Traditional medicine is medicine as it was (and often still is) practiced before the advent of modern-day, scientific medicine. This category can also be taken to include esoteric "alternative" measures such as mesemerism and homeopathy which aren't really old enough to be considered "traditional".
If your campaign is set in an era before the rise (or after the fall) of scientific medicine then "traditional" techniques are all there is. For a campaign in which magic is a reality, "traditional" techniques may parallel or include those used in magical healing - it probably does more for the verisimilitude of your campaign world to have your magical healer drive out a poison by acupuncture or manipulating your chakras that it does for them to zap it out with some Vancian insta-heal. In an early modern setting they might use an alchemical wonder drug or use mesmeric science to correct the flow of your electric fluids.
Generally the deciding factor as to whether a medical technique is "traditional" or "esoteric" or not should be the basis on which it is administered - if it is administered on the basis of science supported by evidence1, it doesn't qualify, but if it is based on practice without theory or unsupported theory it does.
An indicative list of traditional and/or esoteric techniques would include:
- Vedic Healing - more a complete system of medicine than a specific technique.
- Faith healing - which may equate to theurgy in some settings.
- Astrology - strictly, this was used as a diagnostic tool and to determine correct treatment methods.
- Humeral Therapy
- Psychic surgery
Obviously the boundary between some of these techniques and magic can be slender at best - and of these, some have demonstrable biological effects, some rely on the placebo effect and some are, at best, still open for debate.
Most of the truly harmful or ineffective treatments tend to have been weeded out over time, but there is little evidence that any of them are noticably preferrable to scientific medicine in general use.
Game and Story Use
- Every fantasy adventurer should be subjected to "folk remedies" at least once in his career, especially if they are really embarrassing.
- Game masters (and enterprising player characters) should also remember the quips about "herbal medicine" in the various Discworld novels - basically, adding a few weeds to anything drinkable will somehow make it seem much more trustworthy. Build on that, and then watch the results with amusement.
- As noted above, most 'fantasy adventurers' should be treated with nothing but "folk rememdies" and magic; the proportions of each to be determined by the setting.
- In a modern setting, a strong attachment to - or intolerance of - "traditional techniques" makes for interesting characterisation.
- PCs may find themselves up against a traditional healer in some settings - possibly one who is doing more harm than good to someone they need to help, but who may have an important socio-political hold on their host community.
- An NPC with a noticably effective record with one of these therapies may be an interesting mystery, especially in a low/wainscot magic campaign - perhaps they are using healing magic as well as or instead of their purported discipline.
- In a fantasy/magic realism campaign, these techniques may work and be part of mainstream medicine.