The full logical solve of the hard Light Up for September 29 to October 5, 2026, 14 × 14. 82 steps, 5 techniques, no guessing. Step through it, or jump to any step below.
The 0 at row 1, column 7 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 4, column 3 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 5, column 9 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 10, column 6 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 13, column 2 has no bulbs beside it, so none of its open sides can take one.
The 0 at row 13, column 12 has no bulbs beside it, so none of its open sides can take one.
The 1 at row 12, column 1 still needs one bulb and has exactly one open side. It takes the bulb.
Suppose a bulb sat at row 1, column 2. Its light closes the cells it reaches, and the 1 at row 2, column 3 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 3, column 5. Its light closes the cells it reaches, and the 1 at row 2, column 6 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 3, column 8. Its light closes the cells it reaches, and the cell at row 2, column 7 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 4, column 13. Its light closes the cells it reaches, and the 1 at row 3, column 14 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 6, column 2. Its light closes the cells it reaches, and the 2 at row 7, column 1 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 6, column 6. Its light closes the cells it reaches, and the 1 at row 5, column 7 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 5, column 4. Its light closes the cells it reaches, and the 2 at row 6, column 5 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 7, column 4. Its light closes the cells it reaches, and the 2 at row 6, column 5 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 8, column 2. Its light closes the cells it reaches, and the 2 at row 7, column 1 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 10, column 10. Its light closes the cells it reaches, and the 2 at row 11, column 11 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 2 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 10. Its light closes the cells it reaches, and the 2 at row 11, column 11 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 2 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 1, column 1. That forces bulbs at row 2, column 2 and row 5, column 2, and then the 2 at row 7, column 1 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 1, column 5. That forces bulbs at row 2, column 2 and row 3, column 4, and then the 1 at row 2, column 6 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 1, column 10. That forces 11 more bulbs, and then the 1 at row 7, column 11 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 1, column 12. That forces 11 more bulbs, and then the 1 at row 7, column 11 would be left without room for its bulbs. So that cell has no bulb.
Suppose the cell at row 2, column 8 had no bulb. That forces 9 more bulbs, and then the cell at row 2, column 2 would have nothing left to light it. So it takes a bulb.
Suppose the cell at row 2, column 12 had no bulb. That forces 5 more bulbs, and then the cell at row 4, column 9 would have nothing left to light it. So it takes a bulb.
Suppose a bulb sat at row 5, column 11. Its light closes the cells it reaches, and the 1 at row 4, column 12 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 3, column 1. That forces three more bulbs, and then the 2 at row 7, column 1 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 3, column 4. Then the 1 at row 2, column 6 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 3, column 7. That forces 8 more bulbs, and then the cell at row 2, column 2 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 3, column 9. That forces 8 more bulbs, and then the cell at row 2, column 2 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 3, column 10. That forces 10 more bulbs, and then the cell at row 2, column 2 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 3, column 11. That forces 10 more bulbs, and then the cell at row 4, column 9 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 3, column 13. That forces 7 more bulbs, and then the cell at row 2, column 2 would have nothing left to light it. So that cell has no bulb.
The 1 at row 3, column 14 still needs one bulb and has exactly one open side. It takes the bulb.
Suppose a bulb sat at row 4, column 5. That forces 9 more bulbs, and then the cell at row 5, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 5, column 2. That forces three more bulbs, and then the 2 at row 7, column 1 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 6, column 1. That forces three more bulbs, and then the 2 at row 6, column 5 would be left without room for its bulbs. So that cell has no bulb.
The 2 at row 7, column 1 still needs two bulbs and has exactly two open sides. Every one takes a bulb.
Suppose a bulb sat at row 6, column 12. That forces 6 more bulbs, and then the 1 at row 7, column 11 would be left without room for its bulbs. So that cell has no bulb.
Suppose a bulb sat at row 6, column 13. That forces 12 more bulbs, and then the cell at row 13, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose the cell at row 7, column 5 had no bulb. That forces 6 more bulbs, and then the cell at row 7, column 5 would have nothing left to light it. So it takes a bulb.
Suppose a bulb sat at row 7, column 13. That forces 11 more bulbs, and then the cell at row 13, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 8, column 9. That forces 13 more bulbs, and then the cell at row 13, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 8, column 11. That forces 9 more bulbs, and then the cell at row 13, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 5, column 13. That forces 7 more bulbs, and then the cell at row 13, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 9, column 4. That forces three more bulbs, and then the cell at row 13, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 9, column 5. That forces 7 more bulbs, and then the cell at row 13, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 9, column 11. That forces 12 more bulbs, and then the cell at row 13, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 9, column 14. That forces 6 more bulbs, and then the cell at row 13, column 3 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 10, column 3. That forces 14 more bulbs, and then the cell at row 9, column 6 would have nothing left to light it. So that cell has no bulb.
Suppose a bulb sat at row 12, column 4. Its light closes the cells it reaches, and the 1 at row 11, column 3 would be left without room for its bulbs. So that cell has no bulb.
The 2 at row 13, column 4 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 13, column 3: the one at row 12, column 3. The bulb goes there.
The 1 at row 11, column 3 already has one bulb beside it. Its other open side gets no bulb.
The 2 at row 11, column 11 still needs two bulbs and has exactly two open sides. Every one takes a bulb.
The 1 at row 11, column 13 still needs one bulb and has exactly one open side. It takes the bulb.
Nothing else can light the cell at row 10, column 4: 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 11, column 6: the one at row 11, column 7. The bulb goes there.
The 1 at row 5, column 7 still needs one bulb and has exactly one open side. It takes the bulb.
The 1 at row 2, column 6 still needs one bulb and has exactly one open side. It takes the bulb.
The 1 at row 2, column 4 already has one bulb beside it. Its other open side gets no bulb.
The 2 at row 6, column 5 still needs one bulb and has exactly one open side. It takes the bulb.
Nothing else can light the cell at row 1, column 3: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
The 1 at row 2, column 3 already has one bulb beside it. Its other open side gets no bulb.
Nothing else can light the cell at row 3, column 2: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
The 1 at row 4, column 2 already has one bulb beside it. Its other open side gets no bulb.
Nothing else can light the cell at row 2, column 1: 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 10: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
The 1 at row 7, column 10 already has one bulb beside it. Its other open side gets no bulb.
The 1 at row 9, column 10 already has one bulb beside it. Its other open side gets no bulb.
Only one cell can still light the cell at row 6, column 9: the one at row 6, column 11. The bulb goes there.
The 1 at row 7, column 11 already has one bulb beside it. Its other open side gets no bulb.
The 1 at row 4, column 12 still needs one bulb and has exactly one open side. It takes the bulb.
Only one cell can still light the cell at row 4, column 9: the one at row 4, column 10. The bulb goes there.
The 2 at row 2, column 11 still needs one bulb and has exactly one open side. It takes the bulb.
Nothing else can light the cell at row 7, column 14: every cell that sees it is lit, dotted or behind a black cell. It needs its own bulb.
The 1 at row 8, column 14 already has one bulb beside it. Its other open side gets no bulb.
Only one cell can still light the cell at row 8, column 13: the one at row 9, column 13. The bulb goes there.
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 13, column 8: 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 13, column 13: the one at row 14, column 13. The bulb goes there.