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".
A tension room is a dungeon room that is filled with monsters, usually related to each other by a particular theme. An example is a room containing a werewolf and multiple wolves and dire wolves, or a room containing a gnoll chieftain and multiple gnolls and large gnolls. 'Mixed' tension rooms—containing various monsters including those of higher danger levels—may also be found.
The door to a tension room is often locked and trapped. Once opened, the walls surrounding the door will collapse (leaving behind piles of rocks) and a message is generated depending on the type of monsters in the room. These properties generally distinguish tension rooms from threat rooms. Note that tension rooms generated in the Village Dungeon don't seem to abide by these general rules, usually being filled with two different species of monster that are often unrelated to each other and not generating any sort of special message (except for the one about the walls being destroyed).
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.
Tension rooms are easy to locate on a level by means of monster detection. PCs that are blinded by a trap whilst breaking into a tension room can still try to identify what monsters they are facing from the message generated, as this tends to usually relate to a sound or feeling rather than a sight. Some examples:
- A mulitude of angry sounds: mixed tension room
- Many squeaking sounds: rats
- Yelping war cries: kobolds
- Hoots and wails: hobgoblins and goblins
- Orcish battle cries: orcs
- High-pitched grunts: gnolls
- Many howling sounds: wolves
- An enormous stench of decay: lesser undead
- A flood of chilling terror: ghosts
- This shop seems to be deserted: mimics