Ultimatum game - Definition and Overview

The Ultimatum game is an experimental economics game in which two parties interact anonymously and only once, so reciprocation is not an issue. The first player proposes how to divide a sum of money with the second party. If the second player rejects this division, neither gets anything. Classical economics suggests that the first player should offer only a small amount and the second should accept it. But, in many cultures, people (except economics grad students) offer "fair" (50:50) splits, and offers of <20% are often rejected.