<![CDATA[Progress in artificial intelligence (AI) and digital learning technology has moved quickly, opening fresh possibilities for strengthening English language instruction, particularly within English for Specific Purposes (ESP) settings. Even so, a substantial number of ESP learners continue to struggle in building English proficiency and higher-order thinking abilities, largely because interactive learning resources remain limited and conventional teaching methods still dominate. This study set out to design and assess an AI-gamified interactive HOTS e-book intended to strengthen ESP students' critical thinking. A Research and Development (R&D) approach was adopted, guided by the Decide, Design, Develop, and Evaluate (DDD-E) model. Participants consisted of ESP students at Universitas Muhammadiyah Mamuju. Data were gathered using expert validation sheets, student practicality questionnaires, and effectiveness tests. Findings showed that the developed AI-gamified interactive HOTS e-book fell into the very valid category based on expert assessment, with an overall mean score of 3.85. Student responses pointed to a highly practical product, averaging 3.69. The effectiveness test further revealed a marked gain in students' learning outcomes, with mean scores rising from 58.67 at pre-test to 87.53 at post-test and an N-gain score of 0.717, placed in the high-improvement category. The study concludes that the AI-gamified interactive HOTS e-book stands as a valid, practical, and effective digital learning medium for advancing ESP students' critical thinking and their English learning progress.]]>
