Fort defenders can survive if they retreat during a sally (break siege). They can retreat to any neighboring friendly provinces. They just can't retreat back into the fort.
Apparently nearly all forts have a secret escape passage in the rear. "To the tunnels!"
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Whether he submitted the post, or whether he did not, made no difference. The Thought Police would get him just the same. He had committed— would still have committed, even if he had never set pen to paper— the essential crime that contained all others in itself. Thoughtcrime, they called it. Thoughtcrime was not a thing that could be concealed forever. http://z7.invisionfree.com/Dom3mods/index.php?