In the first prototype, the game included equations and practice mathematical calculations. The issue was that these calculations were not directly connected to the overall goal of the game, accomplishing the Rube Goldberg challenge. As the calculations were not enjoyable for participants and did not support the goal, players suggested the calculation component be removed.
I removed the mathematical calculations, and instead bolstered the content knowledge background supplied on the energy transfer card and required that players verbalize the energy transfer they were creating.
I also chose not to include thermal and chemical energy transfers to ensure this game could be safely played indoors.
The result was that players with any level of background in math and physics could learn about energy transfer and participate fully in the game.
Taking out the mathematical calculation component also allowed the game to progress more swiftly. However, with this, more cards were being used throughout the game. It became clear that players were running out of cards to use in play and I had not developed instructions for this scenario.
To fix this challenge, I produced additional copies of cards and also created explicit game instructions for recycling cards in play. In the case that players use all cards, they are to shuffle the discard pile and add them to the deck in use.
This adjustment clarified how players should react in the case they run out of new cards, and the solution is familiar, as many games use the same recycling process.