Pull-tabs are gambling tickets used in games also known as Break-Opens, Nevada Tickets, or Instant Bingo, where players open perforated windows on multi-layered paper to reveal winning symbol combinations. Unlike slot machines, which operate on random probability, pull-tabs are unique because each "deal" has a predetermined quantity of tickets (ranging from 5,000 to 50,000) and a fixed number of winning chances, meaning every losing ticket brings a player closer to a winner. Typically sold for 25¢ to $5, these games offer prizes up to $5,000, and players can often see through transparent boxes how many tickets remain and check a tally sheet to know how many major winners are still available. The games have evolved into electronic forms, with the first patent filed in November 1990, and the latest version authorized in Minnesota in 2012, which uses handheld tablet-like devices with touch screens for state-licensed charitable organizations. All electronic devices are controlled and monitored from a central computer system, maintaining the same finite-probability basis as their paper counterparts.