Siege Engines & Construction Guide

A siege in Mount & Blade II: Bannerlord is not just a battle; it is an engineering puzzle. The engines you build determine whether you will breeze through the walls or die in a hail of arrows at the foot of a ladder.

Planning your siege camp is the first step to victory. Choose your engines wisely.

Siege Engine Tier List

1. Trebuchet

• Role: Wall Breaker.

• Pros: Massive damage. Can destroy enemy walls, creating huge breaches for your cavalry to charge through.

• Cons: Slowest to build.

• Strategy: Build 4 of them to completely level a town's defenses.

2. Onager / Mangonel

• Role: Anti-Personnel / Anti-Engine.

• Pros: Faster to build than trebuchets. Fire versions create splash damage patches that decimate infantry blobs.

• Cons: struggles to break high-tier walls quickly.

3. Ballista

• Role: Sniper.

• Pros: extremely fast to build. accurate.

• Cons: Low damage to walls.

• Best For: Defenders. A fire ballista on defense can snipe the enemy battering ram before it reaches the gate.

4. Battering Ram

• Role: Gate Breaker.

• Essential: Unless you have broken the walls with trebuchets, you must build a ram. Chopping down the gate with axes is a suicide mission in the late game.

5. Siege Towers

• Role: Wall assault.

• Pros: Protects troops from arrows as they climb.

• Cons: Very slow to move. If destroyed, your troops inside die or are stranded.

• Strategy: Only use towers if you cannot break the walls.

The "Reserve" Tactic

The most critical mechanic to master is the Reserve system.

1. Start building a Trebuchet.

2. As soon as it finishes (0% construction remaining), pause the game and click on the engine -> Move to Reserve.

3. Repeat this until you have 4 Trebuchets in reserve.

4. Deploy all 4 at once.

• Why?: If you leave them out one by one, the enemy's defensive catapults will destroy them individually. Deploying 4 at once overwhelms the defenders.

Using the reserve tactic ensures your engines survive long enough to breach the walls.

Defense vs. Offense

• Attacker: Needs Trebuchets. Your goal is to destroy the walls to negate the defender's advantage.

• Defender: Needs Fire Onagers or Ballistae. Your goal is to destroy the Ram and Towers. If the enemy has to use ladders, you win.

Engineering Skill Impacts

Your Engineering skill directly dictates build speed.

• Engineering < 50: Sieges are painfully slow. You will likely starve before the walls break.

• Engineering > 150: You can build a camp and engines faster than the enemy can muster a relief army.

• Tip: Assign a companion with high Engineering as your Clan Engineer in the clan tab.

A well-placed defensive ballista can snipe enemy engines before they even fire a shot.

Summary

• Attack: Build 4 Trebuchets (using reserve trick) -> Break Walls -> Lead Assault.

• Defense: Build Fire Onagers -> Destroy Ram/Towers -> Farm kills at the ladders.

For a broader look at siege phases, see Siege Warfare Fundamentals. To learn how to boost your build speed, check our Engineering Skill Guide.