I am sure that anyone who wants to start or even if he is already active in buckler and sword study, will ask himself the one million € question: “What is the right buckler???”
So.. what is it? If we look at original examples that had survived, or if we look at drawings in manuscripts or printed books from the past periods, even an outsider can quickly understand why all the confusion. There are so much variations in shape and size that it makes us go mental being so much used to our modern, reach-me-down, way of life.
But fear not, things are simpler than they look! The answer of the right size and shape is embedded in its user size and the choice of sword and buckler tactics. When people ask me this question in person, I give the following suggestion:
Start with the buckler diameter of 10 inch / 25 cm. This should be the base. It is the double length of measurement from center of palm to end of middle finger of an average grown up man (If you are tiny or huge, you should adopt accordingly).
Now as you know the base size, we can add or subtract the diameter accordingly to our preferred tactical doctrine. This means that if we are into aggressive tactics which focus on ending with grappling, then size should be subtracted as it will be easier to maneuver our buckler. If we are the type who like to stay at wider measure, then we should increase the diameter. However do not go crazy going up or down. Start with changing diameter steps of 2 inch / 5 cm.
If you are just starting in buckler and sword art or are not crazy about any extreme end of tactical doctrine, stay with the size of 10 inch / 25 cm.
That covers the diameter of our holly buckler but what about the shape of it? Should edge be flat, convex (buckler edge slanting toward you) or concave (buckler edge slanting out toward opponent)? As bucklers are small, there are only two choices to pick from: flat or concave. The reason is that convex edge will work against you for intercepting enemy thrusts. So be pragmatical, as were our ancestors, and use concave if possible. It may look odd and unnatural having such strange contraption in hand, but it is much more stable in action than the alternatives.
Good job my brave knight! You have completed your quest and are rewarded with secret knowledge of buckler design! You have received fighting skill bonus: dexterity +18 and agility +10! Congratulations! :)