Terror level
The terror level (as marked on the terror track) represents the current mental state of Arkham city's inhabitants. Certain game events, such as too many monsters entering the Outskirts or certain Mythos cards, can cause the terror level to increase - causing store locations to close and allies to leave town. If the terror level becomes too high, Arkham city becomes completely overrun with monsters.
Terror mechanics
At the beginning of the game the terror level on the Terror Track is set to 0. Each time the terror level rises the terror level marker is advanced along the terror track and one Ally card is removed from the Ally deck and returned to the box. Allies removed this way are no longer available for the rest of the game. If all Allies have been removed from the Ally deck this specific result has no effect.
Increasing terror
When the number of monsters in the Outskirts exceeds the monster limit, all monsters in the Outskirts are returned to the monster cup and the terror level is increased by 1.
If playing with the Dunwich Horror or Innsmouth Horror expansions, the terror level increases whenever a monster enters a vortex space.
If the Ancient One is Glaaki, the terror level will raise by 2 if an investigator is devoured.
If playing the King in Yellow expansion, The Next Act Begins! mythos card will increase the terror by 1.
Closing locations
As the terror level increases, certain locations begin to close down: a closed marker is placed over that location and neither investigators nor monsters can enter.
- If the terror level reaches 3, the General Store is closed. Any investigators or monsters on this location are moved to the Rivertown street area.
- If the terror level reaches 6, the Curiositie Shoppe is closed. Any investigators or monsters on this location are moved to the Northside street area.
- If the terror level reaches 9, Ye Olde Magick Shoppe is closed. Any investigators or monsters on this location are moved to the Uptown street area.
If the terror level reaches 10, Arkham is overrun and the monster limit is removed for the rest of the game. Return all monsters in the Outskirts to the cup.
Once the terror level reaches 10, if it ever increases again a doom token is added to the Ancient One's doom track for each point the terror level would have increased.
Preventing increases
There is no way to lower the terror level once it is raised, except during Final Battle during a plot with Glaaki. However, it is possible to prevent the terror level from going up.
- Charlie Kane has a special ability to prevent the terror level from increasing by spending two clue tokens. His Personal Story can increase or decrease the number of tokens require.
- If Tommy Muldoon passes his personal story, the next time the terror level is increased, it is prevented.
- Discarding the Director's Diary Tome will reduce a terror level increase by 1, preventing an increase if it will only raise by 1.