There are three types of environmental hazards: fire, flood, and blocked hatches.
Fire is caused by certain events. It has the following effects:
A gnome cannot enter a room that is on fire unless he uses a Grog or Fire Extinguisher during his turn.
The only action a gnome can take in a room on fire is Extinguish Fire. If a gnome fails to extinguish the fire, he must immediately leave the room (at normal time cost) if possible.
Any fainted gnome in a room on fire is killed. If the active gnome begins his Updates Phase in a room on fire, he is killed.
A flooded room can never be on fire. If a room on fire becomes flooded (at any level), the fire goes out.
When an event causes a Fire token to appear, the Asphyxiation Track Marker advances one space.
Rooms can become flooded due to events or during the Reflow Water Step of a gnome's movement. There are two levels of flooding: low water and high water. Flooding has the following effects:
A gnome may never enter a room with a high-water Flood token. Moving into a room with a low-water Flood token costs one minute.
When a hatch is opened between a room with a high-water Flood token and a room with a low-water Flood token or no Flood token at all, the water level in both rooms becomes low water.
The only action that can be taken in a room at high water is No Action.
Any action except No Action or Pump Water taken in a room at low water costs an additional two minutes. These two minutes must be paid first, before calculating the gnome's chance of successfully completing the action.
Any fainted gnome in a room at high water is killed. Fainted gnomes are safe in low water.
If the active gnome begins his Updates Phase in a room at high water, he is killed.
A flooded room can never be on fire. If a room on fire becomes flooded (at any level), the fire is extinguished.
Hatches are the only connection between rooms on the Red November.
They can become blocked by events.
Only interior hatches can become blocked. Exterior hatches are never blocked.
Blocked hatches cannot be opened and gnomes cannot pass through them.
Blocked hatches do not prevent fires from spreading and have no effect on flooding.