Video games demand is constantly increasing, which requires the costly production of large amounts of content. Towards this challenge, researchers have developed Search-Based Procedural Content Generation (SBPCG), that is, the (semi-)automated creation of content through search algorithms. This paper surveys the current state of SBPCG, reporting new work in the field from the last decade and identifying open research challenges. The results of the survey lead to recommendations for practitioners and to the identification of several potential future research lines for SBPCG.