M. Rauterberg (Ed.): ICEC 2004, LNCS 3166, pp. 339–344, 2004. © IFIP International Federation for Information Processing 2004 The Design and Implementation of Multi-player Card Games on Multi-user Interactive Tabletop Surfaces Shwetak N. Patel, John A. Bunch, Kyle D. Forkner, Logan W. Johnson, Tiffany M. Johnson, Michael N. Rosack, and Gregory D. Abowd College of Computing & GVU Center, Georgia Institute of Technology, 801 Atlantic Drive, Atlanta, GA 30332-0280, USA {shwetak, bunch, dasbrute, logan, tif, michael.rosack, abowd}@cc.gatech.edu Abstract. We present the design and implementation of a card game architecture for mulit-user interactive tabletop surfaces. Our system is built on the DiamondTouch, a touch-sensitive input surface that allows several users to interact with a program at the same time. We describe the software architecture and present Blackjack as a sample implementation using this framework. 1 Introduction and Motivation Card games have been around for generations. From classic games like Poker and Blackjack to relatively recent ones like Magic the Gathering, card games have entertained and educated us in countless ways. Almost every card game has been digitized in some form or another; Blackjack is a good example of this. Most interactive systems for card games today are limited to the desktop where interaction is usually achieved indirectly through a mouse or keyboard. Systems that allow a more direct interaction have also been available for some time now like touch screen monitor overlays or touch screen laptops and PDAs. In addition, the latest Tablet PCs allow direct pen-based interaction. Smart technology also offers an interactive whiteboard called Smart Board [5], which employs a touch system similar to the Tablet PCs. However, these systems only allow for single user interaction. These systems could be extended so that they detect multiple inputs, but they would still lack the ability to differentiate between users and resolve multiple interaction points for a particular person. With these systems multi-user applications are limited to only sequential user interactions, making is unsuitable for many multi-player card games. We describe our exploration of the DiamondTouch as a viable card game platform. The DiamondTouch is a touch-sensitive input surface that allows several users to interact with a program at the same time. Although current research has focused on collaborative workspace applications [1, 0, 4], we particularly focus on card gaming and show how we can create a rich gaming experience despite the loss of some physical affordances. We also present a software architecture written in Java that allows users to quickly implement a wide variety of card games on the DimondTouch, and we show Blackjack as an example.