So a question that often pops up when considering a dnd world is: How rare are adventurers? How easy is it to get access to a 4th level spell? Would casters producing 3rd level magic own the economy of this world?
DMs for the most part handwave these questions, which is fine in the vast majority of games. However, if you like to be more detailed in your world, than this Excel could be of help to you.
That's a cool exercise and it would be really interesting to see a setting that is self-consciously built around a set of class demographic assumptions--in the way that, for example, Ptolus or the
Tippyverse are self-consciously built around game mechanical assumptions.
And, notably, there are some cool details that the example that you posted pics of (btw, thanks for that; I'm always leery of downloading files). The highest level wizard (& sorc, & lock) in that simulated world is 15, which means that no one represented in the chart can cast a wish spell.
You
could, of course, decide by fiat that someone does cast the wish spell, but the far more interesting exercise is to start with reasonable assumptions and then be pleasantly surprised by the idiosyncrasies they yield--maybe in that world no wish spell has ever been cast... yet.
The problem with the tool--and first principles worldbuilding in general is that we often want self-contradictory nonsense societies from our D&D, in which demographics, land area, and implied technology render medieval aesthetics sensible only in the context of capriciously feudal-chic Kirbyesque space gods. The far safer tactic for systematic worldbuilding is to start with the content one wants it to have and then reason backwards to the adventurer mortality assumptions as an exercise in intellectual curiosity.
So for example, I could change the base assumptions to the following, since it feels like it'd get me closer to the wish spell availability I want:
For progression, I would assume a large die-off in the earlier levels but after a point it would be progressively more likely to survive to reach the next level. A 12th level mage is very likely to become an archmage if she can live long enough. [...]
Could you re-run your spreadsheet with a progression rate of 90% after 5th level?
But wait that's 128 level 20 archmagi (625*(0.9^15) (...I think)), that feels like too many (
esp. considering the last time that our world had a population of 100,000,000, it was 500 BCE). Let me just tinker with the numbers a little more...
Some people may prefer this method. In this chart, I am using the 5e XP table to determine rarity. For example, it takes 300 XP to reach 2nd, and 900 XP to reach 3rd.... so we assume 3rd level characters are 1/3 as common as 2nd level characters.
The only trick is at 1st level, as there is no XP number. So we don't know how much rarer a 2nd level character is from a 1st. Therefore, I left that as a user defined value. In this chart, you can set what % of 1st level specialists that actually advanced beyond 1st. Then the chart will handle the rest. All the other features are the same, this is just a different way to determine level rarity.
Example: If you think that 70% of your 1st level specialists stay at 1st level for their careers, then set the value to 30%.
Again, potentially interesting if carried to its conclusion but, at bottom, D&D rules do not simulate life. I think it would be hard to use these calculations to add texture and detail to a world without also creating a bunch of odd knock-on effects.
The fun here is in discovering the novel and very likely gobsmackingly jank-ass D&D world that would exist if those premises were fully accepted (again, see Tippyverse).
Would casters producing 3rd level magic own the economy of this world?
I feel confident that it's the casters producing 2nd level magic that would own the economy of the world.
Rockefeller started Standard Oil to meet the world demand for illuminants--the money printing machine that was late 1800s access to light.
Any business with a sufficient number of assembly-line working 3rd level wizards to cast continual flame would be a world economy spanning juggernaut--producing safe, infinitely durable, clean burning, moderate intesity light, far technologically in advance of anything that yet exists. At least until they saturated the world market with magic candles, causing a global market crash... or they used up the world supply of ruby dust.
