Combine rice, water and butter (optional) in a microwave-safe glass bowl.
Cover tightly with microwave-safe lid or plastic wrap and cook on HIGH using times below.
Reduce to MEDIUM (50%) for 10-15 minutes. Stir occasionally. Remove from microwave. Let stand covered 5 minutes or until water is absorbed. Fluff with fork and serve.
Microwave ovens vary. Cooking times are approximate. Adjust cooking time as needed.