ecent successes aside, reinforcement learning (RL) still faces significant challenges in its application to the real-world robotics domain. Guiding the learning process with additional knowledge offers a potential solution, thus leveraging the strengths of data-and knowledge-driven approaches. However, this field of research encompasses several disciplines and hence would benefit from a structured overview.In this article, we propose a concept of guided RL that provides a systematic approach toward accelerating the training process and improving performance for real-world robotics settings. We introduce a taxonomy that structures guided RL approaches and shows how different sources of knowledge can be integrated into the learning pipeline in a practical way. Based on this, we describe available approaches in this field and quantitatively evaluate their specific impact in terms of efficiency, effectiveness, and sim-to-real transfer within the robotics domain. However, learning control policies in such a way naturally requires many interactions with the environment. This emphasizes the importance of both collecting highquality samples and exploring the search space in a sample-efficient manner. While directly learning on real robots is appealing, it comes along with substantial challenges, such as high sample cost, partial observability, and safety constraints [28]. Hence, simulators are often