Limitations on assignment
1.  Contract provisions
a.  Prohibition –“don’t do it”, “rights are not assignable”
i.  Takes away the right to assign, but not the power to                         assign
ii.  Assignor is liable for breach of contract
iii.  Assignee can enforce the assignment so long as he did                         not know of the prohibition
b.  Invalidation – “if you do it, it will not be recognized”, “all                     assignments of rights under this K are void”
i.  Takes away the right to assign and the power to assign
ii.  Breach by the assignor if assigned
iii.  No K rights in assignee
a.  Common law bars the assignment that substantially changes the                     duties of the obligor
b.  Assignment of the right to payment is always ok