Can I sue for a gift that I never got?

[tranquility]

In promissory estoppel, you can sue for the amount you are harmed from the reliance, in the concept of the charitable subscription is a little different. (Although promissory estoppel did probably grow from it.)

In some instances, we may have real consideration. A promise by the charity the gift would be used in a certain way or to have some memorial which bears the promisor's name.

However, the courts tend to find some type of consideration in the charitable arena. Even if they have to make it up, in order to make the benefit of the bargain the damages.

Legal Principles
Restatement (Second) of Contracts §90 – Promise Reasonably Inducing Action or Forbearance

(1) A promise which the promisor should reasonably expect to induce action or forbearance on the part of the promisee or a third person and which does induce such action or forbearance is binding if injustice can be avoided only by enforcement of the promise. The remedy granted for breach may be limited as justice requires.
(2) A charitable subscription or a marriage settlement is binding under Subsection (1) without proof that the promise induced action or forbearance.