This two-volume set constitutes the refereed proceedings of the 18th International Conference on Interactive Digital Storytelling, ICIDS 2025, held in Saint Julian, Malta, during December 1–5, 2025. The 31 full papers, 4 short papers and 19 Late Breaking Works included in this book were carefully reviewed and selected from 110 submissions. This year, the thematic areas of the conference were organized into five main sections: Theory, History and Foundations; Methods, Tools and Updates; Applications and Case Studies; Social, Cultural and Critical Perspectives; and the Late Breaking works.