Tension rooms are one of the most commonly occurring dungeon features in ADOM. The player can detect a tension room on the dungeon level by the occasional occurrence of the message "You sense a certain tension". The type of monsters found in a tension room seem to relate directly to the current danger level. Whilst weak monsters like rats and kobolds are found on dungeon levels early in the game, PCs in the mid-game should be very careful to avoid tension rooms in the Dwarven Halls.