Study of Gharar (Aleatory Contract) and Feasibility of Its Effective Scale on Transactions in Islamic Jurisprudence

One of the factors in validity of deals is Gharar. Although all of the jurists consider Gharar as one of the factors effective regarding the validity of the contract but some of the contracts and deals can be considered valid with existence of Gharar and some may be considered invalid. This may be indicative that scale of Gharar may be an effective on the decree of the deals. With studying the saying of jurists we can conclude that they did not introduce the factors of the scale of Gharar. Some of the jurists say that custom is the deciding factor and others considers the severity as a factor but they don’t introduce a criterion to measure its severity. Its seems that leavimg it to custom or introducing a vauge criterion is not right and there should be a specified criterion. Based on reviewing the texts of Quran and Sunna, including the first and last verses of surah Muzamal as well as two Hadiths “one third and one third is a lot” and “the food of two is enough for three” it can be said that there is a measure and a rule between small and large Gharar affecting the validity and invalidity of a contract.