Unusual Checkers

Unusual online checkers that you have never played. This game is similar to conventional checkers, but with unusual rules:
- Normal checker is not visible until the enemy’s checkers come close;
- A king is always visible to the enemy;
- If one player has a king, he can see all the opponent's checkers;
- To beat is required;
- And the usual checker and king can beat back;
- King able to move to an arbitrary number of fields on the selected diagonal, and both forward and backward.

- The game ended with the following conditions if:
* the enemy has not any checkers;
* if the enemy does not remain any strokes;
* after 20 move any checker has not beaten;