Monster Latin Square #3
Place the letters A-I into the 81 squares so that no letter appears twice in any row, twice in any column, or twice in any 9-square region bordered by heavy lines. Some letters have been placed for you.
Key to interactive solving:
Enter letters in empty squares according to the instructions. Click/Tap "Check your answer" to check your (possibly incomplete) solution. But note that "Checking" a partial solution only verifies that your answers don't violate the conditions of the puzzle — it doesn't check that they match the correct solution!
Blue borders mark the squares pre-filled in the puzzle. Red borders mark rows, columns or regions that have a duplicated letter.
"Reset" will set the puzzle grid to the last configuration you checked, while "Start over" will clear every square except those given in the puzzle.
Use your browser's "Back" function to undo the last check.
Web programming by Matt Crawford.