 These options can be assessed in terms of what is known within contemporary decision theory as the Expected Value Principle (EVP). The EVP states that when one is faced with a choice among competing courses of action, one should choose whichever has the highest “expected value.” Expected value can be calculated by (a) multiplying the probability of a successful outcome by the value of that outcome; (b) multiplying the probability of an unsuccessful outcome by the cost of that outcome; and (c) taking the sum of the results of (a) and (b). In light of the EVP it can be rational to gamble on an improbable outcome given a sufficiently high potential payoff.