Den Defense

Den Defense was a new game mode introduced in Assassin's Creed: Revelations. When Templar Awareness reaches a certain point, an Assassin Den will occasionally be invaded by Byzantine Templars, which would require the Assassin Mentor Ezio Auditore da Firenze to take command of the Den's Assassins to repel the attack.

Gameplay
During a Den Defense, Ezio will command and deploy fellow Assassins to kill approaching Templars. They can only be placed on rooftops unlocked by an Assassin Leader or assigned to a barricade. Several unit types can be deployed, with more types becoming available with each successful Den Defense. Barricades can also be placed to slow Templar progression. Morale is used to deploy Assassins and build barricades, and is gained automatically over time and occasionally from looting Templar corpses. Deployed Assassins can be killed and barricades can be destroyed, forcing Ezio to deploy replacements.

Ezio also has two special actions he can use. He can call in cannon fire, which is limited by a trisected charge gauge similar to the one for calling in Apprentices. A single shot may be used, which deals large amounts of damage to Templar units within its radius. A charged shot may also be used, which calls three cannonballs at once, which deals even more damage and has a larger radius, but consumes all three gauge units. The gauge slowly replenishes over time. Ezio can also fire his Hidden Gun at a Templar, which not only kills the target, but also tells the Assassins to focus on the group the Templar was a part of.

The Templars attack in several waves, with a short period between each wave. They mostly advance up the street, pausing only when encountering a barricade. Dead Templars can be looted for Akce, bomb ingredients or Morale. Should they reach the Den, they will begin damaging it. If the Den's health is depleted, then the Assassins are forced to withdraw, allowing the Templars to use it for their own purposes. Most Den Defenses conclude with the Templars unleashing a powerful War Machine. At the end of a Den Defense, various factors are calculated, which ultimately add up to your total Synch Level for that Den Defense. The Synch Level determines the rewards received afterward, which includes Akce, Apprentice XP and bomb ingredients.

List of Assassin Units

 * Assassin Leader: Does not do anything offense-related, but are vital, as they unlock rooftops, allowing deployment of Assassins on that rooftop. They also increase Morale generated over time. Consumes 10 Morale.
 * Barricade: They are placed in the streets and are used to slow down the Templars. Assassins can be deployed to any barricade type in order to defend it. Typically, one barricade is already placed in front of the Den, which can be repaired if destroyed. Consumes 10 Morale.
 * Greek Fire Barricade: A barricade mounting a flamethrower. It deals large amounts of damage near-constantly, but is only effective at close range. Consumes 20 Morale.
 * Machine Gun Barricade: A barricade mounting a repeating gun. It has an average range and a very high rate of fire, but deals relatively little damage per shot. Consumes 30 Morale.
 * Cannon Barricade: A barricade mounting a small cannon. Long range and highly damaging, but has a very low rate of fire.
 * Crossbowman: An Assassin wielding a Crossbow. Has a high rate of fire, but deals relatively low damage. Consumes 10 Morale.
 * Rifleman: An Assassin wielding a rifle. Deals large amounts of damage, but has a low rate of fire. Consumes 15 Morale.
 * Air Assassin: An Assassin wielding a Hidden Blade. Drops down on enemies from rooftops, instantly killing them, but only if they are close. Cannot attack again quickly, as they must climb back up to the rooftop.
 * Bruiser: An Assassin wielding a medium weapon. Highly adept at melee, but has no ranged capability.
 * Caltrop Bomber: An Assassin wielding Caltrop Bombs. While not dealing much damage, they slow down Templars caught in its effect.
 * Shrapnel Bomber: An Assassin wielding Shrapnel Bombs. They deal damage in a large radius, but cannot be thrown quickly.

List of Templar Units

 * Militia: Weak and poorly armored, their primary danger is in their numbers.
 * Almogavars: Well-armored brutes carrying heavy weapons, they move slowly, making them easy targets.
 * Riflemen: Equipped with a rifle, these Templars can return fire on your rooftop Assassins, but have a low rate of fire and are easily killed.
 * Bombmen: Slow and poorly armored, but are equipped with bombs that make short work of barricades.
 * Scouts: Poorly armored, but are fast and can climb over barricades.
 * Stalkers: Highly dangerous in melee, they attack over the rooftops instead of the streets.
 * War Machines: Heavily armored and slow, these are usually brought in at the very end of an assault.
 * Ram: A heavily armored battering ram, it is limited to melee range, but deals high amounts of damage. It can be noted that the soldiers operating it have the skin of Assassin's Creed 2/Brotherhood militia guards.
 * Greek Fire: A heavily armored platform with a flamethrower mounted on it. It deals large amounts of damage near-constantly, but is limited to close range.
 * Cannon: A heavily armored platform with a cannon mounted on it, it has a very low rate of fire, but deals extraordinary amounts of damage and has a long range.

Source

 * Assassin's Creed: Revelations