Gharar

Gharar is an element of deception either through ignorance of an essential element of the goods, the price, or through faulty description of the goods, in which one or both parties stand to be deceived.  E.g. gambling is a form of Gharar because the gambler is ignorant of the result of the gamble.  Gharar is divided into three types, namely gharar fahish (excessive), which vitiates the transaction, gharar yasir (minor) which is tolerated and gharar mutawassit (moderate) which falls between the other two categories. Any transaction can be classified as forbidden activity because of excessive gharar.