The game is played on a board showing the layout of a house with tokens indicating areas that are filled with smoke or actively on fire. There are also a number of "points of interest" that may either be victims in need of rescue or false alarms (you find out when you get there). The goal is to rescue at least seven victims from the building before the building collapses from accumulated structural damage or too many victims are lost.
Each firefighter gets a small pool of actions (move around, extinguish some fire, open a door, etc.) to spend on their turn or save for a later turn; and after every player's turn the fire spreads based on a dice roll. The spread of the fire is very well done mechanically; making the progression unpredictable (the dice could give you anything from gently spreading smoke to a huge cascade of building-damaging explosions) but not totally random (you can see where bad things are going to happen before they do).
What makes the game so tense is the tradeoffs your group must constantly make. Moving victims toward the outside of the house (which you need to do to win) means you're not spending actions fighting the fire (which you need to do to not lose). Chopping a hole in the wall for quick access to a room means adding game-ending structural damage to the house. This means that even the games you win frequently end on the knife edge of disaster; your firefighters pulling the last victim to safety as the house teeters on the brink of collapse.
The game has a two-sided board with different house layouts, as well as a set of advanced rules for older kids and adults that makes the spread of the fire more dangerous (and accelerates the fire over the course of the game); adds explosive hazardous materials and a driveable ambulance and fire truck; and gives each firefighter a specialized role that makes them more or less suited to various tasks (the Rescue Specialist can move and chop walls quickly, but has a harder time fighting fire for example, while Fire Captain can use her actions to move other players' pieces.)
Note to parents of young children and squeamish people – nowhere in the game's rules or imagery is death mentioned specifically. Firefighters caught in the blaze are "knocked down," and start their next turn in the ambulance; while victims are "lost."
[Image: Madeleine Ball. Attribution-ShareAlike 2.0 Generic]