A strategy game for 2 or more players. The objective of Chain Reaction is to take control of the board by eliminating your opponents' orbs. Players take it in turns to place their orbs in a cell. Once a cell has reached critical mass the orbs explode into the surrounding cells adding an extra orb and claiming the cell for the player. A player may only place their orbs in a blank cell or a cell that contains orbs of their own colour. As soon as a player looses all their orbs they are out of the game.