Copyright (c) 2002 Walter Joris

This game is played on a 4x3 board with the following setup:

TURN - On each turn, each player may pass or move one friendly stone.
Each stone moves in a L fashion, i.e., it slides (orthogonally or diagonally) over a straight line of empty cells and just before reaching an obstacle (board edge or another stone), it must make a 90 turn (to the left of to the right) and move at least one more cell, until it finds another obstacle (it's invalid to stop in the middle of this double path).
A stone already at the last row cannot move.
GOAL - Wins the player that first occupy the opponent initial cells with his own stones.
An example

Black's turn. He can win by make the following L path (thru cells [1], [2] and [3]).

If it was White's turn, he could move a2 to a1 since that would not be a L move (after the 90 turn, the stone must at least move one cell). He could try to prevent black's winning by moving a2-c2-c4. Then Black could move a3-c3-c2. White must move c4-c3-a3 (the other two white stones cannot move anymore), and Black wins with c2-b3-c4. 

This game is presented at 100 Strategic Games for Pen and Paper by Walter Joris.