How to solve a mirror grid puzzle
Start with one filled tile. Count its row from the top and its column from the left. Transform that location, then repeat for the other filled tiles. Empty locations matter too: an extra tile is still a mismatch.
Mirror left to right
Keep each row the same. Column 1 becomes 4, 2 becomes 3, 3 becomes 2, and 4 becomes 1. A tile at row 2, column 1 lands at row 2, column 4.
Mirror top to bottom
Keep each column the same. Row 1 becomes 4 and row 2 becomes 3. A tile at row 1, column 3 lands at row 4, column 3.
Rotate 90 degrees clockwise
For this four-by-four board, new row equals old column. New column equals 5 minus old row. A tile at row 1, column 2 lands at row 2, column 4. Unlike a reflection, four quarter-turns bring the whole pattern back.
Practice without chasing a score
Check pattern reports the number of cells that differ. Preview solution lets you inspect the transformed pattern, then return to the tiles you selected. Changing the rule or moving to another pattern clears your answer. Six patterns cycle in order; there is no timer or ability rating.
