TJASS, a smart board for augmenting card game playing and learning Mathias Müller University of Fribourg Boulevard of Perolles 21 1700 Fribourg Switzerland mathias.mueller@unifr.ch Tel. +41 26 300 9295 Florian Evequoz University of Fribourg Boulevard of Perolles 21 1700 Fribourg Switzerland florian.evequoz@unifr.ch Tel. +41 26 300 9295 Denis Lalanne University of Fribourg Boulevard of Perolles 21 1700 Fribourg Switzerland denis.lalanne@unifr.ch Tel. +41 26 300 8472 ABSTRACT This paper presents TJass, a smart board that extends regu- lar card playing with computational supports, without modifying players’ habits. The article first presents the functionalities, in particular the learning by trial assistant, and architecture of TJass and further details the hardware implementation and problems encountered. The article concludes with users’ satisfaction comments. ACM Classification: H5.2 [Information interfaces and presentation]: User Interfaces. - Graphical user interfaces. General terms: Experimentation, Human Factors, Algo- rithms Keywords: Tangible Interfaces, Interaction/Collaboration, Augmented Reality, RFID, Card Game INTRODUCTION Recent years have pointed out that tangible user interfaces, a type of human-machine interaction which uses physical objects to interact with digital information, are a promising alternative to classical graphical interfaces. The tangible interfaces have shown in particular an elevate potential to support interaction and collaboration. The goal of this project is to extend card game playing with computational aids in a non intrusive and transparent way to support both beginners and expert players and lead them towards a more elevated and agreeable gaming experience. In comparison to another similar system mentioned in [1], which uses TFT display, the output devices in Tjass have been designed for a maximum transparency and a mini- mum intrusiveness. Furthermore, while help is provided by a relative unpractical PDA in the Smart Playing Cards project [1], Tjass beginner’s assistance is directly available on the game board. In the traditional jass card game the players have to count and notate manually the scores. As well they need to ob- serve continuously the status of the score to determine the winner team. In addition the rules of jass are complex and require keeping in mind the overview of all played and remaining cards. Therefore beginners often have difficul- ties to learn the game. Tjass will disburden the players of these tasks by (1) counting and displaying the score auto- matically in real time and (2) putting at beginner’s disposal a decision assistance to teach them the game. TJASS FUNCTIONALITIES AND ARCHITECTURE TJass avoids the use of mouse, keyboard and monitor, in order to preserve card players’ habits and guarantee non- intrusiveness. Instead an augmented game board and real cards are preferred. Tjass design has been guided by this motto, augmenting gaming experience without modifying players’ traditions. Each card is marked by an RFID tag that identifies it uniquely (Fig. 1d). An RFID reader is then used for card identification and game observation. Physical devices built using Phidgets [2] are used for additional interaction during the game. Fig. 1a illustrates the setup of Tjass. On each side of the table resides a player. Each of the 4 players is supported by one antenna which is attached under the table right in front of him (Fig. 1c). The card detection zones for the players are marked in Fig. 1a as rectangles in front of them. The playing zone is the square in the middle of the table. To get into that zone each card passes through the sensor field of an antenna. This feature guarantees habitual playing comportment like in the traditional jass. To help the players know who shall play, the yellow led in front of the active player will blink. If a played card is valid according to the rules of jass, the green led lights up and a discrete sound is played. If the card is not valid, the red light will blink and the player should play another card. This prevents mistakes and denounces cheating attempts. Other sonorous outputs acknowledge for several events like announces, end of game or trump selection. Another RFID reader, a single tag short distance reader, allows users to define the trump color in a tangible way by putting trump tokens on the antenna. When a round is finished, the points are calculated and added to the score. The round points and the global score are then shown on each player’s LCD (Figure 1a). In addi- tion, to provide a constant score overview, the score needle © Copyright Mathias Müller, Denis Lalanne, Florian Evequoz. University of Fribourg, Switzerland. 2006.