Chains is played on a square grid at least 5x5 in size. Players take turns entering their symbols (e.g. X and O) in empty spaces. If the grid side is an odd number then one space will be left empty so each player has the same number of turns. After the grid is complete each player scores in two ways. They score one point for each of their symbols in their longest chain of symbols (i.e. the longest path of their symbols that can be traced without backtracking). They also score one point for each adjacent pair of their symbols. A symbol can belong to more than one pair and to pairs as well as the longest chain. Diagonal adjacency doesn't count for anything.