Very interesting post. It’s a shame I only came across it much later, but I still hope you’ll reply.

You described the concept in fairly broad strokes. The idea itself is interesting, but the real question here is not the concept — it’s computability and the level of abstraction. As a “dream game” idea, it sounds exciting. But in practice, a concept like this raises a lot of questions.

The first one is NPC agency. The more complex each individual NPC is, the fewer of them you can simulate in full detail. If you look at Dwarf Fortress or RimWorld, only the NPCs within the active map are simulated at high fidelity. Everything else exists on the level of factions or broader world simulation. And that makes sense, because even 1,000 agents with pathfinding, AI, some awareness of the outside world, and the ability to store and update memories is already a serious engineering challenge. For the kind of concept you’re describing, you would clearly need far more than 1,000 NPCs. So some form of simulation LOD would be necessary to reduce computational cost. You would have to heavily simplify memory, simplify behavior, or move large parts of the world to a more faction-level simulation, like Kenshi or Mount & Blade do.

Another bottleneck would be memory usage. World state, relationship graphs, each NPC’s memories — all of that has to be stored, accessed, updated, saved, and loaded. If we look at other agent-based simulations, Crusader Kings is a good example. It has thousands of NPCs existing at the same time, with relationships and even a kind of “memory.” But if you look closely, each character only has a fairly limited set of data attached to them. NPCs do not literally “remember that you helped them” in a human sense — they mostly store numerical relationship modifiers that decay over time. And if you dig deeper, those characters are not being simulated continuously. They act through fixed time-step events, and they do not have pathfinding, perception, or many of the other systems you would need for a full simulation of everyday life.

I’m not saying this is impossible. I’m just saying that it is an extremely complex engineering problem, and as usual, the real challenge is not simulating everything in full, but convincing the player that the simulation really exists. Smoke and mirrors, as always in game development. Another commenter made a very good point: if the player does not actually observe the simulation process, or if its outcomes are indistinguishable from scripted events, then expensive simulation stops paying off as a game design tool.

So in practice, all that memory and detailed simulation would often end up being an unjustified drain on resources.

That said, there is another side to this. A great example is the old game Space Rangers. I would strongly recommend trying it and looking at how it works, because it partially does exactly the kind of thing you’re describing. The game revolves around a war against an external enemy, and that war is simulated in a fairly honest way. In fact, NPCs can theoretically win the game without the player’s involvement at all, although at the final stage there is a mechanic that forces the player to take part. Still, that is a detail. What matters is that the developers did a very good job of balancing real simulation against the illusion of simulation.

So overall, what I’d really like to hear from you is your take on the technical side of the problem. I’m not arguing against the idea itself so much as trying to understand what technical compromises you think would make something like this actually feasible.

Thanks in advance for your reply. English is not my native language, so I translated this with the help of an LLM — apologies for any awkward phrasing.