Doubles/Multiplier

Doubles/Multiplier
This is a secret rule, in which when two cards of the same value are placed on top of one another, one must knock on the table twice and say "Doubles". Some variations of this rule will have a multiplier for Triples and so on, with another knock will be added, and you will say the number of cards such as "Triples!" and "Quadruples!". This number can get higher when played with a combined deck, which is common in some circumstances, especially when many people are playing.