Assignment of rights allowed when:
Present intent to transfer immediately, no consideration required, but that supported by considereation is irrevocable.
Must not materially increase duty or risk of obligor or reduce his chance of obtaining performance.
Even if contract prohibits against assignement, assignment still permissible.
NY rule: irrevocable transfer of assignor's rights by assignment need not be supported by consideration if it is in writing and signed by assignor.