Instructions:

The board

The board of Quantum Minesweeper is a superposition of several "classical minesweeper" boards, i.e. each superposed board has several mines in differen cells. Each board has a probability of being measured, which can change during the game.

The moves:

The player can perform one of the following measurements:

• Classical measurement : Measures if there is a mine at the cell or not.
  Probabilistic results:
  1. Detected and triggered a mine --> you lose the game
  2. Detected there is no mine --> all boards with mine disappear; can decrease the number of superpositions
• Interaction-free measurement : A unique quantum measurement that measures if there is a mine at the cell.
  Probabilistic results:
  1. Detected and triggered a mine [half the probability of a classical measurement] --> you lose the game
  2. Detected and did not trigger a mine --> all boards with no-mine disappear; can decrease the number of superpositions
  3. Don't know --> changes the boards probabilities, but not the number of superpositions.
• Entropy measurement : Information on entanglement (do not affect superpositions).
  Deterministic numerical result:
  1. Zero means not entangled; either all superpositions have a mine in cell, or all superpositions do not have a mine in cell.
  2. Greater than zero means entangled; at least two boards have different cell occupation (one has mine another do not); larger number indicates more equal probability of having and not having a mine.

Information:

After each measurement, a number appears on the main board:

• A black number indicates the average number of adjacent mines in all the superposed boards.
• A red number (following entropy measurement) indicates the entropy of that cell.

How to win:

Mark correctly all the superpositions in all the user boards. Right click on a cell in the user boards marks a mine with the flag symbol , left click marks an empty cell. If the marking of the mines in the user board is identical to the true solution, the player wins.