Separate the room in 2: one side is the soup and the other side is the birthright.
Let the children choose which side they wish to be on.
Once the children have chosen their side, the host throws a coin and shouts soup or birthright (if it’s a coin toss). If it’s soup, all players on the side of birthright will sit down and are eliminated. Those who were on the soup side continue the game and again choose which side they wish to be on (soup or birthright).
The host throws the coin again…
The game continues until all the children are eliminated or until there are the number of children left that you have determined at the beginning: the last 3 are the winners or the last 5 are the winners.