Gait impairments negatively affect patients’ walking ability, without which they tend to suffer from a higher risk of falling and a lower quality of life. Repetitious training is necessary for patients to regain and maintain this ability. Compared with the conventional rehabilitation process, gamified rehabilitation has the potential to provide patients with a more engaging experience with helpful feedback. Extensive research has focused on the game design and rehabilitation technologies, however, less attention is paid to the personalization and adaptation within the game. In this thesis, we propose a generic adaptation scheme to support physiotherapists in conducting gait training. The scheme features the parameterized generation of the levels which can be steered dynamically based on the player model and therapists’ intervention. Two difficulty adjustment methods are adopted to provide patients with a personalized rehabilitation experience, which are (i) parameters- progression schemes manipulating multiple parameters in two systematic ways for creating levels with appropriate difficulty, and (ii) meaningful integration of separate rehabilitation exercises for providing variety in difficulty transition. Our goal is to assess how adaptive steering of a procedural game level generator can support a physiotherapist in achieving the desired rehabilitation goals. We implemented our design in a standalone prototype for conducting gait training in a three-dimensional overground body weight support system RYSEN. A set of mini-games was first developed through a mapping from therapy goals to the movement challenges in the gameplay. The difficulty adjustment methods were adopted in these games. Apart from the automatic game system, the prototype provides a real-time interface for therapists, which ensures their control of the rehabilitation session. Nine physiotherapists took part in the evaluation with their focus on the difficulty adjustment. The results show that our approach can assist physiotherapists in providing (i) helpful diversity for patients in everyday gait training, (ii) adequate challenge levels for a wider group of patients in various gait exercises, (iii) useful game controls to tailor the level of challenges for patients when necessary.