Digital technologies are transforming how cultural heritage is accessed, experienced, and preserved, but many applications remain static, lacking personalization and adaptivity. This paper introduces a modular reference architecture that underpins a serious game-based platform integrating Artificial Intelligence (AI), Augmented Reality (AR), and gamification to support personalized learning journeys in cultural heritage contexts. The system integrates adaptive learning pathways, meaningful gamification, and augmented reality to support user-centric engagement. AI-driven recommendations personalize the path of each visitor through path-based learning activities, adapting to individual behavior, preferences, and cognitive profiles. A conversational AI assistant and spatial AR overlays enhance narrative immersion and support situated learning. The architecture enables curators to create flexible, pedagogically informed content through an intuitive visual design interface. A preliminary prototype demonstrates the technical feasibility of the system and how the integration of AI, gamification, and augmented reality can support the development of inclusive, engaging, and educational cultural experiences for diverse audiences.