Basically, courts will first look to see if there is an enforceable contract, either bilateral or unilateral. Failing that, the court might try to use a legal doctrine known as “promissory estoppel.” In layman’s language that means something like, “You made a promise and the other party relied on it. You received some benefit from your promise, so you should not be able to disavow it.”
The bottom line is that the legal system has a public policy preference of seeing that charitable pledges are fulfilled and will seek legal ways they can be enforced.
An estate planning attorney can guide you on donations you intend to make as part of your estate plan.
