Money tokens represent the most normal form of currency in Arkham, the dollar. They come in three denominations (Ones, Fives, and Tens) and are used at all shops in Arkham. They can also be spent at St. Mary's Hospital or Arkham Asylum to restore all your Stamina or Sanity, respectively.
Money tokens can be obtained through encounters at locations with the Money Icon, through the special encounters of the Bank of Arkham and the River Docks, through the special ability of Jenny Barnes, or through the effects of a Retainer or by being the Deputy of Arkham. Most Investigators also start with some money tokens.