Sally&Molly: A Children’s Book with Real-Time Multiplayer Mobile Augmented Reality Gabriel De Ioannes Becker gdeioannes@gmail.com Bauhaus-Universität Weimar Weimar, Germany Eva Hornecker eva.hornecker@uni-weimar.de Bauhaus-Universität Weimar Weimar, Germany ABSTRACT The book ’Sally&Molly’ is for children aged fve to ten, a phase where children transition from a self-centered view of the world to social understanding. Via mobile AR we ofer a second layer to the book and playful activities with it. We describe the design and design rationale, and explore cooperative real-time multiplayer mechanics for children in mobile AR. CCS CONCEPTS · Human-centered computing → Mixed / augmented real- ity; Collaborative and social computing theory, concepts and paradigms; Ubiquitous and mobile computing design and evaluation methods; KEYWORDS AR Gaming, Game Design, Augmented Book, Reading, Play ACM Reference Format: Gabriel De Ioannes Becker and Eva Hornecker. 2021. Sally&Molly: A Chil- dren’s Book with Real-Time Multiplayer Mobile Augmented Reality . In Extended Abstracts of the 2021 Annual Symposium on Computer-Human In- teraction in Play (CHI PLAY ’21), October 18ś21, 2021, Virtual Event, Austria. ACM, New York, NY, USA, 7 pages. https://doi.org/10.1145/3450337.3483498 1 INTRODUCTION The project Sally&Molly focuses on game design for children in a real-time, multiplayer, mobile handheld AR video game. This was developed in two stages. The frst relates to characters and narrative creation; it focused on the creative development of the traditional, physical book and its story, including play mechanics. The second stage enhances this with a technology layer. Developing the book in stages enables us to distribute and test a version that in itself is complete and has permanent value for its users. As the physical book is available for purchase, this also simplifes user testing with a global user base, as participants of studies only need to download the game app. There are several reasons for choosing a see-through augmented reality (AR) approach with a physical book as a base instead of purely virtual game play. The project’s main aim is mobile game- play that is appropriate and healthy for children’s transition from Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for proft or commercial advantage and that copies bear this notice and the full citation on the frst page. Copyrights for third-party components of this work must be honored. For all other uses, contact the owner/author(s). CHI PLAY ’21, October 18ś21, 2021, Virtual Event, Austria © 2021 Copyright held by the owner/author(s). ACM ISBN 978-1-4503-8356-1/21/10. https://doi.org/10.1145/3450337.3483498 the pre-operational to concrete operational period [16]. We take into consideration diferent views regarding children’s development concerning technology [12, 14] and video game experience design. The video games for health movement [4] proposes to design for positive, healthy benefts. However, it has been debated that this view lacks emphasis on the spectrum of human emotion that video games can elicit [7, 18]. Playground design research [5] identifed a fruitful overlap between these perspectives, and argues for a holistic view on the range of decision making in play activities: for their development, children need physical, emotional and intellectual stimuli in the full range possible. With our approach, a physical book can encourage bodily experiences which are benefcial for playing [21, 24], gives ownership to children, and can easily be socially shared, ftting into common parent-child reading patterns and roles. Moreover, with Sally&Molly, social gaming can transition from a single play ’local’ activity to shared play and remote multiplayer game play. In this work in progress, we develop and preliminary tested a demo application that showcases the possibilities of an AR for single-play and cooperative multiplayer play mechanics in diferent play scenarios using the book. 2 AR FOR CHILDREN The idea for AR books has been around for a considerable time [6, 10, 22]. Advances in ubiquitous mobile technologies have now made AR accessible for large audiences. The research classifcation made in 2016 by Altınpulluk and Kesim [3] needs an update since there has been a considerable amount of new investigation in the fve years since. However, there is still not much work on AR Books with real-time multiplayer experiences. Instead, among other topics, environment mapping is investigated for multiplayer experiences, as with EmoFindAR[19]. With the new technologies, one could think that AR Books are a thing of the past. However, people still enjoy physical books, sometimes because of their print quality, physicality (material qual- ities), and being able to own them [13, 20, 23]. Studies on AR and children’s development [9] mention social and physical benefts. For instance, Pokemon-Go allows children to participate in group activities and provides shared topics for interacting in groups [9]. Studies have found that children quickly understand AR overlays on books, that they need clear feedback on progress or ’success signals’, and that age-appropriate choice of story and interaction are important [10]. As AR books are still novel for consumers and younger children, there is still much to be explored and researched. The technologies allow new forms of social play with a physical object in real-time, introducing novel and healthy ways of social- ization in video games for younger children. 80