Bargaining is about splitting a prize when everyone has to agree—two roommates dividing the biggest bedroom, a buyer and seller haggling over a price, or two companies sharing a contract. This chapter looks at two powerful ways to think about that problem: what a fair deal should look like (the axiomatic approach), and what deal self-interested players actually reach through offers and counteroffers (the strategic approach). By the end you’ll see why patience matters, how a handful of simple rules pin down “fairness,” and how a single number—bargaining power—determines who gets the bigger slice.