A slot machine is about intermittent variable reward, one of the most addictive systems in life where you may or may not win something so you feel compelled to continue trying. In what ways are you continuing to focus on something because there is a very slight chance of a big payoff? This dream may be pointing to a way in which you are tied to the habit of hope at the detriment of other aspects of your life. Of course, some gambles do pay off, so such an image in a dream may also be asking you to take a risk.
[1]Whether you played them, watched others playing, won, lost, or broke even, dreaming of slot machines is a warning to conserve your resources (either mental, emotional or financial) because you are likely to have some unexpected demands on them in the near future.
[2]1. Willingness to take a chance on something or someone.
2. Engaging in potentially self-destructive behavior.
[3]See Also: Gamble.
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