This game, introduced by the Ideal Toy Company in 1967, is played by pulling sticks that are holding a group of marbles in place one-by-one, while trying to not let the marbles fall down.
While KerPlunk can be entertaining, according to the Occupational Therapy Association, it can also build coordination, visual perception and problem solving skills for children.
"Ker-plunk! is the game where you take your pick and pull a stick. If all the marbles fall, you lose it all! You're only sunk if they go... Ker-plunk!"
Nowadays it's made by Milton Bradley in the UK and Mattel in the US.
What's it worth? Take a look at this Kerplunk price guide: sold listings for a value indication.