The developments of trade, economic liberalism, and, as a consequence, the appearance of economic powers, have introduced an intense difference between rich and poor classes. The opportunity of economic power bears the ability of exploiting poor classes. The need to food, treatment, and other essential needs like education and employment, forces weaker classes into contracts which in spite of being seemingly accompanied by free will, may look quite unequal and oppressive in the light of constraint.Imposing unequal economic contractual terms causes the fans of justice to react against unfairness. Although the constrained protection necessitates recognizing the contract he has entered into, if there is a suspicion of unfairness in a contract, the constrained protection can express itself in a different manner.The subjects of this article are the approaches of the constrained protection, equalizing the contract, and omitting unfair and oppressive terms. These are not indefensible in the thoughts of Muslim jurisprudents and the Iranian legislation system.