Suddenly, the fire alarm goes off. Everyone is rushing for a door, but the exit sign glows at the other side of the room. Do you head toward it on your own or follow the crowd? More than 500 people were faced with this and other scenarios in an online simulation. The game was created to study people’s decision-making in an evacuation. Most of the insights into how people behave during an evacuation have come from interviews with survivors of real evacuations or from computer simulations, and even a few experiments with people (pictured above). By including players, the new game makes the computer modeling more realistic. One surprising result: People tend to follow the herd, even when others seem to be heading the wrong way . (Sometimes “wisdom of the crowds” is a misnomer.) The hope is that the game, described today in the Journal of the Royal Society Interface, will reveal safer ways to design buildings and evacuation procedures. Want to make it out alive? Play the game yourself .