Uh oh

A siege is when your town is attacked by things like goblins, slimes, spiders, goblins or other monsters. if you are lucky, you can establish a good defense and a solid food production before you are attacked.

As of .45, Sieges pause the game when they occur. It is suggested that you convert all your Civilians into Soldiers for the duration of the Siege so that they will all band together in the fight instead of allowing themselves to be picked off one by one.