Lightly butter a 13x9 inch baking dish.

Melt butter in large soup pot. Stir in Caramels and sweetened condensed milk. Continue cooking, over medium heat, until Caramels are melted. Add marshmallows and cook till melted, stirring occasionally.

Remove from heat. Mix in Rice Krispies, stirring till well combined. Pour into prepared pan. Using buttered hands, press mixture to form to pan.

Cool, then cut into bars