This study was conducted with the aim of improving students' achievement motivation through the implementation of the Game-Based Learning model using Zep Quiz at MAN 1 Tuban. This study was conducted using a classroom action research method, namely the Kemmis and McTaggart model, which was implemented through two cycles, each cycle including the planning stage, action implementation, observation, and reflection. The research subjects were 32 students. Data were collected through observation, a Likert scale achievement motivation questionnaire, and documentation. Data analysis was carried out descriptively, qualitatively, and quantitatively. From the analysis, the results showed that in cycle I, the average student achievement motivation reached 55% with a learning completeness of 78.13%. After corrective actions were taken in cycle II, the average achievement motivation increased to 78% and the learning completeness reached 100%. This increase was supported by increased student activity, courage to face challenges, learning responsibility, and the ability to respond to feedback during learning. The conclusion of this study shows that the implementation of Game-Based Learning assisted by Zep Quiz is effective in improving achievement motivation and learning outcomes of grade XI students. Further research is recommended to examine the impact of Zep Quiz on other variables, such as critical thinking skills and collaborative learning. Abstrak Penelitian ini bertujuan untuk meningkatkan motivasi berprestasi siswa melalui penerapan model pembelajaran berbasis permainan (Game-Based Learning) dengan memanfaatkan Zep Quiz di MAN 1 Tuban. Metode yang digunakan dalam penelitian ini adalah penelitian tindakan kelas., yaitu model Kemmis dan McTaggart, yang diterapkan melalui dua siklus, masing-masing siklus meliputi tahap perencanaan, pelaksanaan tindakan, observasi, dan refleksi. Subjek penelitian adalah 32 siswa. Data dikumpulkan melalui observasi, angket motivasi berprestasi skala Likert, dan dokumentasi. Analisis data dalam penelitian ini dilakukan secara kualitatif, dan juga kuantitatif. Dari analisis, hasil menunjukkan bahwa pada siklus I, rata-rata motivasi berprestasi siswa mencapai 55% dengan kelengkapan pembelajaran sebesar 78,13%. Setelah dilakukan tindakan korektif pada siklus II, rata-rata motivasi berprestasi meningkat menjadi 78% dan kelengkapan pembelajaran mencapai 100%. Peningkatan ini didukung oleh peningkatan keaktifan siswa, keberanian menghadapi tantangan, tanggung jawab belajar, dan kemampuan memberikan umpan balik selama pembelajaran. Kesimpulan dari penelitian ini menunjukkan bahwa penerapan Game Based Learning yang dibantu oleh Zep Quiz efektif dalam meningkatkan motivasi berprestasi dan hasil belajar siswa kelas XI. Penelitian lebih lanjut disarankan untuk mengkaji lebih dalam pengaruh penggunaan Zep Quiz terhadap variabel lain, seperti kemampuan berpikir kritis dan kolaborasi belajar.