a contract may contain a non-assignment clause, which prohibits the assignment of specific rights and some various rights, or of the entire contract, to another. however, such a clause does not necessarily destroy the power of either party to make an assignment. instead, it merely gives the other party the ability to sue for breach of contract if such an assignment is made. however, an assignment of a contract containing such a clause will be ineffective if the assignee "knows" of the non-assignment clause, or if the non-assignment clause specifies that "all assignments are void".