This book presents criteria and recommendations for successful negotiations. The System of Negotiations, which was developed on a scientific basis for this purpose, clearly illustrates the most important steps, tools and applications. By using game theory and behavioral economics, the success of negotiations in purchasing can be systematically maximized. At the same time, transparency and fairness offer a high level of acceptance among negotiating partners. To this end, numerous practical examples are used to show how contracts can be awarded in the event of competition between suppliers, and how various auction formats and differentiated communication can be used to achieve optimal savings potential. Also for situations where the supplier is a monopolist, ways are described to avoid being at the mercy of pricing power.