Think sudoku without the cages. Each row and column contains one of each number 1-6.

Appreciate that this walkthrough covers one path of logic, even though there may be multiple legitimate logic paths.

**(5/36)**

The 1’s on the board are not adjacent to another 1; the other four 1’s are. The 1 in the fifth column cannot go in the top row, obviously. If it’s above the 5, it won’t be adjacent to another 1. It can’t go diagonally to the other 1 either, since that 1 is not adjacent to another 1. So the 1 in Column 5 goes in the highlighted cell. This of course means that another 1 is down-right from that 1.

As for the 1 in Row 2, it has to go in Column 3 so as not to be adjacent to the corner 1. Then the final 1 must be Row 3, Column 2.

**(9/36)**

The main diagonal is obviously not the one that has a 1 in it. Since the highlighted cell is prime but not 2 or 5, it must be 3.

**(10/36)**

You can now finish that row. The highlighted cell cannot be 4, so it is 6. The 4 then is in Column 3.

**(12/36)**

The remaining corners must be 2, 3, and 4. Two of those are on the prime-only diagonal, so the highlighted cell must be 4. The far right column already has a 2, so the top right corner is 3 and the bottom left corner is 2.

**(15/36)**

The highlighted cell must be prime, but there’s a 5 in the same column. Now we know that 2’s cannot be adjacent to each other, so highlighted cell cannot be 2 either. So it is 3.

**(16/36)**

Now you can get a bunch. The highlighted cell can no longer be 3, so it is 5. The other cell in the left column is 3 then.

Row 6, Column 5 can only be 6. Right above it cannot be 4 (same row), so it is 2. So the top cell in that column is 4.

In the far right column, the second from top cannot be 5 (same row), so it is 6. Third from bottom, then, is 5.

**(23/36)**

The highlighted cell is on the prime-only diagonal. It cannot be 3 or 5 (same row), so it is 2.

**(24/36)**

The highlighted cell or the one to its right must be a 3. The cell next to the 1 cannot be adjacent to a 4, since that row and the one above it already have a 4. So the highlighted cell must be 3, meaning the one next to it is 5.

**(26/36)**

The highlighted cell must be prime but not 3 (same column) or 2 (same row), so it is 5. What’s left for that row is 6 and 3, so 3 is in the third cell and 6 in the fourth.

**(29/36)**

The highlighted cell cannot be 1, 2, 3, 5, 6. It is 4, meaning the other number in that row is 6.

**(31/36)**

The highlighted cell cannot be 1, 3, 4, 5, 6, so it is 2. The other cell in that row, then, is 4.

**(33/36)**

The last three cells are obvious, since their columns are all 5/6 filled.

TRY HENRY820’S OTHER LOGIC PUZZLES!