This article details a small project undertaken by Information Skills Advisers at London South Bank University to increase student engagement in lecture theatre settings through the use of a web-based audience response system (ARS), Mentimeter. Supporting the School of Law, librarians delivered an interactive OSCOLA referencing session to a large capacity lecture theatre. A previous session was redesigned to increase student engagement and active learning utilising interactive quiz questions which students answered using mobile devices. The majority of feedback from students and staff who participated in this pilot project was positive and showed an increase in student engagement. This article is based on the presentation, ‘Have You Voted?: Teaching OSCOLA with Mentimeter’ delivered at the BIALL Annual Conference 2017. It will examine the process of adapting a lecture to include interactive content using an ARS, and will discuss the outcomes of the pilot session and explore benefits and challenges inherent in using technology of this type in a large classroom.