Ellos saben jugar a las cartas.
Conoce las reglas del juego.
I am confused in Lesson 6.8 by these two sentences. I would have used saber for both (since you had to learn the rules to play) but I could maybe see (sort of) conocer for knowing how to play but definitely would have used saber for knowing the rules since that required active study. Instead, these examples are the opposite. Any help?