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About ABCD Logic Puzzles

ABCD Logic Puzzle Rules

The rules of ABCD Logic Puzzles are as follows:

• Place each letter A,B,C,D once in each row and column
• There are two blank squares in each row and column
• There are letters at the start/end of some rows and columns. Where present, those letters indicate which letter must come first/last in that row or column

Here is an image of the start position of an ABCD logic puzzle:

Noting the rules above, the 'C' above column one means that the first letter encountered in that column is a C. This means the first square in the column must be a C, *or* it is a blank and the C is in the second square in the column, *or* both the first and second squares in the column are blank and the third square in the column contains the C. This means that where a letter is given at the start of a region it can never appear in the fourth, fifth or sixth positions of the region (and vice versa if a letter appears at the end of a row or column it cannot appear in the first, second or third square of that region).

If you would like a visual explanation of the rules, here is a video outlining the above:

Play A Sample ABCD Logic Puzzle

If you'd like to have a go at solving an ABCD Logic Puzzle, then you can play the example shown above in our Online ABCD Logic Puzzle Player

If you enjoy this puzzle type, you can join our online Puzzle Connoisseur's Club for £12 or $17 a year and play a new ABCD Logic Puzzle puzzle every day of the year, together with many other fun and interesting logic puzzles.

Strategy and Solving Tips for ABCD Logic Puzzles

All our ABCD Logic Puzzles have a single solution that can be reached through the application of logical rules alone - no guessing is ever required. Here are a few pointers to help you get started with the example puzzle above:

• The C must go in the first square in the grid. We know that it must go in one of the first three squares in the column for the reasons outlined above. It cannot go in the second square, because the first square in row two must be a blank or a B, and it cannot go in the third square, because that cannot be a C due to the C at the end of row three. Therefore it must go in the first square in the grid.
• Now we have the C placed, we know that the C in column three cannot appear in the first square in that column. You might like to put an X in that square to remind yourself that it must be a blank.
• Likewise, you can put a blank in the final square of row five. This is because row five must end with a B, but column six must start with a B, which means that the B cannot appear as far down as the fifth square in column six. We also know the fourth square in row five cannot contain a B, since a B must appear in one of the first three squares of column four, and therefore we can place the B into the fifth square of row five.