There are five pieces (light or dark) and one ball per side. You must either move one of your pieces or pass your ball.
Pieces move like knights to any empty square. The piece with the ball may not move.
The ball may be passed in a straight unobstructed line to any of your pieces. The ball may passed horizontally, vertically, or diagonally. You may pass the ball as many times as you like on a given turn, so long as no piece touches the ball more than once. When you are done with the partial moves, click the lightning sign at the menu bar.

You win when you have passed your ball to the opponent's end of the board.

Queen Variant: Each player has a specially marked piece which moves like the queen in Chess (no capturing though).

'Colour Variant':
   Same rules as basic version, but with this addition:
   You have another partial move when (after moving a piece) your man lands on a square of your colour.
   Click the pass button to end such a sequence of hops.
'Tournament Variant':
   A man becomes 'ineligible' when he has passed a ball.
   After a move it becomes eligible again.
   If an opponent moves into a square adjacent to your ball, you MUST pass on your next turn,
   if a pass is possible.
'Karl's Variant':
   Same rules as Tournament Variant, but for a non-ball-carrying piece
   eligibility changes with every move.

Variants 5-10: Similar as above, but on the 8x8 board.
Variants 11-15: Similar as above, but on the 9x8 board.

 
More freeware and real puzzles and games at my homepage: karl.kiwi.gen.nz.