They must also promise another asset to ensure that the endorsement has consideration and is therefore a valid contract. Talk to a lawyer if you are not sure that consideration is a prerequisite, as this depends on both national and contract law. Night rabies is not applicable unless it complies with the existing contractual conditions. Many contracts provide for certain circumstances in which the terms may be changed. Check the original contract and look for conditions that prohibit night rage, allow one party to change the contract without the agreement of the other party, or other requirements for night rage. Night rage is often used in the real estate market. .