Talk based on joint work with Elena Di Lavore, Bart Jacobs, and Pawel Sobocinski. Evidential Decision Theory via Partial Markov Categories (Di Lavore, Roman, 2023) A Simple Formal Language for Probabilistic Decision Problems (Di Lavore, Jacobs, Román, 2024) Partial Markov Categories (Di Lavore, Roman, Sobocinski, 2025)