• Two generals planning to attack a city
  • Need to coordinate their attack
  • Coordinated attack: always succeeds
  • Uncoordinated attack: always fails
  • Faced with a dilemma if either original message, or its acknowledgment, is lost

Can be applied to, eg, an online transaction

  • If shop fulfills order without payment, they lose money
  • If shop collects payment without fulfillment, customer is irate

Can be further generalized to the Byzantine generals problem