This is a moment when children desperately need to be taught how to responsibly interact with these technologies, especially artificial intelligence (AI) and large language models. Learning about responsible AI and Large Language Model (LLM) use has not been achieved so far through traditional methods that do not profoundly engage adolescents as active learners. This paper discusses the gamification method as a new approach in teaching responsible AI/LLM use among adolescents aged 13–17 years. We employed a mixed-methods strategy that combined both a randomized controlled trial involving 500 students across 10 schools and also qualitative interviews along with behavioral observations. Students were divided into two groups: The first group received traditional lecture-based instruction, and the other was engaged with a custom-designed educational game including AI ethics scenarios. The results showed higher knowledge retention on the topic and better decision-making abilities with respect to ethical dilemmas surrounding AI in those with the gamified strategy against the control group, with p-values of less than 0.001 and 0.01, respectively. Students in the gamified group also reported higher motivation toward acquiring more knowledge about AI ethics compared with the others, and more long-term engagement with the material. These findings suggest that gamification may become a powerful tool in the cultivation of responsible AI literacy among the youth-ridding or mitigating some future ethical challenges as this generation engages deeper with AI technologies. The study concludes by proposing a framework for integrating gamified AI ethics education into school curricula.