Tarn Adams and his brother design Dwarf Fortress following this principle.

They have these things called “Power Goals” which are like miniature stories or scenarios that should be able to occur naturally in the game. Tarn then goes on to implement the gameplay elements that should allow such a scenario to *emerge* naturally.

The big hidden benefit to this is that you also get many *other* possible scenarios that you didn’t even think of. For example, when Tarn added sewers to the game, he went exploring them and discovered that killer Hippos had appropriated the sewers as their home. This wasn’t something he programmed in specifically or had even considered, it simply emerged naturally as a consequence of how creatures are placed in the world.

My favorite example is something that might even sound like a bug:

I once discovered a magma pit while digging a fortress. Certain fire creatures lived in this pit and would harass any dwarf that got near the pit. So I sent my most badass dwarf to the pit to kill an Imp that was particularly dangerous. Once he killed it, since he was a hunter, he carried the corpse to the butchershop. There, the butcher chopped it up and brought the Imp’s meat to the nearby food barrels. Shortly thereafter, my entire food supply had caught on fire. Fire Imp flesh is made of *FIRE* — and so once it sat in a wood barrel long enough, the barrel burst into flame, and the fire spread — destroying my entire food supply!

So needless to say, emergent game design makes for a much more immersive and genuine story since it is literally something that “just happens” in the game world. Think about it: the most interesting stories you hear people tell about games are how the mechanics of the game lead to novel events, not about some cut scene after a boss fight.

Its also very true when it comes to what you say about the problem Soldat has. KAG faces this very same threat as well.
Currently people buy a discounted game with promise for the rest of the game being free. This works, for now, but its not going to last.

It simply can’t last and eventually there will be a moment where MM is working on the game that everyone has already bought and all the extra work he does is pretty much done for free, he’ll quickly find himself asking “why am I doing this again? I’m not getting paid!”. Now, you could argue that you can work on the game out of love as a hobby, but this happens to be his primary job and you need to earn that money somewhere to survive anyway, he’ll either have to:

a) add commercial advertising to the game
b) break a previous promise and make future content be paid
c) abandon KAG and make a new product

I sound pretty grim here, but this path has a clear problem of unsustainability within it. Hopefully MM has something planned for this or KAG will face the same fate as some indie games that were promised to be more than what they turned out to be because of the failure to foresee this issue.