Earlier quoted context omitted.
Weighted dice. Go back a century and it's much easier to ban gambling using dice than it is to ensure that the games are fair.
Or it was a [poor] way to try and ban certain types of gambling while allowing others.
Same thing, really. Dice games tended to erupt into violence amid accusations of dice being weighted; there was no practical way to sure that the dice weren't weighted, but the state had an interest in preventing violence; so the solution was to ban those games while allowing other forms of gambling which were less likely to become violent.