Slot Tutorials

Slot Vocabulary: Candle

Slot machine candles on top of machine
Written by Joshua

If you’ve ever noticed the lights atop a slot machine, and seen them blinking, you’ve just noticed the candle, one of the more steady slot machine features across its modern history.

A candle is a bit outmoded theoretically thanks to modern advances in technology, and nowadays at many casinos will get an alert on a smartphone as to what and where something is needed. Despite that, many casino floor staff still respond when they see certain signals from them.

Since there is a standard for how a candle’s lights operates, staff is still trained to know to look for those visual signals. While us players will be looking down at the games and figuring out what we want to play, the attendants will regularly look up and scan for those candles, which ones are lit up, and what signals they are sending.

The candle has two segments to it, a top and bottom light. Which light(s) are activated (whether solid or blinking at some pace) can tell a slot attendant at a glance what’s going on with a machine. Some examples include:

  • Solid top light: Someone hit the service button on the machine. That’s why attendants will come over and ask you if you need help when that light is on and solid – that’s their bat signal to come check.
  • Lower light blinking: A machine’s door has recently been opened. You’ll see this a lot when the cash boxes are swapped out overnight.
  • Both lights blinking rapidly: The machine has been taken out of service.
  • Both lights blinking slowly: The player has hit a jackpot and is waiting to get paid!

Candles can send other messages too, like when a machine is low or out of paper, and for coin machines when it needs a coin refill or is full.

The upper half of a candle is always white, but the lower half will have a color based on a machine’s lowest denomination. The colors include:

  • White: Penny
  • Red: Nickel
  • Yellow: Quarter
  • Gold or Orange: Fifty Cents
  • Blue: One Dollar

As a player, if you’re looking for certain denominations, getting to know these color codings can help you eyeball the casino floor without having to get close to a given machine to know its denomination starting point. However, with many machines being multi-denomination today, you may still need to check to see if it has other denominations.

As such, the candle is a simple, yet effective communication machines through visuals on what can be a noisy, busy casino floor. And even though modern technology could make a candle completely obsolete, for now the candle survives as a silent communication device for the casino staff.

About the author


My name is Joshua, and I’m a slot enthusiast who works in tech as a marketer by day, and dabbles in casinos periodically during off-times. Know Your Slots will reflect my interests in understanding the various ways you can play slots, travel, casino promotions and how you can get the most out of your casino visits.

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