In this chapter, we address one of the most frequently mentioned concerns of new teachers, namely what to do when things ‘go wrong’ or the session goes ‘off script’. We start by exploring the concept of improvisation and how this relates to teaching. We then move on to discuss Keith Johnstone's concept of status, which is particularly important in stand-up comedy performance. We then return to Stanislavski's work, this time drawing on his technique – the ‘Magic If’ – and explore how this might be used to help prepare teachers for hypothetical, but realistic, unprepared circumstances. This is followed by an introduction to American actor and teacher, Sanford Meisner's repetition exercise, which aims to get actors – or teachers – out of their heads and promote spontaneous reactions to circumstances as they unfold. Finally, we present some of the improvisation games devised by theatre academic and acting coach, Viola Spolin, and explore how these might be used with students in the classroom.