The present volume of Springer s Lecture Notes in Arti cial Intelligence" - cuses on the challenge of balancing between the two extremes of pure reactivity and in-depth social deliberation in the context of multi-agent systems. Finding a balance between these two extremes will lead to an overall behavior of the individual agents and of the multi-agent system that meets the demands of the environment but also the demand for high-quality problem solving results. This book collects selected and revised papers from Balancing Reactivity and Social Deliberation in Multi-Agent Systems"{aworkshop...