Quick answer: The player who draws a 5 becomes Thumb Master. When they put a thumb on the table, the last player to copy them drinks.
What Does 5 Mean in King's Cup?
The Thumb Master may trigger the challenge at any suitable moment. The role normally lasts until another 5 is drawn, when the new drawer takes over.
Common 5 House Rule
Some groups use “Guys” for 5. Thumb Master is a more inclusive option and works with every group.
House rules differ by group. Confirm the meaning before the first card is drawn, allow anyone to choose a non-alcoholic alternative, and never pressure a player to participate.
5 Rule FAQ
What is the 5 rule called in King's Cup?
The common 5 rule is called Thumb Master. House rules can vary, so agree on the meaning before play.