The second set is for an unlawful object, namely, that B may use the house as a gambling house, and is a void agreement.

Alternative promise, one branch being illegal Alternative promise, one branch being illegal.—In the case of an alternative promise, one branch of which is legal and the other illegal, the legal branch alone can be enforced.

Illustration. A and B agree that A shall pay B 1,000 rupees, for which B shall afterwards deliver to A either rice or smuggled opium.