What is Variable Rewards?
Spin-the-wheel prizes, mystery discounts, surprise match reveals, and randomized drops all pay out on an unpredictable schedule. It is the uncertainty of the reward, not its size, that keeps you pulling the lever.
Where it comes from
B.F. Skinner / operant conditioning (1950s)
How it hooks you
Exploits variable-ratio reinforcement, the most habit-forming reward schedule known: because you cannot predict which action will pay off, you keep repeating it far longer than a guaranteed reward would sustain.
How to resist it
Notice when an app turns a simple tap into a gamble, and set a hard limit on spins, swipes, or opens before you start.