40d:Siege

A siege is a special time in Fortress mode when an army attempts to attack and kill all of your dwarves. It is at this time you should activate your military, raise the draw bridges and pray you've enough food stocks to last the winter.

During a siege, the option on the main menu 'Abandon Fortress' changes to 'Succumb to the Invasion'.

Note: As of v0.27.169.33b, sieges are not functioning properly. The siege groups are content to sit at the edge of the map and wait there until some hapless dwarf wanders too close. After wiping the floor with the dwarf, they return to their spot on the edge of the map.

Siegers

Goblins

Goblins will attack whenever they feel like it, after your fortress reaches a certain point. Possibly triggered by fortress wealth now rather than nobles. Sometimes they will even attack when a caravan arrives.

Come in squads of about 15 goblins each, frequently led by individual goblin weaponmasters (or even evil human mercenaries) and sometimes mounted on beak dogs, and ocassionally accompanied by up to 3 squads of 5-8 trolls. The first siege you see with a given fort might consist of as little as a single unmounted squad with no trolls, but the goblin forces will escalate in size as the game progresses. Later on you may be seeing 100 or more goblins show up in a single siege, all mounted, with 10 to 20 trolls.

Trolls are the goblin "siege engines". They are faster than beak dogs, and will make for buildings and start demolishing. Locked doors will keep the goblins out, but can be demolished by trolls.

If you deflect enough sieges, the ruler of the goblin nation may lead a squad. He's equipped with extra-good quality equipment.

Humans

Unknown if humans still siege this version, someone confirm.

Elves

Unknown if elves still siege this version, someone confirm.

Tips

Active Defense

• Put your entire military on duty. With luck, most of them are not sleeping, eating, or drinking. If a squad leader is is doing anything of that sort, replace him with a more alert squad member (the squad always clusters about the leader. If the leader's eating, the squad will guard the table). Place melee units at major chokepoints, so they can meet the enemy head on, but try to keep them out of direct fire from enemy missile users. Place your own marksdwarves where they can rain death down on the enemies. (This is why you build fortifications.)

• War dogs are valuable, but shouldn't be the first line of defense, because the enemy bowmen will quickly take care of them. Assign them to your military dwarves, or cage them before the siege, and release them via lever/pressure plate as the enemy is rounding a blind corner. They're also useful for clearing the field once the siege ends.

• Siege Weapons, catapults and ballistae, can be effective during a siege, but can also be entirely useless. They don't have a wide field of fire, so you'll need to design your fortress ahead of time to funnel your attackers into the weapons' field of fire and then delay them with winding passages while in range. To use them effectively, you really need trained Siege Operators for the task, since siege weapons take up to three real-time minutes for inexperienced operators to load, and the weapons cannot be fired at a precise time; they will fire whenever the operator shows up. Fire early and often: siege operators are civilians, and will run away once the oncoming hordes get too close.

Passive Defense

• If you have no trust in your military's power, keep all the dwarves inside and pull the siegers into corridors with traps. Stone-fall traps are cheap and easy, but are one-shot traps with a long reload time; weapon traps require weapons, but reload themselves after a few seconds, until they eventually get stuck. A 10-square-long entry hall filled with weapons traps will break most goblin sieges without any help. (How boring!)

• A moat may provide a decent defense when combined with a drawbridge to either keep the goblins from entering, or to drop them right into the water. Substitute magma for some far more lethal results. Even not filled 1-tile wide channel is a fast and effective way to stop siegers or to guide them into areas you want.

Civilians

• Your normal dwarves will still attempt to do their jobs during a siege. The Options->Dwarves Stay Inside option will prevent them from going outside, but only after walking to the entrance. Since many of your major defenses will be inside the fortress, this is only somewhat useful. Dwarves will run from invaders, but only after getting within crossbow-range, so their self-preservation skills are lackluster when the enemy has ranged weapons. Therefore, your best bet is to draft the dwarves in question (or simply all civilians) into one citizen-squad and station them somewhere out of harm's way. However, if any of your citizens are set to carry weapons or armor, they may decide to go collect equipment from slain goblins/dwarves during the siege, which means they'll run out into the fray. Keep an eye on this, and turn off their weapons/armor accordingly.

• Providing indoor pastimes (like sculpture garden, zoo, meeting hall, or a meeting area zone) will make dwarves spend their break time in the fortress rather than outside. This will typically stop all dwarves from hanging around outside. Hunters, woodcutters, haulers and other dwarves who have business outside will still be at risk.

• Lock the front doors. If you still have valuable dwarves outside looking for a way in, you might try the Maxwell's Demon approach: keep locking and unlocking doors just as dwarves arrive so as to keep as many dwarves in as possible. If you don't understand why this is called Maxwell's Demon, read this Wikipedia Article.