One thing I wanted to do was keep an air of mystery about certain things in the game. With the entire section of the map laid out at once, with the stats for the enemies and obstacles written on the map for all of the players to see, how can I keep back some information for surprises?
I have solved this by creating a “Book of Secrets”. This is an A6 size book that will have one piece of information on each page. During various parts of missions, the players can do things which means they can look up a secret in the book.
A good example is the map I am working on at the moment. This has a flask with next to it. In the Notes section of the map, it states “Section S: As a free action on their Action turn, a player can attempt the Intelligence check if they are able to target section S. If they succeed, consult page 45 of the Secrets book.”
Could it be a healing potion? A Molotov cocktail? Who knows. But once the player makes a successful Intelligence check, they can look up what the flask does and may be use it to their advantage, or try and avoid it at all costs.