Gambling is illegal in Japan.
A gambling hit can be multiple things. One type of gambling in Japan that was popular in the day involved betting these awesome wooden block things. You'd gamble by hitting them down on the ground, making a nice thunk sound. Another way to think about it is like blackjack. You want a card? You hit! Either way, it's gambling.
The reading is weird on this one, but gambling is weird, I guess. はく goes to ばく, maybe because you're playing some gambling backgammon. The ち can be cheating, where you cheat at this gambling backgammon. So, you're backgammon cheating (ばくち), you big cheater.