Mount & Blade II: Increasing Battle Size Beyond Limit in engine_config.txt

Bannerlord’s engine utilizes a highly parallelized architecture where every soldier (agent) has its own AI, pathfinding, and physics calculations. The default 1,000-man limit is a “safety net” for mid-range hardware. By accessing the configuration file, we can push the battle_size parameter beyond the slider’s maximum. This guide covers how to safely increase the limit and, crucially, how to adjust the “Sound Provider” and “Animation” settings to ensure the CPU doesn’t choke under the weight of thousands of simultaneous combat calculations.

Hardware Compatibility & Expectations

• CPU Intensity: This is a 100% CPU-bound tweak. A Ryzen 7 7800X3D or Intel i9-14900K is highly recommended for battles exceeding 1,500 agents.
• VRAM & RAM: You will need at least 16GB of system RAM and 8GB of VRAM to handle the increased draw calls and skeletal meshes.
• Stability Warning: Pushing beyond 2,048 agents often hits the engine’s internal memory address limits, which can lead to “Illegal Instruction” crashes regardless of how powerful your PC is.

Backup and Preparation

Before pushing the engine past its intended limits, ensure you have a clean backup.

1. Completely exit Bannerlord and the Launcher.
2. Navigate to the configuration folder (path below).
3. Right-click engine_config.txt, select Copy, and save a backup to your desktop.
4. Open the original with Notepad or Notepad++.

File Location

Bannerlord stores its engine-level configuration in your local Documents folder: C:\Users\%USERNAME%\Documents\Mount and Blade II Bannerlord\Configs\engine_config.txt

Best Config Settings

Open engine_config.txt and look for the following parameters. Update them to these “Epic Scale” values:

battle_size = 2048
number_of_corpses = 500
max_simultaneous_sound_event_count = 512
dof_mode = 0
sharpness = 0.000

Pro Tip: To maintain FPS during the initial clash, set number_of_corpses to a reasonable number (300-500). If this is too high, the engine will struggle to manage the physics hitboxes of the fallen soldiers.

Key Parameters Explained

Parameter	Recommended Value	Impact
battle_size	1000 – 2048	Sets the total number of agents. (Note: Slider in-game will look broken/empty).
number_of_corpses	500	Prevents the physics engine from tracking too many static objects.
max_simultaneous_sound…	512	Essential; prevents audio “popping” or cutting out during 1000+ man clashes.
dof_mode	0	Disables Depth of Field, which can cause severe blurring in massive crowds.

In-Game Settings vs. Config

To support the increased agent count, you must lower some “per-agent” costs in the in-game menu:

• Cloth Simulation: Set to None or Only for Main Character. This saves massive amounts of CPU cycles in large formations.
• Shadow Quality: Set to Medium. Shadows for 2,000 men will crush even an RTX 4090.
• Animation Precision: Set to Low. This reduces the update frequency of distant soldiers’ animations.
• Character Detail: Set to Medium.

Troubleshooting & Common Fixes

• Game Crashes on Battle Start: This usually means your CPU has run out of “Agent” threads. Try lowering battle_size to 1500 and see if it stabilizes.
• Audio Cutting Out: If you hear silence during the peak of battle, increase max_simultaneous_sound_event_count to 1024, but be aware this increases CPU load.
• FPS Drop on Clash: When the two armies meet, the physics engine spikes. Disabling Blood Decals in-game can help alleviate this specific stutter.

Frequently Asked Questions (FAQ)

Conclusion and Expected Results

By manually editing the engine_config.txt, you transform Bannerlord into a true medieval simulator. You can expect massive, cinematic wall-to-wall combat, provided your CPU can handle the load. The battlefield is now truly yours to conquer—at a scale the developers never intended for the average user.