Mobile Device based Interaction Patterns in Augmented Toy Environments Matthias Lampe, Steve Hinske, Sandra Brockmann Institute for Pervasive Computing, ETH Zurich, Clausiusstrasse 59, IFW, CH-8092 Zurich, Switzerland {lampe, hinske}@inf.ethz.ch, brockmann@student.ethz.ch Abstract. In our paper, we present the Augmented Knight's Castle, a pervasive playset, which enriches the child's pretend play by using background music, sound effects and verbal commentary of toys that react to the child's play. Radio frequency identification (RFID) technology is used to automatically and unobtrusively identify toys in the playset. Mobile devices equipped with RFID readers are introduced into the playset to provoke further interaction and to enhance the play (e.g., through the integration of interactive learning experiences). We describe two approaches of mobile device integration (mobile phones and mobile devices embedded into toys) with a preliminary analysis of their advantages and disadvantages. One objective of our presented augmented playset is to conduct a user study whose results will help us and others to improve the integration of mobile devices into augmented toys and playsets.