How Bellwright Simulates a Living Medieval World with Thousands of NPCs

With Bellwright, the team at Donkey Crew is tackling a design challenge many games sidestep: What does it actually mean for a world to feel alive?

Rather than relying on illusion or proximity-based systems, the team built a fully simulated environment where thousands of NPCs carry out routines, gather resources, and interact with the world regardless of the player’s location.

That ambition comes with significant technical tradeoffs, especially when bringing a large-scale simulation from PC to consoles. Memory constraints, system rewrites, and years of iteration have shaped the current version of the game, which blends town-building, survival mechanics, and systemic AI into a single cohesive experience.

We spoke with Sergii Greben, Lead Gameplay Developer, and Florian Hofreither, Lead Designer at Donkey Crew, about how Bellwright evolved, why full simulation was a non-negotiable pillar, and what it takes to make a world feel truly persistent.

For readers unfamiliar with the game, how would you describe Bellwright at a high level?

Donkey Crew: It’s a pretty unique game. You are put into the role of going from a rebel to a ruler, building everything from the ground up.

You experience the rebellion, the town-building, and the command structure all from the ground level. From the very beginning, it was important to us that you are never looking at things from a top-down perspective. Instead, you recruit people, enlist them for your cause, and build everything yourself while experiencing it directly in the world.”

How would you describe the game’s setting? Is it historical or more fantastical?

Donkey Crew: It’s not exactly historical, but it’s also not fantasy. We are going for a medieval setting that feels recognizable to players, but we are not limiting ourselves to a specific century or country.

There’s no magic, no dragons. It’s grounded. We take medieval as a theme and allow players to explore it freely, rather than strictly recreating history.

What engine are you using, and what platforms are you targeting?

Donkey Crew: We are using Unreal Engine 5.

We are preparing for a console release in Q2 this year. We are working through UX and control challenges to make sure the experience translates well to consoles.

What were the biggest challenges when bringing such a complex simulation to consoles?

Donkey Crew: One word: memory.

Older generation consoles, especially Series S, are very constrained. Our game simulates a full world, and fitting that into console memory was a very big challenge.

During development, we didn’t want to limit ourselves too much because we wanted to stay ambitious. We simulate more than a thousand NPCs, and they all act independently, regardless of the player’s position. They have routines, jobs, and behaviors like robbing caravans or traveling across the world.

On PC, it runs fine. On consoles, it was quite painful at first. We had to rewrite a lot of systems to reduce memory usage—almost cutting it in half—to make it work.

We never wanted to compromise on our core idea, which is that the world is real and simulated at all times. Every log being transported, every NPC picking up a resource—it all happens whether the player is there or not.

Many games simulate activity only near the player. Why was it important for you to avoid that?

Donkey Crew: A lot of games create the illusion of a living world, but it’s not actually running unless you are nearby.

You don’t notice it immediately because those games try to hide it, but eventually you realize things behave differently depending on whether you’re there or not.

That was something we wanted to avoid completely. It was very important for us that the world is always simulated, regardless of the player’s presence.

What kinds of technical solutions did you use to make this work on consoles?

Donkey Crew: We didn’t have any ‘low-hanging fruit’ left because the game had already been in Early Access for two years, and we had already done a lot of optimization.

There wasn’t one big solution that suddenly made everything work. Instead, we had to chip away at many small things.

We looked at level streaming, introduced levels of detail for NPCs, and optimized systems piece by piece. At some point, we were celebrating saving 200 MB of memory at a time because that’s how tight the constraints were.

The challenge is also that the console version needs to feel like the full game, not a reduced version. The longer the game is in Early Access, the harder it becomes.

So it really came down to a lot of small improvements across systems rather than one big breakthrough.

Can you talk about how NPC simulation works in Bellwright?

Donkey Crew: All NPCs in the game share the same underlying logic.

Whether it’s a villager, a bandit, a merchant, or someone the player hires, they are all built on the same base system. They just have different roles or enhancements depending on what they do.

So when you meet a bandit, they are not just randomly spawned enemies. They have names, possessions, and behaviors. They exist in the world just like any other character.

It was very important for us to create a world where the player feels like part of a society rather than the center of everything. We wanted to avoid that ‘tunnel vision’ where everything revolves around the player.

How did that philosophy shape the game’s core systems?

Donkey Crew: In early prototypes, we had a more traditional system where NPCs would generate resources automatically. You could assign someone to chop wood, and it would just produce materials over time.

Technically, it worked, but it didn’t feel inspiring. So we changed the approach.

NPCs now do exactly the same things as the player. If they need wood, they craft an axe, find a tree, chop it down, process it, and carry it back.

That was actually very complex to build, but once we got it working, we realized it became a core part of the game’s identity. The player is not unique in that sense; everyone in the world follows the same rules.

Donkey Crew, Game Development Studio

Interview conducted by David Jagneaux

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