A party game intended for children.
The host 'hides' each Key Card in different locations around the area where the party is being held. The house or/and the garden would be most likely.
Each player is given a noun and must find that noun, written on the top left of one of the Key Cards. When found, it will say which noun to find next, and so on, until one player has found all 12 nouns in the correct order and written on their score-pad. That player is the winner.
The game is intended for up to 12 players but the publisher is rather optimistic in suggesting that if you buy extra cards (which he says are available at '12 for sixpence) then there is no reason why 500 people can't play. The publisher also suggests that you could play on a much wider area, with cards hidden so far apart, the players would need bicycles to get from one card to another.