In a saucepan over low heat, melt the peanut butter and butter together, stirring frequently to achieve a smooth mixture.
Combine the crisp rice cereal and confectioners' sugar in a large mixing bowl, ensuring an even blend. Pour the melted peanut butter mixture over the dry ingredients and stir thoroughly. The mixture will appear crumbly but will easily form into balls.
Shape the mixture into 1-inch balls and arrange them on parchment-lined baking sheets. Cover the sheets with plastic wrap and refrigerate for at least 3 hours or overnight until firm.
Melt the semisweet chocolate chips using a double boiler over low heat, stirring continuously to prevent burning.
Dip each chilled peanut butter ball into the melted chocolate, using two forks to coat it evenly. Allow excess chocolate to drip back into the bowl, then place the coated balls on a wire rack set over parchment paper.
Repeat the dipping process for all balls. Refrigerate the chocolate-coated balls until the chocolate has set completely.