A balloon, a pump, and up to twenty-five pumps. Choose how fragile the balloon is, place your bet, and pump it up one push at a time: tap the balloon, the pump's gold handle, or Pump (it shows the chance the next pump holds). Every pump that holds raises the multiplier and swells the balloon; a pop ends the round and the bet is lost. Cash out whenever you like to take your bet times the multiplier.

A more fragile balloon means a steeper climb and a bigger chance of a pop. Every cash-out point returns the same 97% on average, however fragile the balloon or however many pumps you take. In Auto, pick how many pumps to take with the stepper on the stage (a dashed gold outline shows the size it reaches): every round pumps that far, then cashes out.

Each pump is decided from your own provably fair seed pair at the moment you pump, and never changes afterwards. After the round, or with New seeds, check every pump on the Provably fair page. A round left open is cashed out after ten minutes (one pump is taken for you if you hadn't taken any).