A Novation Assignment Agreement is a legal contract that transfers the contractual obligations of one party (assignor) to a third party (assignee). Novation: What's the difference?An assignment and assumption agreement transfers one party's rights and obligations to a third party. This Standard Document contains provisions to incorporate an assumption of the delegated obligations and an optional novation into the assignment agreement. An assignment and assumption of lease is a legal real estate document that allows one party to transfer rights and obligations of a lease to another party. This letter serves as an assignment, assumption and novation agreement.