In Marriage Royals a round cannot end until at least one player has a marriage. Each marriage partner adds the positive scores of the other to their own score. Marriages can be converted by "ransoming" one spouse for a card of the same denomination. This makes for some interesting maneuvering before the game ends.
Marriage Royals was developed by Devin Carroll in 2013. The rules to Royals can be found on the Official Royals Card Game website.