This study focuses on pre-service teachers' experimentation with a game-modding process in a constructionist setting whilst they experimented with randomness embedded in wider socio-scientific issues that call for decision making under uncertainty. In this process, participants created 39 different game mods. Our observations of the participants while they worked on the mods suggest that grappling with wicked problems while using digital socio-scientific games can offer new contexts for harnessing causality to facilitate students' meaning-making for randomness embedded in such contexts. In order to bridge the deterministic and the stochastic in wicked problems, the students transfer agency to specially designed numerical consequences of choices, by inserting proportional thinking, game theory, and probability.