| A | B |
| accord | agreement to contract to change obligation |
| alteration | material change to a contract |
| anticipatory breach | notifying before scheduled performance of refusal to perform |
| assignment | parties transfer contractual rights to another |
| breach of contract | failure to perform legal duty or agreement |
| default | failure to perform legal duty or agreement |
| delegation of duties | turning over contractual duties to another |
| major breach | a breach that does not alter the other party's duty to perform |
| novation | contractual party's release of other party for substitute party |
| substitution | replacement of original with another |
| substantial performance | performance of all but a minor contractual duty |
| tender | offer to perform an obligation |