Home at last, thanks again for the responses and questions, because I'm still so early in the world building stage they're all very much welcomed. :) I have put quite a lot of thought into how magic will interact within my feudal setting as well as how to prevent it from being too disruptive without just hand waving the problem. I'm going to ignore imbuements for the purposes of this discussion, because all it can do is allow combatants to perform difficult or otherwise impossible feats via magic. It will have an effect on the tactics used within the setting, but will be rare enough to be the exception rather than the rule. When I started putting this setting together, I was aware that incantation, sorcery and magic as advantages being free form would cause issues. I feel it is worth breaking these apart and discussing them individually, but there are a few universal "truths" that I intend to apply to the setting, which will mitigate the effect to an extent. 1) Magic is rare. Magic is trait that only a small number of people are born with. Not only that, but most people who are born with the ability to use magic have only a very weak talent and will never become capable of manifesting anything but the simplest of cantrips. One example of this would be a person with a limited version of the imbuement talent, such that they can learn only one imbuement skill. 2) Most people are serfs, villeins or slaves and are therefore uneducated, worked tirelessly and are of intrinsic value. There are no grand academies or schools of magic, because the vast majority of people who are born with the ability to use magic are of more value to a lord as a farmer or shepherd than they would be spending a few years of their lives (at his expense) learning to control their meagre talent. 3) Magic is unreliable. When a spell critically fails, it does so in a spectacular fashion proportional to the amount of power invested in the spell. A farmer who critically fails a daily farming roll might damage his crop slightly, or fail to spot an infestation, but he is very unlikely to accidentally blight his lands. Therefore, the only people who will ever likely be trusted to use their magic in a way that would have any significant economic impact are the people who are so skilled as to be very unlikely to fail. These people will obviously be of great value and likely able to demand a king's ransom for their work. They will also want to rock the boat as little as possible, lest they do eventually have a critical failure and find themselves in trouble. This at once makes skilled and reputable magic users valuable and desired, whilst rendering unskilled (or just unlucky) magic users something to be looked upon indifferently when they ply their trade in a manner unlikely to be catastrophically harmful, or reviled after they an entire harvest crop to fail! 4) Magic is never free. Generally the cost of casting any given magic spell will be one that the caster is willing to pay and that will have no appreciable effect on the campaign setting. Casting a spell that creates a fireball might reduce the ambient temperature, or consume a token amount of fuel - neither of these costs are going to prevent a user of incantation magic from throwing a fireball. But as spells become greater in their scope, in their ability to fundamentally alter the campaign setting, their associated costs become less bearable. A spell that might alter the makeup of the soil in a field might enhance the harvest one year, but would draw so many nutrients from the surrounding soils to the surface as to ruin the field for the next ten harvests. There will also be certain spells and powers that are just flat out impossible, though that will not stop people trying, such as attempting to turn lead into gold or summon valuable raw materials from thin air. Obviously there are a lot of ways to use magic indirectly in order to earn money, such as using magic to scry for the location of valuable metals and then move the earth to open a passage way to them or draw them directly to you. But this would require a lot of skill, a lot of time and a lot of luck. Once the metal was found, a lord would likely find it cheaper to simply employ hired labourers to erect a mine. 5) Magic cannot replace skill. Ignoring the homing magic arrow and quite a few other possible interpretations of that sentence, this truism implies that a magic user cannot replace years of knowledge learnt the hard way. While a magic user could take a lump of raw iron and transform it into a suit of armour in a fraction of the time it would take normally, the end result would be a lumpy, uneven, brittle mimicry of a well crafted suit of armour. The only way around this is for the magic user to themselves learn what it takes to make well crafted armour themselves, to gain a high enough skill in the relevant armoury or crafting skill to offset the intrinsic penalties that incantation magic applies for creating anything other than raw materials. In order to enforce this I will have to remove the ability to use bestow bonus to offset the penalty. As with any limitation, there are ways around it, a magic user could borrow or steal the memories and skill of a master smith, but likely at the cost of slowly weakening those memories and skills over time - not enough for it to be an issue in times of great need, but enough to prevent it being desirable. 6) Most people just aren't great, they're just good enough. This truism doesn't just apply to magic, but it has perhaps a greater impact on magic due to the high character point investiture required to be able to do anything noteworthy. The player characters will likely be exceptional, brighter, stronger, more skilled and luckier. Not so much that they will be necessarily instantly recognised as such, but in all likelihood their abilities will grow far beyond the norm. Next, I'll break down the individual magic systems and how (I hope) I've compensated for the worst ways they could affect the campaign setting. Obviously they will have a fairly profound effect, but that isn't a bad thing. I fully expect lords who are rich enough to employ users of incantation magic to auger the location of their enemies forces, just as I would expect those same enemies to employ their own magic user to foil those attempts. Incantation Magic is already limited in several profound ways. It cannot affect control the minds of animals, nor can it affect the weather in any meaningful way. It cannot control, summon or interact with world ending creatures from beyond the boundaries of time and space - perhaps a little bit of a niche limitation, but one I quite like. It does not allow for gates, teleportation or any other form of transportation magic. If a magic user wishes to get from point A to point B, they must walk there or transform themselves into a sparrow and fly, running the risk of being permanently trapped in that form should they critically fail casting the spell, perhaps. But most fundamentally of all, it can neither heal the living nor effect plants in any way other than indirectly. I still need to trawl through the rules to try and find anything that could drastically upset the campaign setting, but I think they've caught most of it themselves. What little is left would require the caster to be so powerful and highly skilled that they could likely rule the world if they so chose. Sorcery is probably the most likely form of magic to cause me issues, because it is less prone to spectacular failure and has fewer inherent mechanical restrictions. As such, I will be much more careful in what I allow and what is prevalent amongst none player characters in the campaign setting. I haven't yet decided if I am going to include it in the game at all, but I do quite like it and probably will. That said, I am most likely going to only allow it to be taken with limited scope, i.e. sorcerers who are either gifted with the ability to control of a particular element or another thematic set of powers. It will also be found more rarely than incantation magic. Priestly will be a form of magic as advantages. I haven't fully determined how it will work, but it will likely have a combination of the limited uses per day, pact and unreliable limitations to represent the fickle nature of the gods and their followers. If there is a better implementation of this already written in a Pyramid article or source book, then I have yet to find it. The nature of the advantages that can be chosen will also be limited by the portfolio associated with each deity, which I still need to write. Druidry will cover pretty much everything else. It will also be a form of magic as advantages and it will allow the control over the minds of animals, plants and the weather, but it will also come with a pact limitation requiring the druid to uphold their vows to nature. Their magic will not be "free" either and therefore they will not wander from village to village massively enhancing the growth of crops as this would lead to a ruinous famine in years to come. It too will likely have some form limitation such as limited use, the requirement for preparation or simply a fatigue cost.