The Colour Stack Challenge Game is a head-to-head puzzle race to sort the mixed up coloured rings into stacks of the same colour as quickly as possible before your opponent. Choose from 50 Easy and Hard challenge cards and race your opponent or test yourself against the clock.One player draws a Challenge Card for both players to complete, showing how the rings should be arranged on the Stack Rack to begin. On the count of 3, both players must race to organise their mixed-up stacks into columns of single colours. Players can move only one ring at a time and may place it on an empty pole or on another ring of the same colour. Each pole can hold up to 10 rings, and players can sort the colours in any order they like, as long as they start and finish with two empty poles on the rack.