World conker champion found with steel chestnut, cleared of cheating

Is this game well-known enough in Britain and Ireland that readers will know what on earth is being alleged just from reading this article? Or are you expected to have to google it?

Apparently it’s a game where you take turns swinging a chestnut on a string and trying to hit the opponent’s chestnut and break it. Yes, I can see how a steel fake chestnut would be an advantage here, though I’m amazed it wouldn’t be instantly obvious to even a casual observer that the look and sound were wrong. So maybe I’m still missing something.

Innate knowledge to Brits, similar to knowing a swan might break your arm

Lol, I don’t understand what THAT means! A swan might break your arm?!?

I emigrated to Britain. These sorts of things mystified me for the longest time.

Yes. Picture some British parents and their child on a walk near a pond, river, canal or whatever. The child sees a swan. The parents will say something like "don't get too close dear, it could break your arm".

Swans are aggressive so it's probably not terrible advice, but not because they go around breaking people's arms specifically.