Copyright (c) 1976 John Conway

This game is played on the following 1xn square board (say 1x12):

SETUP - One player drops a number of stones into empty cells The other player decides who starts.
STONE - A stone move by sliding to the left into an empty cell.
Stones may jump over other stones.
MOVE - On each turn, each player moves one stone.
GOAL - Loses the player that cannot make a valid move (i.e., all stones are lined up to the left).
An example

The next player wins, by moving to right stone into the 2nd left cell. The following player cannot make a valid move and loses.

This is a NIM-like game.