"There are eleven players a side in the game of Quodpot. They throw the Quod, or modified Quaffle, from team member to member, attempting to get it into the "pot" at the end of the pitch before it explodes. Any player in possession of the Quod when it explodes must leave the pitch. Once the Quod is safely in the "pot" (a small cauldron containing a solution which will prevent the Quod exploding), the scorer's team is awarded a point and a new Quod is brought on to the pitch."
-- Quidditch Through the Ages (QA8)
Effect: Used in the pots serving as goals in the game of Quodpot to keep the Quod from exploding (QA8).
History and Notes
Quodpot is an American version of Quidditch invented by Abraham Peasegood (QA8).
From the Web
Pottermore feature: Games and Pastimes in the Wizarding World
Harry Potter Wiki: Quodpot solution