Siege Warfare & Engineering

In Mount & Blade II: Bannerlord, field battles may decide the fate of armies, but sieges decide the fate of kingdoms. Mastering the art of siegecraft—both the Engineering skill itself and the tactical command of a siege—is essential for any would-be emperor. Whether you are starving out a garrison or holding the walls against overwhelming odds, understanding the mechanics of siege engines and wall integrity is key.

Introduction to Siege Engineering

The Engineering skill is governed by the Intelligence attribute. It determines how quickly you build siege engines, how accurately they fire, and how well you can withstand a siege defensively.

While you can act as your own engineer, it is often wise to assign a companion with high Intelligence and Engineering skill to the Engineer role in your party. This frees you up to focus on Stewardship or Leadership.

Siege Camp & Preparation

When you initiate a siege, you enter the Siege Camp phase. Time pauses, and you must select which engines to build. During this phase, you are vulnerable to outside armies coming to relieve the settlement.

Key Considerations:

• Cohesion: If you are leading an army, watch your cohesion. Long sieges drain cohesion rapidly.

• Food: Ensure you have ample food. If you run out, your troops will wound and desert. Conversely, if the defenders run out of food, their garrison will start to die off, making the assault much easier.

Attacker Siege Engines

Choosing the right tool for the job is critical. You have four slots for ranged engines and one slot for a tower/ram.

1. Ranged Engines

• Ballistae: Great for anti-personnel. They fire fast and can snipe enemy engineers on the walls.

• Onagers: The middle ground. Good damage against walls and troops. Fire versions spread burning oil, dealing massive morale damage.

• Trebuchets: The heavy hitters. These are designed to destroy walls. They have a slow fire rate but massive impact.

2. Assault Engines

• Siege Towers: Allow you to rush a large number of troops onto the walls simultaneously, bypassing the choke point of ladders.

• Battering Ram: Essential for breaking the main gate. Once the outer gate is down, you still have to chop through the inner gate, but the ram gets you through the hardest part.

• Ladders: Always available but highly dangerous. Troops climbing ladders are sitting ducks for archers and stones.

Strategy Tip: The Reserve Trick

When building trebuchets to crack walls, move them to reserve as soon as they are built. Once you have built all four, place them all back on the slots simultaneously. This prevents the defenders from destroying them one by one with their own engines.

Defender Siege Engines

Defending a siege offers a massive tactical advantage. You have unlimited ammo and the high ground.

• Counter-Battery: Prioritize destroying the attacker's ram and siege towers. If you destroy the ram, they must chop the gate down by hand, which takes forever and leaves them exposed.

• Ballistae: Use these to snipe troops bunching up at the base of ladders.

• Fire Onagers: Devastating against tight formations of attackers waiting to climb.

Tactics: The Assault

Wall Breach Assaults

If you have successfully destroyed the walls with trebuchets, you don't need towers or rams. Order your troops to charge through the gaps.

• Formations: Use Shield Wall formation for your infantry as they approach the breach to absorb arrow fire.

• Archers: Place them in Loose formation behind your infantry to suppress enemy archers on the walls.

Tower/Ladder Assaults

If the walls are intact, you must storm them.

• Suppressing Fire: You must win the ranged duel before sending infantry up. If enemy archers are free to shoot, your climbers will be slaughtered.

• The Gate: If the Ram breaks the outer gate, rush inside and help destroy the inner gate. This is often the fastest way to victory.

Tactics: The Defense

Choke Points & Kill Zones

The gatehouse is the ultimate kill zone. Even if the outer gate falls, defenders can rain stones and arrows through "murder holes" in the ceiling while attackers hack at the inner gate.

• Ambush: If you have a strong cavalry force, consider sallying out to destroy their siege engines before the assault begins, though this is risky.

Engineering Skill & Perks

Leveling Engineering takes time. You gain XP by building engines and successfully using them in combat.

Notable Perks:

• Prison Architect: Reduces prisoner escape chance (vital for keeping lords locked up).

• Ballistics: Increases accuracy of siege engines.

• Metallurgy: Increases the health of your siege engines, making them harder for defenders to destroy.

For a deep dive into maximizing this skill, check out our Engineering Skill Guide.

Summary

Siege warfare in Bannerlord is a battle of attrition and geometry. Whether you are cracking the walls of a stubborn town or holding the line against a massive army, the Engineering skill gives you the tools to shift the odds in your favor.

For more on managing your conquests, see our guides on Town Management and Castle Management.