The genre of educational adventure games is a common and successful choice in game-based learning. The games combine captivating narratives that motivate players to continue playing with game mechanics that are conductive to learning: the gameplay is slow-paced, allowing players to learn at their own pace, and focused on puzzles that can be infused with educational content. While educational adventure games are well suited for learning in most settings, their creation is often challenging for non-technical experts. Furthermore, existing game editors do not account specifically for adaptive adventure games, which can maximize the learning effectiveness of the games by catering to the players' needs. To address these two challenges, we present a game model for this genre and use this model to build an authoring tool that lowers the threshold for adventure game creation and supports adaptive educational games. The implementation of this concept was evaluated in several studies.