb.
Nothing else can light the cell at row 9, column 3: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
Nothing else can light the cell at row 10, column 2: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
Suppose the cell at row 9, column 7 had no bulb. That forces bulbs at row 10, column 8 and row 11, column 7, and then the cell at row 13, column 9 would have nothing left to light it. So it takes a bulb.
The 2 at row 9, column 8 already has two bulbs beside it. Its other open side gets no bulb.
Suppose a bulb sat at row 11, column 9. Its light closes the cells it reaches, and the cell at row 10, column 8 would have nothing left to light it. So that cell has no bulb.
Nothing else can light the cell at row 10, column 9: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
Nothing else can light the cell at row 11, column 8: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.