Indian Contract Act, 1872
57. Reciprocal promise to do things
legal, and also other things illegal
Where persons reciprocally promise, firstly to do certain things
which are legal, and, secondly under specified circumstances, to do certain
other things which are illegal, the first set of promise is a contract, but the
second is a void agreement.
Illustration
A and B agree that A shall sell B a house for 10,000 rupees, but
that, if B uses it as
a gambling house, he shall pay A 50,000 rupees for it.
The first set of reciprocal promises, namely, to sell the house
and to pay 10,000 rupees for it, is a contract.
The second set is for an unlawful object, namely, the B may use
the house as a gambling house, and is a void agreement.