idk is an Deck of cards as non-fiction medium by Vaughn Tan designed to support productive discomfort, inspired by his work on The Uncertainty Mindset - Tan.
From its marketing copy:
Each of the 54 idk cards suggests something you can do to be intentionally uncomfortable. This can be something you’re reluctant to do, something you dislike, or something unfamiliar—but it is always designed to help you grow and learn as a result. idk can be used repeatedly and indefinitely.