Everything you think about Game Mastering is probably wrong: Part IX - The Biomagnification of Magic
There are a lot of different discussions between how to run a high fantasy versus low fantasy campaign, and the reality is all games with magic will end up as high fantasy eventually. It merely becomes a question of how quickly do you want that to happen. Why is this such a predestined event you might ask? Because of the biomagnification of magic within a campaign.
Biomagnification is a term more commonly used to discuss the dangers of pesticides in a food chain. A tiny bit on the plants, which are eaten en-masse by small animals who then have a little bit in them. The foxes, ferrets, and other smallish animals eat a bunch of small animals and develop a notable amount of toxins. Then large predators eat the foxes, ferrets, and the like and suddenly have dangerously large amounts of pesticides in them, enough that it would be toxic to try and eat those large predators (who will eventually die from the toxins). This is how magic works in a campaign that goes on long enough.
When I played a DCC campaign of linked modules, I found each individual adventure pretty good. Unique magic items and weird effects abounded, it was great. The problem was that each adventure had at least one unique oddball item, often two or three. After a dozen adventures, we were awash in not only the abilities of levelling up but in dozens upon dozens of weird magical items that we could combine in unpredictable ways. Nothing was ever solved with rope, levers, or torches any longer. We were Rhialto in a flying castle rather than Conan with a steel sword and iron thews.
In the early days of Google+, the event that made it the modern era Bell Labs of RPGs was ConstantCon/Flailsnails. A hundred GM’s all running pick-up OSR games that people could just mill through. There were casts of famous adventurers and a myriad of interesting campaign settings and more than a few TPKs. The TPKs were good, it was the near TPK s that were the problem. Each GM had their own weird quirks to their setting (as well they should), and players slowly gained magical doodads and baubles. Even weird curses could be put to use in the right situations. When there was a near TPK, the surviving player would collect all the magic items from the dead. Biomagnification of Magic.
Suddenly there were specific characters that roamed through low fantasy campaigns like badly written superhero satire. Rings that turned slugs into dragons, potions of polymorph house (that one was me), swords that auto-killed anyone wearing blue clothing, and a myriad of other interesting items that in isolation were great. But even “standard” magic items become a problem when condensed to such that a level 4 character has over a dozen of them. Tougher encounters to compensate only cranked up the high magic nature and furthered the biomagnification among the survivors. ConstantCon slowly died as people stopped having open tables and returned to closed campaigns. Players still bounced between campaigns, but characters didn’t. But even still within campaigns I’d note that the magic involved builds up.
For a half a decade or so I’ve been running a series of linked games (a generational game) where there are potent science fantasy elements in the deep background, but the games always focus (at first) on the day to day grind. It is beyond low fantasy. In this last campaign the first twenty or so sessions were all about trying to get a stable food supply and getting such high tech equipment as “a sack of rocks the right size for throwing” and “a wicker shield”. But the odd bit of real treasure would sink in such as a spell, or a magical sword, or the location of a magical lemon tree. Usually only a little bit of magic acquired at a grueling cost with dubious uses. By the last session though we have high level characters assembling all their goodies in a chaos engine to thwart the science-fantasy menace with its own bag of goodies. We have swarms of orcs and bird knights fighting undead ballista teams. A psychic robomech with a lightning sword shrugging off the flames of a hell dragon while a wizard piloting an ancient hover tank retrofitted to try and turn The Dark Crystal into a gun fires it off as a Wand of Wonder at a swarm of Giant Swans. All the while a melange mutated PC gets into a clairvoyant psychic showdown with an Elven Archmage amidst a series of magical energy draining pillars. Several portals to hell and a set of teleporting power armour were also involved.
This level of high fantasy is wonderful as an end cap (or near end cap) of a campaign, because it stops being sustainable. It's not that the game stops working, it's that it strains the sense of immersion to have there be many credible threats available to challenge the players in a low magic setting at this point. The same low magic feel that made it so satisfying when the players pull off assembling all the various nigh-useless doodads and cursed artifacts into a well oiled death-dealing machine also puts a countdown timer into play. There might be a few more threats that could stop them, but likely it will quickly snowball into a phase where they just dictate the new world order. Which is fine, but its better to switch that to a bit more of a narrative style where they explain how things will be with a few odd rolls to see if it goes perfectly according to their plan. It then moves to become time to start working on the next campaign as these characters retire.
What does this mean for you as a GM planning a setting? The difference between “low fantasy” campaign and “high fantasy campaign” is really just a gas pedal for “how quickly do we get to high fantasy nonsense” and you should try to pace the amount of magic available so that the maximum level you are aiming for is hit before the “gonzo high fantasy” barrier is breached. With NGR’s XP structure and level limit of 10, I try to angle this to be that something capital W “Weird” is found every second or third adventure. This isn’t some scripted metric, I run sandbox games so this is more about how much and how densely I stock Weird things in the hexes. I also allow for a lot of randomness in where things are with the expectation that sometimes you might go 5 games without anything Weird and sometimes you’ll get 5 at once.