Order and Chaos
One player tries to get a line of five symbols and the other player tries to stop them.
The game is played on a 6 x 6 grid. The players play alternately, and on each turn a player can write either an 'X' or an 'O' in an empty square.
The first player takes the role of Order, and tries to complete a line of five 'X's or five 'O's in any direction. The other player, Chaos, tries to prevent this.
Order wins as soon as a line of five is completed. If the game reaches a point where no line of five is possible, Chaos wins.
Note that a row of six of the same symbol doesn't count as a win for Order.
The game was invented by game designer Stephen Sniderman, and he described it in Games magazine in 1981.