Summary: The paper relates to construction of computer based systems for decision support in negotiations. A special case of distributed decision making ‒ a class of bargaining situations is considered. DSS (decision support systems) utilizing mathematical model of decision situation can serve as a tool supporting unilateral and multilateral analysis made by negotiating sides (players). A problem of players’ manipulations is discussed. What does it mean fairness? How can players manipulate using DSS? Can we minimize the players’ manipulations applying game theoretical solution concepts in DSS? How can interactive procedures be constructed? This sort of questions is discussed in the paper.