Background: Hnefatafl is often called "Viking Chess" -- it was *the* popular strategy game in northern Europe during the first half of SCA period, before Chess moved in and occupied that memetic space. There are a number of versions of it, but they are all believed to involve a force of a King and N men (the "Swedes" or "Defenders") who are being besieged by Nx2 opponents (the "Muscovites" or "Attackers"). The Attackers are trying to capture the King; the Defenders, to get the King from the center of the board to the edge or corner. (I tend to refer to this whole family as "Tafl games", although this is simply a shorthand.)
Despite being popular for centuries, across most of northern Europe, there exist no really good descriptions of the rules. The best one we have was written by Linnaeus in the early 18th century, when he was visiting Lapland, the one place where Tablut, a version of the game, was still being played. He wrote down the rules in Latin, and we've largely been working from his notes ever since.
This article is based on a simple but important premise: that the standard translation of Linnaeus, which everyone has been using for the past century, kind of sucks. It left out key passages, mistranslated a few details, and generally wound up being a bit misleading about some of the critical details. That's important, because everyone who has played Tafl has noticed that it's pretty poorly balanced. For decades, folks have argued about how to tweak the rules to be less broken.
So this article is quite welcome. It is by no means the last word on the subject, but it seems like a principled and careful reconstruction. John Ashton, the author, presents the rules largely as translated from Linnaeus; further down, he goes into a lot of detail about what he's interpolated into those rules and why. While I'm not certain whether he's correct, his logic sounds good, and (not having tried it yet, mind), the reconstruction sounds better-balanced than average.
I recommend reading the full article, but in short, he presents two critical tweaks to the usual rules. First, the always-contentious rule for capturing the King winds up sort of in-between -- it requires four captors when he is on his "throne", three when he's next to it, and two otherwise. This makes the King less immortal than in versions that always require four captors. Second, in addition to the usual rule that nobody can enter the King's citadel once it is exited, they also cannot re-enter the *attackers'* starting spaces. This makes it notably trickier for the King to get to the edge of the board. Moreover, it suggests that nobody can pass *through* any of those spaces, which makes movement *quite* a lot more constrained than in most interpretations. These changes somewhat balance each other, and seem to require a more thoughtful and strategic approach.
Very neat stuff. Anybody reading this from Pennsic (seriously, why are you reading LiveJournal at Pennsic?) might want to find a board and an opponent and try it out. I'll have to run a Low Company meeting sometime, so we can try these rules...