We introduce rapid game jams, a style of game jam that takes only 1–2 h and is focused on design experimentation rather than on programming and technical implementation. To support that kind of rapid game-design experimentation, we have designed a class of games that we call fluidic games. These are mobile games in which the game mechanics and other aspects of the games are editable on the fly, directly on the device, allowing for frequent play/design context shifts. We have conducted four rapid game jams with 105 participants from a local Girlguiding organisation, in order to gain real-world experience with this concept. We analyse results from a survey instrument completed by 69 participants in two of these rapid game jams. In order to guide future work in addressing questions left open by this study, we did a qualitative analysis of the designed games to gain additional insights into participants’ design practice.