Keep Defense is an important aspect of PvP in The Elder Scrolls Online. This guide, written by P0nderJaunt, teaches players how to best approach defensive play in contested zones.
Outer Wall Defense
When it comes to proper Keep Defense there are two important aspects of the situation to consider. First and foremost is the direction of the engagement, the second being able to understand how to optimize your response to that engagement. Our first objective as defenders is to confirm direct visual contact with multiple enemy siege. Once the siege has been committed to the battleground we can be safety optimistic that is the location of the assault.
After confirming a assault direction the secondary objective is to initiate a response. The design of the keep comes into play heavily here. If an Imperial Keep is the location of the defense then the inner keep is protected on all sides by a separated curtain wall. For Faction Inner Keeps this design changes as the back side of the Inner Keep intersects the back outer wall with a junction of unbreakable stairs. Imperial (Inner Ring) Keeps are most vulnerable in their rear (The back side of the Inner Keep) as a breach gives assaults access to both the back postern doors with little chance of interception.
Current defensive strategy reinforces this weakness. The correct solution to the problem of these 'backdoors' is called a "Tri-strike Defense". While it is specifically developed to be a counter to the backdoor, it may also be applied with extreme success to lateral assaults as well as frontal ram sieges. The formation calls for specific siege placement based on most efficient angle of attack for each siege type:
- Ballistae: Four should fit up on the top two floors of the perimeter wall towers if the wall outwork upgrade extends on the second floor of the tower. This is the purpose of their small base placement radius. They also drive the assault to the center of the walls due to their high rate of fire which expose them to the catapults...
- Catapults: Catapults have the largest damage radius, and some of the best anti player capabilities. Spaced along the walls the ramparts, they provide such spread that when fired in volley they tag all players in range simultaneously which weakens them for the...
- Trebuchets: Have the longest range and Highest arc for firing. It makes the most sense for them to be placed on the ground directly behind the walls allowing for fired rounds to clear the curtain wall while hiding the exact location of the firing engines from the enemy. The high burst damage they provide on impact aid in wiping healer magicka and health simultaneously.
A generally ignored rule of thumb for firing siege engines in ESO:U is the fact that it's damage is additive. Firing in a volley allows for stacks of maximum damage to be applied and also guarantees hits on all assaulting players in range.
The "Tri-strike Defense" formation is as follows: 5 Meatbag catapults fire in unison along the curtain wall reducing the heals of all gathered in range, at the moment of their release the hidden ground Firepot Trebuchets fire their rounds over the curtain wall. The debuffed healing will now compounded with a high fire damage tick creating proximity heals mayhem for healers. This will cause the groups to stack on all healers for maximum coverage, which is perfect targets for the waiting Ballistae, with now increased range because of the natural height advantage, to stack damage to the limit! All of this siege damage orchestrated on commands of /y"Fire" would create such destruction that truly tactful approaches will have to be made to adjust for this large damage output. Entire siege lines would be crumpled, allowing for sortie and gank groups to burn siege and pursue feeling enemies for clean up.
It may also be noted that the Inner Keeps second floor overhang is great placement for Coldharbour siege because it will not take enemy fire durability damage, and it also unloads the most damage possible to clean up the assaulting force, if they manage to breach, or even as they flee.
This approach should force more front door Battering Ram attempts with stacked siege shields as most normal defensive siege placement will not have the correct angle of attack to counter this (except for tower Ballistae, and the grounded Trebuchets, hence their placement).
If the outer curtain wall or front door is breached, siege needs to be picked up around 10% wall/door HP depending on enemy rate of fire. At this point player groups not on siege should be stacked inside the perimeter wall towers as to hold them from the enemy. This limits enemy placement of siege from countering our inner keep engines. It also makes the enemy choose which tower to rush first, allowing the opposite tower to counter rush from, and flank the enemy while they engage their chosen defenders.
The players who picked up siege in the courtyard should flee into the inner keep where they will replace to provide over watch and supporting fire for the perimeter towers.
If players within the perimeter towers have siege themselves, oil pots covering the stairs up, and a Ballista spaced at the outermost corner of the tower can inflict a lot damage to enemies rushing up. Caltrops should be used on every surface to slow the advance, and stuns should be placed in a way that exposes enemy to oil from above.
Even if the enemy clears the these two towers, the inner keep defenders can sortie out and provide another layer of reinforcement to the chosen tower, or even repair the wall behind the invaders allowing for the defeated defenders to resurrect and ride back.
The "Last Stand" is a situation when the Outer and Inner Keeps are breached. The general attacking strategy is to rush the second floor to clear the powerful archer NPC's as well as the chance of a hold out of defenders pouring oil on their heads. If the assault chooses to rush the second floor, defenders should let them take it; instead drop to the bottom flag nearest the front door, set up two Ballistae opposite each other, one near the scroll basin and the other by the shrine. Defenders should stack just behind the siege engines and place Caltrops and stuns onto the flag, thus allowing for the fight to be fought on top of the guards and allowing for siege, as well as Mage Guards to provide CC and debuffs in aid. The assault will be trapped on the back flag point where reinforcements can assault them from opposite the breach.
Some Keeps have natural geographical advantages, others are hugely at the mercy of their topography. It is up to all well informed players to understand which Keeps are more likely to be attack from. This strategy is weak against an assaulting force with siege at a height advantage, as it exposes the Trebuchets and provides advancing troops with covering fire against our rampart siege.
This is part one of a multi-volume advanced tutorial on Cyrodiil confrontations, concerns criticisms and alternate strategies are welcome from any and all sources!
-@Ponderjaunt Fryst Vinter NADaggerfall Covenant Chillrend