Fig 2. Evolution of a Gut Check card—from concept stage to the commercial version.

Throughout the whole process we continuously playtested the game, first for game mechanics, then for card readability, and finally for errors. (A) At the concept stage, “cards” consisted of text in a PowerPoint slide, which were hard to handle when printed. (B) Later, we obtained an open-access card template online that we modified for the prototype version as shown here [28]. This is the step in which the vast majority of playtesting occurred; a script for converting text in an Excel file to the cards greatly facilitated this stage. (C) More playtesting was required for the professional design used in the print-at-home version since we attempted to replace text with icons whenever possible. (D) A final round of testing was required with the new art for the commercial version.