I've read a few good posts the past few days on running a minimalist "low magic" fantasy RPG campaign with a rule set such as Swords & Wizardry and I couldn't help but think to myself: Isn't bog standard classical D&D (and as such Swords & Wizardry) already Low Magic when magical healingis considered?
As it was (or is depending on your rules) a Swords and Wizardy campaign and Original D&D campaign starts out Low Magic with very limited magical healing, so limited there's none at all without the DM bending the setting to give players extra access to healing magic; clerics have no healing spells available to themsleves at 1st level and Magic-User are walking about with just one spell to their name and it's healing no one at all.
It' a good long time measured in experience points earned before healing spells become frequent. A cleric gets one at 2nd level: one cure light wounds spell after earning 1,500 xp. Eventually there could be a whole 2 cure light wounds and 1 cure serious wounds spells on hand per 6th level cleric after the successful accumulation of 30,000 experience points. That's not a lot of experience points and still not a whole heck of a lot of healing magic for a party of adventurers if there is only one cleric per 4 to 8 other adventurers. That's a total of 4d6+4 pts of healing, in 3 spells, that 7500 exp per d6+1 of healing is that really enough to define an entire style of play?
The rules as written Swords & Wizardy (and original D&D) are already a low magic setting when measured in healing spells with a fairly standard starting party. Sure as the campaign rolls on there will be more and more magic items. Out of every 1000 GP worth of loot earned there will likely be at least 1 healing potion .... maybe.
What are the odds of finding a randomly placed (rules as written) healing potion in S&W? Not so high really. For every 100gp worth of treasure there is a 10% chance of trading that out for a roll on a tabel that provides a 5% chance of getting a minor magic item, 25% of all minor magic items are potions, 36% of randomly determined potions are healing potions of some sort; there's a 0.045% chance of finding a healing potion instead of 100 gp. A cleric has about a 0.5% chance of discovering and keeping a healing potion by the time they reach 2nd level.... that's not a lot of magic healing.
By the time a cleric earns 30,000 exp there will have likely been 21,500 gp worth of loot discovered. If 10% of that is swapped out for better loot and 5% of that is magic items with a 25% chance of a potion and 36% of potions are healing potions of some sort that's (215 x .1 x .05 x .25 x.36) a 9.675% chance of discovering a healing potion between 1st and 6th level. Not a whole lot of magical healing there at all is there?
Add in scrolls and the odds of finding healing magic increases a lot. Those 21,500 gp worth of loot will likely include 1/2 a scroll with a chance of under 12% that scroll will be a healing spell. Still not much magical healing going by the rules as written.
In consideration of the rules as writtne Swords & Wizardry (based on S&W Core Rules) is a Low magic setting when access to healing magic is considered. If there is more healing available it is by DM fiat and clever play.