A typycal question from many DMs is:
"How can I run a low magic campaign (or where magic is rare but very powerful) in D&D?"
The answer is not simple because D&D is a game where magic isn't uncommon nor "rare but very powerful".
Magic, instead, is so common that the Barbarian is the only class that can never access to spellcasting.
Whatever adaptation you'll choose, it wouldn't fit 100% for the standard game.
To whom asks me about low magic campaigns, my first answer is "Is it only the setting that must be low magic, or PCs must have limitations too?"
If you're concerned only about the setting, then my solution is very simple:
Just assume that in your campaign spellcasters and magic items are very rare.
The PCs are exceptional individuals and their use of magic reflects that uniqueness.
Mundane world can have mixed reactions in such campaigns, for example:
- laws can forbid or limit spellcasting in urban or civilized areas
- spellcasters are controlled and registered. Those that elude these controls are outlaws.
- common folks are automatically hostile towards spellcasters.
- when spellcasters interact with common folks they have disadvantage on their Charisma checks.
- witches' hunts or hostile actions towards spellcasters are regularly organized by public authorities or violent riots burst out from the population
A different approach is requested if you want limitations to your PCs.
I'm not very fond of such option.
A rule of the Good DM is
Any forced limitations to PCs is a DM's defeat.
For me, some lightly limitations are:
Gritty Realism from DMG
As their rests will take longer time, spellcasters' precious slots will recharge at a slower rate.
They'll think twice before to cast a 1st level spell or higher because they'll fear to run out in a short time.
Troubles between PCs and NPCs
Just use what written above regarding interactions with NPCs or laws from public authorities.
Magic Items
Thanks to bounded accuracy, D&D 5e can be played at high levels with very few magic items.
Keep a rigid control on their distribution, increasing their rarity, preferring single use ones such as potions and using the optional rule of charges from the DMG for the others. Once they run out of charges they lose their powers.
For extra difficulty you can choose not to reveal the number of charges left.
If you're still not satisfied by these options, you can choose these heavier ones:
Cantrip
If you believe that infinite cantrips are "too high magic", give them slots too, using the same rules of recharging of normal slot.
I can see three choices :
- cantrips' slots number is equal to the number of known cantrip.
- cantrips' slots number is equal to spellcasting ability bonus plus proficiency bonus
- if you use the optional rule of spell points from DMG, than a cantrip is 0,5 point
Material Components
All components are always consumed when the spell is cast and cheap components cannot be replaced by Arcane Foci or Holy Symbols.
PCs will have to keep track of components, without them they wouldn't be able to cast spells.
High Level Spells
You can rule that in your world higher level spells are hard to cast.
For example, anytime a spell is cast with a 3rd level slot or higher, the caster must succed in a check with DC 8+slot level.
The caster roll a d20 and adds her spellcasting ability bonus and her proficiency bonus.
On a failed check, the caster couldn't channel enough magical force, the spell fades away without effects and the slot is lost.
Multiclass and Feat
They're already optional rules (though largely used) but you can rule that spellcasters cannot multiclass or non spellcasters cannot take the Magic Initiate or Ritual Caster feat.
With this limitation you'll prevent some of the most feared (not by me) combos.
Spells Limitations
Simply, in your world some spells are unknown or not revealed by gods.
Make a list of those spells and give it to the players during Session 0.
Class Limitations
You can ban from the game some archetypes such as the Eldritch Knight or the Arcane Trickster or you can swap the regular Ranger with the Ranger without spell from Unearthed Arcana or you can rule that paladin's slot can be used only for the gli slot Divine Smite feature.
You can also ban entire classes, but I strongly advise not to do so.
Conclusion
I hope that these advices would help you to shape your game.
But when you're starting to plan a low magic campaign, ask yourself the same question I ask to whom seek counsel to me
"Why do you want a low magic campaign?"
If your first answer is "Because I like worlds with low magic"
Then I have a second questions for you:
"What don't you like of D&D's magic system that you need to modify or restrict It?"
And provocatively I have a third question:
"Why is much more common that people ask me about low magic campaigns than about a world without warriors or rogues, or about a world where magic is so common that people normally live in skyscrapers built on clouds?"
In following posts, on this blog, will investigate about these motivations
Bye.
The DM.
