Chess

I used to play quite a bit of chess, especially when I worked in schools; it used to attract a fair amount of 'ruffians' who were attracted to the game when they realised that a culture of high competition was involved.
This was win-win, as the school was delighted to see those pupils occupied, and I got to know them a bit better. 
Nowadays, it's usually against a computer, which is not quite the same.