Object: Build fences and stalemate your opponent.
 
First the players drop a Rabbit each.
A Rabbit moves similar to a chess knight, but in two steps rather than one. First it moves one (two) step(s) in one direction, then two (one) step(s) orthogonally. Hence each player has two moves per turn.
 
All positions moved to or jumped over turn into an impenetrable barrier for both players.
 
You lose if you are stalemated.
 
The other variants use larger boards.
 
 
More freeware as well as real puzzles and games at http://karl.kiwi.gen.nz.