Lambchop

Lambchop is a 2001 game by Dan Troyka, published online.

The game is played on a square board, say 5x5, initially empty.

Each player has just one piece (the lamb).

Rules:

• Initially, the players drop their lamb on an empty square
• On his turn, the player moves his lamb to an empty square
• if the square is unmarked, the player marks it for himself (thematically, the lamb just eaten the grass of that square)
• Wins the player with more marked squares

In the following position, White's turn to move, having each player marked nine squares. 

If White goes north to capture d5 and e5, he loses the game, since he would leave to Black three of the remaining seven grass (unmarked) squares. Then, White either captures b2 or a5, Black will capture the other.

There's a ZRF to play Lambchop. It includes several variants with different board sizes, and the use of more than one lamb per player.