This tutorial aims to give a broad overview of state of the art in agent-mediated negotiation. The tutorial will focus on the game-theoretic foundations of electronic negotiations. We review the main concepts from both cooperative and competitive bargaining theory, such as Pareto optimality, the Pareto-efficient frontier as well as utilitarian, Nash and Kalai-Smorodinsky (egalitarian) solution concepts. We discuss and compare games with complete and with incomplete information. Next, we exemplify these concepts through some well-known sequential bargaining games, such as the ultimatum game. A particular emphasis will be placed on multi-issue (or multi-attribute) negotiation – a research area that has received significant attention in recent years from the multi-agent community. We discuss some of the challenges that arise in modeling negotiations over multiple issues, especially when no information (or only incomplete information) is available about the preferences of the negotiation partner(s), as well as some of the heuristics employed in AI and machine learning research to solve this problem. The second part of the tutorial focuses on multi-issue negotiations which may have realistic limitations like real time constraints, computational tractablility, private information issues, online negotiations, etc.