vi)         Agreements creating an interest opposed to duty:
If a person enters into a contract with a public servant, which to knowledge might cast upon the public service obligations inconsistent with the public duty, the agreement is void.

Case-
a)    An agreement is not to report in newspaper the activities of a public personality is a void agreement. Similarly, if a lawyer wants to create an interest, which will encourage him to perform his duties indifferently, the agreement shall be void. Nevile v. Dominion of Canada News Co(1915)  

b)    An agreement by an agent with a third party whereby he would be enabled to make secret profits is illegal and void, as it tends to create a conflict between interest and duty.

vii)    Agreement opposed to parental duty:
The authority of a father over children and a guardian of a ward is to be exercised in the interest of the children and the ward respectively. The authority of a father cannot be alienated irrevocably and any agreement purporting to do so is void.

Case-
a)    Where the adopting father promises money to the natural father in return for adoption of the latter’s son, such promise is void. Sitaram v.Harihur(1915)  .

b)    The father of two minor sons agreed to transfer their guardianship to Mrs. Annie Besant, on an irrevocable basis. Subsequently he wanted to rescind the agreement. Held their guardianship cannot be permanently alienated. So he got back their custody. Giddu Narayanish vs Mrs. Annie Besant.  

viii)    Marriage brokerage agreement:
According to English Law an agreement to pay brokerage to a person for negotiating a marriage, is void because it is against public policy. The principal underlying this rule is that marriages should take place according to the free choice of parties and such choice should not be interfered with by third parties acting as brokers.

Bakshi vs Nadu Das (1902).. (i) Gifts made to the groom or the bride are valid transactions. (ii) Gifts made can be claimed back if the match fails.(iii) A promise to give a marriage in ret6urn for money is a void promise. (iv) A promise to remunerate the broker is void.  

Case
a)    An agreement to pay money to the parent or guardian of a minor in consideration of his consenting to give the minor in marriage is void as being opposed to the public policy. Dholidas vs Furchand, (1897) 22 Bom. 658.  
b)    An agreement to pay a penalty in case a minor daughter is not given in marriage to a particular person is void. Devarayan vs Muthuvaman, (1914) 37 Mad. 393.  

ix)    Agreement tending to create monopolies in trade:
Agreements having for their object, the creation of monopolies are void as opposed to the public policy. Somu Pillai vs MC Mayaveran, (1905) 28 Mad. 520.  

x)    Agreement to defraud revenue authority:
Agreements to defraud revenue authorities are void and illegal.

Case
An agreement by which an employee was to get, in addition to salary, an expense allowance grossly in excess of the expenses actually incurred by him, was held illegal because the provision as to expenses was contrary to public policy being merely a device to defraud the Income Tax authorities. Napeier vs National Business Agency Ltd. (1951). 2 All. ER. 264.  

xi)    Agreement to give evidence:
Agreements whereby money is given to induce persons to give evidences in a civil port are void because everyone is expected to perform his legal duty. Adhiraja Shatty vs Vittil Bhatta AIR (1914). Mad. 366  

xii)    Agreement against personal freedom:
Agreement which unduly restrict personal freedom have been held to be void and illegal as being against public policy.
            
Case
When a debtor promises not to change his residence till repayment of a loan is complete, such promise is void.  Harwood vs Millers Timber & Trading Co. (1917), 1KB 305.   

xiii)    Agreement opposed to marital duties:
Agreement, which interferes with the performance of marital duties, is void as being against public policy.
        
Case
a)    An agreement to pay money so that a party to a marriage may be helped in obtaining a divorce shall be against public policy and void. Roshan vs Mohammed (1887)  

b)    An agreement that the husband will always stay at the mother in law’s house and that the wife would never leave her parental house is void. Tikyat vs Monohar 28 Cal. 751.