Capping a slot machine means locking the machine down temporarily. It only happens at land-based casinos where the players get to take a break without another player coming along and stealing the progressive jackpot.
You might want to cap the slot you’re playing for a myriad of reasons. You might be hungry and want to take a stroll to the restaurant. You might want to empty your bladder real quick. You might want to go get a drink from the bar.
Whatever the case is, you can simply ask a casino employee to cap the machine for you. Of course, there is a time limit to how long you can keep a machine capped. The attendee will most likely ask you when you’ll be back. And if you don’t come back for whatever reason, he or she will uncap the machine for the next player.
Keep in mind that all casinos may not be open to the idea of capping a slot machine. It’s our own fault. Many players have tried to exploit the capping mechanism. It may also depend on how you talk to the employee and whether they believe your reasoning or not.