1. CastlesA Strategy Game Exploring Mobile Collaborative Adaptive Software • Matthew Chalmers, Malcolm Hall, Marek Bell • University of Glasgow, UK

2. CastlesAnd Some Other Seamful Games • Matthew Chalmers, Malcolm Hall, Marek Bell • University of Glasgow, UK

3. Background • Seamful games as a testbed for ubicomp research • ‘Seamfully’ revealing system structure and use • Combining histories from multiple people, programs & devices • Using wireless networks to share or disseminate information • Bandwidth and memory: constraints and possibilities • Wired and long-range ‘infrastructure’ wireless networks: slow/costly? • Short-range wireless networks, e.g. 802.11, UWB: fast and free? • Substantial memory in mobile devices (backed up by servers online?)

4. Treasure (a.k.a. Bill) • Two teams of players, Blue and Green • Each player has PDA+802.11+GPS • Designed for disconnection • Server drops coins on each PDA’s map • Coin locations often outside network • Only receive this info when in network • Get close, pickup coins, get back into network, upload, get points • Pickpocket: steals another player’s coins • Only works when in network area • Shield: protection from pickpockets • Real-time maps of sampled coverage • Based on history of movement

5. Bandwidth and Memory • 802.11: hot spots set in cold expanses • Cost and ownership are significant constraints too • Many 802.11 apps assume constant access to one network • …but perform poorly on mobile devices that are really mobile • Peer-to-peer mobile ad hoc networks • Rely less on central servers, active Internet connection, particular access points, having a specific static IP address… • Issues of transience and security • High short-range bandwidth, taking advantage of local storage • New possibilities for interaction and gaming

6. Monopoly • Wi-fi hotspots in the city are used as ‘properties’ • Players’ PDAs detect and identify wi-fi access points • First player to find a property can ‘buy’ it • Other players owe rent if they pass by • Rent paid in face-to-face meetings between players • Information spreads peer-to-peer, between players • Small ‘ad hoc’ networks between players’ PDAs • Epidemic algorithms for spreading state P2P • Rent due, players’ locations, new properties, bids to buy, offers to sell…

7. Yoshii Feeding (Illegal Version) • Some play is indoors/online • Home wi-fi used like a (glowing) hotspot for street players • Also maps, stats and similar web paraphernalia • Most play is out in the street with PDAs • Looking for wi-fi hotspots and other players • Can auto-connect to net through AP? • A Yoshi lives there (and a Yoshi likes fruit) • Bring Yoshi its desired fruit to get a game point • Can’t connect through the AP? • It’s presented as a plantation, to seed and pick fruit from • Players can connect to each other directly: MANETs • Swapping/stealing fruit, and info on plantations & Yoshis

8. Yoshii Feeding (Legal Version) • Some play is indoors/online • Web site shows game score tables • Most play is out in the street with PDAs • Looking for wi-fi hotspots and other players • Open AP? • A Yoshi lives there (and a Yoshi likes fruit) • Bring Yoshi its desired fruit to get a game point • Closed AP? • It’s presented as a plantation, to seed and pick fruit from • Players can connect to each other directly: MANETs • Swapping/stealing fruit, and info on plantations & Yoshis • Stripped-down version available atwww.yoshigame.com

9. Castles: First Prototype

10. Domino • Castles’ subsystem for handling assemblies of software components • P2P ad hoc recommendations of software modules • Dynamic sharing, dependency resolution and integration • Recommendation based on patterns of use, and on classes and dependencies • But users express utility or contextual relevance in and through their use • Designers specify module’s class and class dependencies • Social and technical means for security and privacy • Transfer done as part of face-to-face game play • Also: certification of modules? Sandbox? Showing logs of use?

11. The Current State of Affairs • Legal Yoshi user trial just finished • Stripped-down downloadable version just made available • Pilot runs of Castles recently done • Same base set of 54 components: buildings, adapters and units • And also two other buildings, two other adapters, one extra unit • Recommendations helped players who had poor setups • Full trials of Castles beginning in October • Interface and comms improvements, larger component set • Video and system logs sync’d for playback in Replayer tool • Issues of uniformity of system structure: the cost of winning battles? • Building Bluetooth version of Domino infrastructure • Links with U. Nottingham, UCL, U. Bristol and Blast Theory

12. Conclusion • Games as a testbed for ubicomp, ubicomp as a testbed for games • Exploiting fast comms and storage of mobile devices • Seamful exposure of system (infra)structure • Past use as a resource for adaptation of system structure and ongoing use • Castles: system adaptation as part of a multiplayer game • More coarse-grained and accessible than modding code • How will players handle dynamics, develop strategies and adapt game play?

13. matthew@dcs.gla.ac.uk www.dcs.gla.ac.uk/~matthew www.equator.ac.uk