Four kinds of luck can be defined --- one that is pure "blind" luck, and three others that are influenced to some degree by certain behavioral characteristics. The term, altamirage is introduced to call attention to that special personal quality by which good luck is prompted as a result of personally distinctive actions (Chance IV). In contrast, serendipity involves finding valuable things as a result of happy accidents (Chance I), general exploratory behaviour (Chance II), or saga-city (Chance III). The most novel scientific discoveries occur when several varities of chance coincide.