In my talk, I will introduce Blended Interaction, a new conceptual framework that helps to explain when users perceive user interfaces as “natural” or not. Based on recent findings from embodied cognition and cognitive linguistics, it explains how a user’s conceptual system uses ‘blends’ to tie together familiar concepts with the novel powers of digital computation. Blended Interaction helps to draw a line from classical work on UI metaphors, mental models, and direct manipulation to contemporary models in HCI such as image schemas or reality-based interaction. The purpose of Blended Interaction is to give interaction designers and researchers a new approach for generating ideas for future interaction designs and to retrospectively analyse why existing designs worked or not. By this, we hope to facilitate interaction designs that combine the virtues of the familiar physical and social world with that of the digital realm in a considered manner so that desired properties of each are preserved and a seemingly “natural” HCI is achieved. I will illustrate Blended Interaction with several examples taken from my design work at University College London and the University of Konstanz.