With any martial art you have to practice as realistically as possible to get the maximum understanding of your art. Ideally, you would actually fight life-or-death with real equipment against an opponent who was actually trying to kill you in order to really learn your art. Of course, in our modern day and age this isn’t possible, so we have to try to come as close to that as we can and accept the shortfall as the price of living in a peaceful age or location.
There are three primary ways of making practice safe enough: Using “safer” weapons, wearing protection on your body, and reducing the danger of your actions. Unfortunately, all three of these practices reduce the accuracy of what you’re trying to do. Safer weapons usually handle nothing like the real thing, protective gear on the body limits motion and prevents you from moving as you should, and changing the way use your techniques obviously limits the reality of what you’re trying to do.
Students of the Japanese sword found themselves in a dilemma when peace became the norm in feudal Japan: there was no way to easily test themselves and their art, so as a result they began to search for ways to practice more safely. First they replaced their steel swords with wooden swords (as much to protect their valuable swords during practice as for safety), but they discovered that wooden swords are almost as lethal as steel. Then they created shinai; strips of bamboo joined together to form a flexible rod. These were fairly safe, but still caused some damage, so partial armor was added to the mix and the modern sport of Kendo was created. As anyone who has studied Japanese swordsmanship will tell you, however, Kendo bears very little resemblance to real Japanese swordsmanship. In one sense there’s nothing wrong with this, of course: Kendo is a wonderful sport enjoyed by many. But for those of us trying to recapture the essence of a lost art it’s not a meaningful approach.
Modern students of der Kunst des Fechtens (the art of fencing) face the same dilemma the Japanese faced; indeed, something of the same problem was acknowledged in late-period Germany. Schools of martial arts drifted away from Ernstfechten or “fencing in earnest” until all that remained was a martial sport called Schulfechten or “school fencing” (Schulfechten had existed beside its more martial cousin all along, but now it was all that remained). Schulfechten training involved blunted swords and they changed their art to forbid the use of the thrust and to limit the more dangerous grappling techniques (e.g., joint breaks) for safety’s sake. Even so, these limitations still left an art that is too dangerous for today’s sword students (surgeons made a good living sewing and splinting the injuries of a day’s bouting in historical fencing schools), so we see them taking the same route that the Japanese took: Instead of steel or wooden longswords, they fence with shinai that have been modified by the addition of crossguards and pommels to simulate European longswords and they add protective equipment that limits their movement more than true longsword fighting would have. As a result, I fear that modern longsword practice may become no more than Kendo and lose completely the tenuous connection we’ve been building with the lost arts of our ancestors.
Fortunately, however, students of Harnischfechten are in a somewhat better, although still not perfect, situation. Wearing safety equipment in armored fighting is not just a necessity of safety, it actually makes our practice more realistic. And while we haven’t yet come up with realistic metal training weapons that are safe to use as simulators, we can still make some pretty acceptable ones that, when combined with good armor, will allow us to fight at almost full speed and power.
Getting accurate and realistic armor, however, is problematic. The simple fact is that the vast majority of armor available today is so incredibly bad that it in no way simulates the way the real thing worked, nor does it provide the necessary safety. This means you really have to work hard to find an armorer who not only claims to be making highly-accurate armor, but who really is. Moreover, the armor has to match the kind of fighting you’re doing: Wearing the harness of a 12th-century crusader will in no way teach you anything about how armored duels were fought in the period of the Fechtbücher.
Assuming safe, realistic gear, all that remains is to put it into play. To do that, however, you have to know how it was used and create a rule structure for your bouts that adequately reflects actual practice and, at the same time, rewards historically-correct actions and punishes inaccurate ones (by which I mean the rules make it impossible to win a fight by resorting to inauthentic techniques). Most strikes are ineffective, and thrusts have an effect only to the openings between plates; even then, thrusts must be done differently against a gap in the plate covered by mail (e.g., the armpit) than they are against a target with no mail (e.g., the palm).