Digital multimodal composing (DMC) is the production of texts using multimodal semiotic resources and digital tools. This study integrated critical literacy pedagogy into DMC in an EFL context through both course design and task design, proposing digital fairy-tale rewriting (DFTR) as a genre of DMC for critical literacy practices. Taiwanese university students in the study created multimodal videos of retold fairy tales addressing social issues to promote critical literacy. The study adopted a conceptual framework of DMC affordances to examine the possibilities afforded by DFTR. Affordances refer to the potential and limitations of a mode for meaning representation and communication, as perceived by teachers and students. Data collected included participants’ surveys, reflective writings, and analysis of the DMC artifacts. Results indicated substantial evidence of technological, educational, and social benefits of DFTR compared to past learning experiences, with enhanced affordances including transmediation, multiliteracies, creativity, and civic participation. Digital skills and multimodal literacy were developed to strengthen critical literacy learning across four dimensions, enriching prior studies on DMC affordances and critical literacy scholarship. The study also contributed a refined conceptual framework of DFTR affordances, expanded by new affordances of generating interest, nurturing creativity and multiple perspectives, and promoting more active civic participation.