Section — Prümmer, Manuale Theologiae Moralis
§ 2. On Wagering
315. Notion. A wager203 is "a contract by which two or more persons contending concerning the truth of some matter set a prize for him who shall have attained the truth."204
From this definition it follows that a wager is a bilateral onerous contract. Sometimes, however, only one person making the wager assumes an obligation upon himself;205 e.g., I wager that I shall complete this course in the space of one hour; otherwise I shall give ten francs for the poor. In this case the wager is rather a certain conventional penalty which someone, for the most part from vainglory, imposes upon himself.
Lawfulness of wagering. Wagers, considered according to natural law, are lawful, provided they are made: a) from an honorable end, e.g., for the sake of recreation, for stimulating one's powers, for investigating the truth better, etc.; b) concerning a due object, namely, a lawful matter doubtful on both sides. Since, however, grave and frequent abuses occur in wagers in practice, several modern civil codes partially or totally prohibit and invalidate them.
It is evident of itself that a wager concerning an illicit matter, e.g., concerning committing a theft, drinking an excessive quantity of wine, an exorbitant prize, goods of which the person wagering does not have free disposition, etc., is sinful.206 Nevertheless, profit received from such a wager can be retained. For the same thing holds which was said above, n. 253, concerning profit received from a shameful contract. Under pain of excommunication (which, however, no longer exists today), Gregory XIV, in the constitution Cogit nos of March 21, 1591, prohibited wagers made upon the election of a future Roman Pontiff or of Cardinals.207 The object of the wager ought to be doubtful on each side, i.e., each person wagering ought to have doubt and not certainty concerning the event in dispute. Hence, more probably, a wager is invalid if one person wagering is certain concerning the matter in controversy, even though he has openly warned his adversary of his certainty.208 The reason is that in this contract of wagering there ought to be hope of gain. But if one is certain concerning the event, the other has no hope of gain, and consequently cannot reasonably stake anything for it.209
Civil codes commonly establish: a) that no obligation arises from wagers; yet also b) that he who has received some profit from a wager is not bound to restore it.210 These statutes, as just, seem to oblige in conscience. Hence, e.g., in Germany wagers (and the same holds for games) which are excessive and prodigal produce no obligation in conscience. Concerning the lawfulness of wagering, St. Alphonsus writes:211 "In the concrete (since, in my opinion, no indifferent action is given), I regularly judge that wagers of this kind are not excused from venial sin, because in them there is lacking the motive which renders lawful recreation honorable, as it is present in an honorable game. And St. Antoninus212 seems to understand it thus, calling such profit shameful, as serving no utility, but vanity and prodigality." This opinion indeed seems true if there is question of those who make wagers frequently and in grave matter; but if there is question of rare wagers of lesser price, they are indeed to be avoided by clerics and religious persons, since they furnish matter for contention, but they are not evil in themselves.
203 Wager (Wette, pari, betting).
204 Cf. Billuart, l.c. diss. 6, a. 5, § 5.
205 Unilateral wager (halbe Wette).
206 St. Alphonsus aptly observes (Theol. mor. l. 3, n. 870): "If the wager concerns a sin to be committed by some third person, it is lawful unless the person wagering desires the sin or gives assistance toward committing the sin.... But if the wager concerns a sin to be committed by one of the persons wagering, it will be lawful if you were to wager, e.g., that the other will commit the sin, because then the wager averts him from sin. It is otherwise if you were to wager that you would commit the sin, or that the other would not commit it; because then the wager would induce one to sin."
207 Cf. Moran, Theol. mor. I, 1187.
208 Cf., however, St. Alphonsus, l.c. n. 878ff.
209 Cf. Billuart, l.c.
210 German Civil Code § 762ff.; French Civil Code art. 1964ff.; Austrian Civil Code § 1271; Swiss Code of Obligations art. 513ff.; Italian Civil Code art. 1802. For Spanish law see Moran, l.c. 1184, and Larraga-Saralegui, Comentarios n. 826.
211 Theol. mor. l. 3, n. 869.
212 S. theol. P. 2, tit. 1, c. 23, § 9.