Game of Flags

Collect set of flags by calling out missing cards. If opponent has the card, he has to surrender it to the caller. Make sets of four to earn points. A special "crown card" can be used to substitute a missing card. The winner of the game is the player having the most sets at the end. As the game is pretty old (1896 on the box) some flags have changed since then. Seemingly a variant of The Game of Authors or Happy Families