After the contract becomes effective, a party shall not refuse to perform its obligation owning to any change in its name or change of its legal representative, person in charge, or undertake.

第七十六条合同生效后，当事人不得因姓名、名称的变更或者法定代表人、负责人、承办人的变动而不履行合同。

youdao

It is a matter of fact whether the parties enter into the contract, but it is a matter of law whether of not the contract is legal.

当事人是否签订合同是一个事实问题，但合同是否合法是一个法律问题。

youdao

Your handbook should contain a disclaimer clearly stating that it's not a legal contract (that way you're free to end someone's employment at will).

WSJ: How to Develop an Employee Handbook

The pledge is a moral commitment to give, not a legal contract, and it does not involve pooling money or supporting a particular set of causes or organizations.

FORBES: Ten More Tycoons Sign Buffett And Gates Giving Pledge: Dalio, Kinder, DeJoria

The site says the pledge is a "moral commitment" not a "legal contract".

BBC: US billionaires pledge 50% of their wealth to charity