apart from randomly bumping into walls is there a better way to find them especially in later lvls as maps becomes larger and more complicated so checking all walls takes too much time. Also read on forum that some doors need to be open (yes/no?).Can you post some tips about it as you did in question about golden guirdian?
My ideas about it:
1) you can see the quantity of hidden rooms if open a map
2) (preferable) you can find a map with them dropping from the strongest monster on the floor or the biggest mob.
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