Well it is banned in schools. I'm not sure how many adults you believe actually play conkers, beyond a few nutters (sic), but its mainly been banned for the people that used to actually enjoy it, kids.

I do wonder if by banning it in schools it will get less and less common till it disappears. I suppose you predictably think that's nonsense.

But pedantry aside, its banned for the people who used to play it most and enjoy it, at the place they did just that.

You're downvoted because you're repeating unfounded tabloid rage-bait, hours after someone else posted a reliable source showing the opposite.

It is legal, but it also did get banned at my primary school. It continued to be played.

Conkers, bulldog, smoking behind the bike sheds (ok vaping these days), and porn (nowadays on screens rather than naughty magazines) ... a lot about British schools can be summed up in this quote:

“What exactly are you so happy about?' Harry asked her.'Oh Harry, don't you see?' Hermione breathed. 'If she could have done one thing to make absolutely sure that every single person in this school will read your interview, it was banning it!”

And they are generally banned in 1 school from one incident by one head trying to quell anger from parents.

The ban is generally lifted or just not enforced at all after a year or two.

For starters the playground monitors have more important stuff to do than remember the list of banned activities and try to enforce them.