单方允诺

英美法系通过合同法中的约因理论和允诺禁反言原则，合理地解释了单方允诺得以产生合同法之拘束力的原因。

The contract law in common law system indicates that unilateral promise can produce the effect of contract because of the theory of consideration and the principle of promissory estoppel .

假一罚十是商家的单方允诺，属于单方法律行为，它以买卖合同为生效条件，属于附条件的单方法律行为。

" Decuple Penalty for Fake " is the company 's unilateral promise which belong to the unilateral legal act , meanwhile , It regards business contract as to effective term , belonging to the unilateral legal act attached conditions .

通过比较研究和实证分析，笔者认为，以立法的方式确认单方允诺系意定之债的发生原因之一确有必要，并进一步确立了这一制度得以发生法律效力的构成要件。

Through comparative research and empirical analysis , the author believes that it is necessary for the law to confirm that unilateral promise is one of the reasons that produce obligation . After that , the author analyses the constructive elements of the unilateral promise .