Yale law professor Ian Ayres examines Allegheny College v. National Chautauqua County Bank, a foundational promissory estoppel case in his American Contract Law course. The case concerns a donor's pledge to a college and whether the school's actions in reliance on that pledge can substitute for traditional consideration when the donor's estate later refuses to pay. Ayres uses the case to illustrate how courts have stretched or reinterpreted the consideration doctrine to enforce charitable promises, walking through the reasoning judges use to find implied bargains in transactions that look like gratuitous donations. The lecture sits within a unit on consideration and its substitutes, part of a Coursera-linked series covering the doctrinal building blocks of contract formation. Ten minutes long, it is aimed at students working through case law method rather than general audiences, with case documents made available separately for follow-along reading.