In contrast to mobile combat, a siege centers around a fixed location, historically ranging from simple hill forts through to entire fortified cities. For the defenders, their job has been to preserve the integrity of defenses, keep out the attackers, and maintain health, hygiene and nutrition until the siege is broken. The attackers, by contrast, have utilized a mixture of guile, patience, technology and brute force to wear down their opponents, smash through the defenses and force submission.
