I thought I knew a reasonable amount of D&D history, but after reading Jon Peterson's Playing At the World, I feel a sort of amused contempt for my past self, that poor ignorant yokel. I no more knew the ingredients of D&D than I did the secret recipe of Coca-Cola. You should read it so you can feel smug too.
Why should a book that's concerned largely with D&D prehistory be interesting to D&D players? My new favorite author Jon Peterson puts it well: "For all its long-windedness, Dungeons & Dragons is hugely underspecified: many of the core principles of its system are tacit ones, so familiar to the authors that they were blind to the need to record them. Only by a very close reading of the earliest rules, and by placing elements in their proper context in the tradition of wargaming systems, can we even conjecture about the intention behind these ambiguities and omissions. As usual, our familiarity with later versions of the game hinders us rather than helps us; we must forget what the game became in order to discover how and why it got there."
Here's how good this book is. Peterson's book is 720 pages, and while I was reading it, I was constantly wishing it was longer.
This book shed light on a lot of things that I've wondered about, sometimes on this blog.
In 2010, I wondered, "What is a midgard?" and wished I could get the rules for one. http://blogofholding.com/?p=265 Now I know a lot about the spread of midgard-style games, the play-by-mail milieu in which they existed, and the reasons that most of them petered out before they really began.
In 2012, I thought, "Look at all these dowels in the Chain Mail rules! That's cool!" Now I know that the use of dowels to mark altitude comes from the Fletcher Pratt naval game, where "airplane models are attached to a notched pole, where each notch measures a level of elevation at which craft may fly."
It's also shocking to see the term "Saving Throw" in Tony Bath's 1966 medieval combat rules (which inspired Chain Mail). "City militia may only attack heavy infantry if they can throw a 5 or 6. If attacked by them they must throw a 4, 5, 6 to stand, otherwise break and are diced for... If fighting takes place, one throw per 5 men, militia lose half total, no saving throw, cavalry lose one-quarter, saving throw of six."
There's lots more good stuff, including many details of Arneson's original game rules. For instance, Arneson said that "players were not intended to become harder to hit and take more damage as they progress. Instead they were to take the same amount of hits all the time (with the exceptions of spells, magic, etc.) while becoming more talented in inflicting hits and avoiding the same. This has a great equalizing influence." Imagine a version of D&D where HP stays the same while AC goes up as characters gain levels.
In short: Grab a copy. If you're a subway commuter reader, like me, get the kindle version: 720 is a lot of pages.