Impact case studies will form an important part of all universities’ eventual submissions to the next round of the Research Excellence Framework (REF). Drawing on a linguistic and thematic analysis of 175 impact case studies from REF 2014, Bella Reichard, Mark Reed, Jenn Chubb, Ged Hall, Lucy Jowett, Alisha Peart and Andrea Whittle set out the written characteristics that defined high-quality impact case studies in REF 2014 and suggest how they can inform the creation of better impact case studies as part of the upcoming REF.