The game has two players (A) The leader (B) player (you)

Four coins are placed on the corners of a rectangular rotating table. Some of the coins are facing head and some tail. Your goal is to arrange the coins so that all heads are up or all tails are up.

Here are the rules:

  1. You can ask the leader to flip any at most two coins but you can't see any coin ever.
  2. You can feel the table's orientation.
  3. Once you are done, the table will be rotated by the leader by either 90 or 180 or 270 or 360 degrees in clockwise direction.
  4. If all coins are either head or tail then a bell will ring.

Devise a strategy so that you will win the game.

NOTE: You shouldn't play the game randomly.

This puzzle is somewhat similar to puzzle Four cups on a table

  • $\begingroup$ Does he turn the table 90 degrees every time he's flipped 1 or 2 coins, or a random multiple of 90 degrees? $\endgroup$
    – Lolgast
    Feb 23, 2018 at 18:24
  • $\begingroup$ Welcome to puzzling. This is somewhat similar to this puzzle but not exactly the same, probably something to do with the symmetry of rectangle. Could you cite the source of this puzzle? $\endgroup$
    – ABcDexter
    Feb 23, 2018 at 18:28
  • 1
    $\begingroup$ You cannot see any coin? Ever? $\endgroup$
    – Lee Leon
    Feb 23, 2018 at 18:32
  • $\begingroup$ @Lolgast I've updated the question. $\endgroup$
    – sonus21
    Feb 23, 2018 at 18:32
  • $\begingroup$ @ABcDexter This question is made by me but somewhat similar to the puzzle you've cited. $\endgroup$
    – sonus21
    Feb 23, 2018 at 18:33

1 Answer 1


Order shown in picture below:

Diagonal means 2 diagonal coins. Short means the 2 coins on the short(or long) edge. Corner means corner. Order


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