The Casino is an IBA official cocktail made with gin, maraschino liqueur, orange bitters and fresh lemon juice. The Casino, which appeared in Harry Craddock's 1930 Savoy Cocktail Book, falls into a category of cocktails called Daisies. Each of these drinks includes a spirit, citrus, and a flavored sweetener.
Add all ingredients to a cocktail shaker and shake until well chilled.
Strain into a glass and serve.