Conkers

In Autumn in England, kids like to play a game called “Conkers”. A conker is another name for “horse chestnut”. In Britain we have to be careful when picking wild chestnuts to eat, because the very similar-looking horse chestnut is inedible. It’s only use is the game of conkers.
Kids select a suitably strong-looking conker, cut a hole through the centre using a corkscrew, thread a piece of string through it, tie a knot in the end and hold the string at the other end. They then use their conker to try to destroy their opponent’s conker, taking turns to swing. It’s best to see this video to understand it. I think nowadays schools forbid students from playing this because of the risk of injury. In my school days nobody cared at all about health and safety!
Like all things that are silly, there is actually a world championships, played by adults!

Here is a couple from London explaining the game that they haven’t played for over 40 years! The intro is long and boring so start at 3:30.