Time was when youngsters would be picking these little brown nuts up by the bagful and threading a string through them and then bashing them to bits against their opponent's to see which was the hardest. (If none were lying on the ground it was considered perfectly rational to lob a big long branch up into the tree to knock a few down. Just watch out for the returning branch! I speak from experience.) Yup, an absolutely pointless pastime but one involving complex rules, a modicum of skill in aiming the damn thing and no end of skulduggery getting them as hard a nails using various treatments, soaking in vinegar was supposed to toughen 'em up. Of course you could just cheat and keep one from the year before, but that was a knavish trick.
The game, if you can call it that, seems to be losing popularity. You simply don't see children picking up conkers any more. I've even heard of some schools banning the game on health and safety grounds! For heaven's sake a knock on the knuckles from a errant conker is all part of life's tough journey.
Now these seeds of the Horse chestnut just lie on the pavement unloved and unwanted. I'm told you can use them to scare spiders away but one correspondent in the Times reported that his pile of conkers designed for this purpose was covered in cobwebs. Still if the spiders insist on coming in you could, I suppose, whack them on the head with a conker.
As I say the game is mainly for children, no-one I knew ever played it when they reached the grand old age of twelve. It seems however that there is a World Conker Championship (surely not) held in Aston in Northamptonshire every October. Now that is bonkers!