Mutuality

Reciprocation; interchange, An acting by each of two parties; an acting in return. In every agreement the parties must, as regards the principal or essential part of the transaction, intend the same thing; i. e., each must know what the other is to do. This is called "mutuality of assent." Chit. Co.nt.

13.

In a simple contract arising from agreement, it is sometimes the essence of the transaction that each party should be bound to do something under it. This requirement is calied "mutuality." Sweet. Mutuality of a contract means an obligation on each to do, or permit to be done, something in consideration or the act or promise of the other.

Spear v. Orendorf, 26 Md. 37.