Players of games that take place in a pseudo-medieval fantasy world will inevitably ask the question “well, can’t we just invent our way out of the problem?” and start trying to figure out how to introduce guns, steam engines, or flying machines into the world. The contents of this page are why those ideas won’t work, at least not in the world of Veilguard.
The title of this page may be a bit misleading — the technologies discussed here are forbidden to players, not to their characters. The world itself has reasons why these technologies haven’t been developed, and only a couple actually have anything to do with something being “forbidden.” On a meta-level, however, the GM team doesn’t want players to start trying to inject modern ideas and technologies into what is at its core a fantasy game, hence the label of “forbidden four.”
Steam is an element, just like water and fire, but it is a hateful one, lashing out at everyone and everything nearby. It is possible to contain it, temporarily, but doing so makes it even angrier, to the point where it will eventually and without fail rupture the thing containing it. Pressurized vessels, even ones with a means for the steam to escape after it reaches a certain pressure, must be allowed to fully cool back to room temperature after less than an hour of use, or risk the steam within growing a malevolent sentience and tearing them apart.
Tea kettles and alchemical apparatus do not generally have enough volume to create a Steaming Spirit in this way, but the few attempts at putting the easily-observable power of steam’s expansion to real work have all, without exception, failed spectacularly after a Steaming Spirit awoke and destroyed the engine. Plans for crude steam engines surface every few decades, as bright inventors come up with the idea all over again, but they are quickly advised to not attempt to create such devices, as the consequences have often been fatal for anyone in the vicinity when the steam’s containment inevitably fails.
The world of Mundus was created out of nothingness by the Old Gods, and shaped by them to fit their eldritch needs and imaginations. The “geologic record” (such as it is) is more along the lines of a procedurally-generated Minecraft map than anything a real-world geologist would recognize. There are no large deposits of oil to be found underground. Coal seams were added to the geological mix by the Old Gods because they knew it was necessary for some industrial and metallurgical processes, but they didn’t see any need to add in underground petroleum or methane to their world.
While it’s possible to use other flammable liquids besides petroleum to create an internal combustion engine, it’s prohibitively expensive. That cost-benefit threshold has made it very difficult for the few inventors who have tinkered with the idea to make anything besides mechanical curiosities. The ideas necessary for a crude internal combustion engine exist — but nobody has bothered to do much with them, because the effort and expense necessary to make a workable and reliable one using the fuels that are available is astronomically more than the value of what that engine would be able to accomplish.
Just as steam is an element, with its own means of manifesting sentience, lightning and electricity too can turn into a Spirit, and just like steam they detest being contained or put to work. Lightning seeks to strike, and then return to the Aether; mortals harnessing it to do their bidding has always been an uphill battle, one which becomes truly dangerous and nearly impossible at the levels of power that we in the modern nonfiction world are accustomed to.
The means of generating electricity as we do in the real world, principally the act of spinning coils of wire within a magnetic field, is known to the people of Mundus — they just can’t make much use out of it. Generators that produce any more electrical power than is needed to power a flashlight tend to become inhabited by minor Lightning Spirits, which constantly seek to escape the confines of their housing. Anything strong enough to power an oven immediately shorts out, as the Lightning Spirit within is powerful enough to burn through a spot in the insulation around it and escape. Larger generators have been built as experiments, with incredibly elaborate containment fields, but all that results is a slagged generator and a very annoyed Lightning Spirit trapped in the equivalent of a magical cage.
Storing electrical energy via chemical batteries is possible, but only in small amounts. Batteries over a certain kilowatt-hour amount (more easily measurable in watt-minutes than kilowatt-hours) tend to short out and release their charge into the surrounding air — the current theory is that the energies contained spawn a horde of tiny Lightning Spirits that then immediately flee into the Aether. The idea of a capacitor is completely unknown; such devices have never reliably worked, their charge immediately dissipating (usually into the nearest mortal) rather than remaining in the capacitor. Combined, this has made it altogether easier to use stores of magical power to generate electricity when it’s needed, rather than using anything engineered based on scientific principles.
One example of such a device are “lightning mines,” developed by Tomarran Gazelles as a trap for use against large predators or enemy scouts. Disposable generators are set up with a magical power source, designed to rapidly convert that aetheric charge into an electrical one, and then immediately release the resultant Lightning Spirit in the direction of the enemy. These weapons are bulky and difficult to transport, and their one-shot nature, relatively short range, and complete lack of an ability to reliably aim the conjured elemental leaves them relegated to the role of heavy-duty anti-personnel mines, rather than battlefield weapons.
The recipe for black powder was discovered a millennia and a half ago, and it was promptly forbidden for those who knew it to teach it to anyone outside of a very select list of trusted alchemists. The powder is notoriously sensitive to fluctuations in the aether around it, igniting for no apparent reason and without any reliable way of predicting or preventing the explosion. (It’s thought that it was discovered at least three times prior to it’s “official” discovery, but that in each of those cases it blew up its discoverer along with all of their notes.) This has proven true for all other conventional (i.e. nonmagical) explosives that have been discovered in the centuries since.
Though a ritual circle was eventually developed that isolated and stabilized the aether within it, allowing for black powder and other aether-sensitive materials to be experimented with in comparative safety, the expense of maintaining such an array is exorbitant. Further, the array cannot be moved — it depends upon a solid, unmoving substrate to function, making it impossible to use it to help transport explosives safely. This has led to a general attitude that, while there might be a use for black powder, it’s altogether more trouble than it’s worth, and so it has been relegated to use as an ingredient in some particularly hazardous alchemical recipes. Most governments and alchemist guilds try to keep the recipe under wraps, just to stop people from trying to whip up some black powder and blowing themselves or someone else up.