D&D 5E What high-level spells could warp society?

[TwoSix]

Some house rules I'm planning in implementing:

1) True polymorph can only be maintained on one target. If you cast true polymorph on a second target, the first target reverts to their natural form.
2) A simulacrum is not a valid target for a True Polymorph spell.
3) A simulacrum cannot cast any spell of 6th level or higher. If the simulacrum has spell slots higher than 6th level, those slots can be used for upcast spells.

 

[Baron Opal II]

I've created a spell duration of "enduring" for some spells like continual light. While the spell is active you dont get it back.

There are ways to get around that with appropriately priced foci that you cast the spell on instead, but the cheap way locks up the spell until it is dropped.

 

[Baron Opal II]

I think Jester had an adventure where simulacra started cascading.

 

[tetrasodium]

This is semi-explicit in my campaign. The availability of alchemy, kindly grandmothers, and hedge wizards allows for an infant mortality approaching modernity. However, there are monsters out there, and excess population looking for some easy wealth heads out to cull the monsters. Which, amazingly enough, culls the excess population. But, some make it back. This creates stories that inspire the third sons and daughters. And the cycle repeats.

I think that we are talking about different ends of the spectrum on how magic warps a setting and what kind of magic it takes to support that.

My post was overall about how magic and the vested interests of powerful individuals keeping their power by using magic to force medieval stasis on the powerless below them even with generational turnover. Yours is more about the people at the bottom engaging in self culling to avoid overpopulation without breaking trade as a plausible thing... But I think that you are missing a few steps needed to maintain it.

Without island geography or some other bit of societal/environmental pressure pushing back against civilization to encourage the anti-population growth like you described it breaks trade by making the wilderness between towns too dangerous to ever travel. Unless the inhabitable world is a chain of islands that makes expanding the village impossible, it's almost certainly more desirable for the people at the bottom to just clear more wilderness over there and keep growing a little at a time -- unless you add a source for monsters that make that expansion implausible like the nobles I described or something like wuxia/cultivation fiction style beast waves that grow nonlinearly in power as the local civilization does in scale.

 

[SkidAce]

Without island geography or some other bit of societal/environmental pressure pushing back against civilization to encourage the anti-population growth like you described it breaks trade by making the wilderness between towns too dangerous to ever travel. Unless the inhabitable world is a chain of islands that makes expanding the village impossible, it's almost certainly more desirable for the people at the bottom to just clear more wilderness over there and keep growing a little at a time -- unless you add a source for monsters that make that expansion implausible like the nobles I described or something like wuxia/cultivation fiction style beast waves that grow nonlinearly in power as the local civilization does in scale.

I like beast waves versus civilization.