Not for the faint-hearted, this game is best played out of doors when clothes don't really matter! It works with mixed family age-groups if everyone who takes part is a good sport, and will cause much hilarity..
You will need:
Small cards with numbers written on them, from 1 to x, x being the total number of players. For 10 players, you need the numbers 1-10; for 14 players, the numbers 1 to 14, and so on. Put the cards in a hat or bag.
A small container for water. Choose an appropriate size for the age of your players, the location, the weather etc. A small plastic tumbler usually works well.
A large container of warm water, such as a bucket or baby bath.
How to play:
Choose one player to start. He picks a number out of the bag without letting anyone else (but you) see it, and remembers that number. He then fills up the small container with warm water and stands in the centre of the other players, who form a circle around him, but not too close. You will have to establish the correct distance!
The player in the centre faces each player in turn. Each player chooses - and says loudly - a number between 1 and x. Each player must choose a different number. As soon as somebody chooses 3, the child in the centre throws the container of water at them! No matter how often this is done, it still comes as a bit of a shock and children love it.
If you get all around the circle and all the players have chosen a number but NOT the correct one, the child in the centre has to throw the water over himself!