15 or Slider Puzzle – Walkthrough (Sam Loyd/1879)

Positions are numbered from 1 to 16, from left to right, top to bottom. So are the tiles. When a position is mentioned, it’s regardless the number on the tile on that position. When a number is mentioned it refers to the number on the tile. Always start from the left top corner (position 1). Once a tile is in place, the order shouldn’t be changed anymore.

• Put the tiles numbers 1, 2, and 3 in place at positions 1, 2 and 3.
• Put tile number 4 at position 8 (below where it’s supposed to go)
• Slide tile number 1 down, tile numbers 2 and 3 and position 4 to the left.
• Slide tile number 4 up.
• Slide position 3 down
• Slide tile numbers 3 and 2 right
• Slide tile number 1 up

You should have a line numbered from 1 to 4 on the top row. This principle is the basic to solve any kind of slider of any size. Repeat the above until the last row. In case of a 15 Slider it means you have to repeat this for the second and third row, leaving row 4 to solve. With some luck, this one is in order already, if not, read on.

• Rotate the bottom two rows counter clockwise two positions.

Tile number nine should now be on position 14, tile number 10 on position 13 etc.

• Rotate the right two positions from rows 3 and 4 (they should contain tile number 13, 14 and 15) so that tile number 13 is on position 15, number 14 is on position 15 and number 15 is on position 12.
• Rotate the bottom two rows clockwise until the tiles are in the right place.

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