In addition to the above: when you roll higher than the monster rating but there are already 4 monsters on the map tile your character is standing on, do not add a new monster but increase the monster threat track by 1 instead. If someone else is standing on a different map tile which has fewer than 4 monsters, he/she will still have to add a monster on a higher roll.
Also, of course, if all monster spawns on your map tile are explored (sealed), you won't have to roll at all.
Yes indeed, an explored monster spawn (explored token on top of it) is of course sealed. I'm probably a bit too used to the way the rulebook describes things. Which is a bit confusing and hopefully the new rulebook will be a bit more understandable in its terminology. I'll add sealed to my post to make it a bit more clear.
Thanks for that! I recently bought the exclusive edition off ebay and found the rulebook (although super pretty) to be very disjointed.
The three page summaries here on BGG are very useful. Also this was my first post here on BGG, hope to be an active member of the community as I just got into designer board games (eldritch horror being my first)