Caro (or Gomoku) is an abstract strategy board game and is also called Five in a row. It is traditionally played with go pieces (black and white stones) on a go board (19x19 intersections). This game is known in serveral countries under different names.
In this game, there are two symbols: O and X. Players alternate in placing their symbols on an empty intersections. The winner is the first player to get unbroken row of five cells horizontally, vertically, or diagonally.