Are the monster cards open for everyone to see who is playing?
We have been playing that the stats and abilities are hidden - BUT - we re-read and found this:
3B. Randomize the Chest Markers and
Lay Out Monster Reference Cards
The overlord player separates the chest markers into
their three types and then randomizes each type, making
sure to keep the markers’ number side down. Then, he
selects the set of 12 monster reference cards that corresponds
to the number of players in the game and lays
them out face up near the playing area where all players
can easily see and reference them.
From Vanilla rules.