According to Dillenbourg et al (1996) collaborative learning occurs when two or more people try to learn something together. This process consists of four successive stages, one of which concerns collaborative interactions. In this paper we present two studies that implemented two different ways of increasing the number of collaborative interactions. To increase the number of collaborative interactions in a game, the first study focused on degrees of collaboration (Kahn and Mentzer, 1996) and the second study focused on cooperative gestures , which were used in the third degree of the first study. In order to facilitate collaborative interactions and its properties (Dillenbourg, 1991), we decided to design two digital tabletop games with tangible interaction that both require collaboration to win. The evaluations in both studies, by means of the Wizard of Oz method, showed a significant increase in collaborative interactions. We also found that verbal and gestural interactions are a better measure criterion for tabletop games than how much people look at eachother.