This case study explores the legal principles of contract formation and promissory estoppel in the context of employment law. It examines the scenario of Frank, who advertised his car for sale, and the various offers he received. It also analyzes the situation of Renee, an employee who was promised a salary increase by her employer, but the promise was not fulfilled. The analysis delves into the elements of a valid contract, the concept of invitation to treat, and the doctrine of promissory estoppel, highlighting the legal implications of these principles in real-world scenarios.