Two blocks south of the city center of Aachen, near the cathedral that encases Charlemagne’s famous chapel, you’ll find a gaming store with a window full of tiny knights and monsters. Its existence in this medieval city of emperors is an amusing reminder of the complex relationship between the actual past and the fantasy version of the Middle Ages we’ve never been able to shake. That relationship is always worth pondering, but it’s especially poignant today in light of the news about the fellow who was arguably one of the most influential medievalists of the latter half of the 20th century: “Dungeons & Dragons” co-creator E. Gary Gygax, who died yesterday in Wisconsin at the age of 69.

Four years ago, when hardcore gamers celebrated “Worldwide Dungeons & Dragons Game Day” amid the shuffling of graph paper and the plaintive plinking of dice against Coke cans, the event was mostly a nostalgia trip, not a notable phenomenon in its own right. That wasn’t because the culture had abandoned D&D, but because old-school paper-and-dice gaming had evolved as the larger culture embraced RPGs, developed them for new media, and midwifed their mass appeal. Online gaming? Tolkien and Beowulf movies? Girls who are unafraid to enter comic shops? All of these wonders, at one time unimaginable, can be traced back to “Dungeons and Dragons”—specifically, to the bearded sage of Lake Geneva and the arcana he co-bequeathed to the skinny-armed boys who raised fistfuls of dice in geeky solidarity during the early 1980s.

Contrast those humble nerdlings of yore with the polished, professional women who flip through Harry Potter novels during their subway commutes. These valkyries are the goddaughters of Gary Gygax and the unknowing heirs to the mainstreaming of fantasy. So are their kids, from the girls who swooned over Orlando “Legolas” Bloom—girls who, a generation ago, wouldn’t have been caught dead watching a fantasy movie—to the boys who have slain every goblin the XBox can throw at them.

It was not always thus. When I was in middle school in the dark days of 1983, a science teacher rescued me from study hall with a weekly session of RPGs and military wargaming. That class, for which several of us received academic credit, solved the mystery surrounding the sprawling scale models of the European countryside that took up half of the chemistry room and the elaborate maps of imaginary places stapled to the classroom walls. The teacher, a retired two-star general, was always an iconoclast. Years later, when faculty were forbidden to smoke on school grounds, he reportedly researched the property limits and spent his lunch hours loping just outside the borders, puffing away in furious protest. Those were the sorts of adults who embraced fantasy back then: outsiders, autodidacts, guys who literally brought their vast knowledge of military history to the table, and similar pre-Internet obsessives who made their classmates and co-workers—the type whom every eight-year-old in the Western Hemisphere now knows to call “Muggles”—very, very nervous.

Of course, for those of us who were raised outside of an academic milieu, D&D also offered a valuable experience that later served us well: the game offered a preview of the systems, organization, and culture of a worldwide scholarly community. Hardcover tomes served as authoritative published sources. Pages of rules, charts, graphs, classifications of moral and ethical philosophies, and endless systems of nomenclature were all punctuated with academic abbreviations (“cf.,” “q.v.,” and so on) that required training and memorization. Like knowing how to use the Patrologia Graeca and its accompanying scholarly apparatus, mastering the material in the various D&D manuals was a skill not easily acquired. All of this stuff was, like the foundational scholarship of any field, composed by sages whom we knew primarily through their written pronouncements. They published regular supplements, such as Dragon magazine, which featured articles as specialized and as arcane as anything in Byzantinische Forschungen. From disquisitions on the ecologies of imaginary creatures to lengthy debates about the physics of falling and its effect on the proper way to calculate hit-point damage taken by characters wearing variously configured armor, Dragon was a newsletter, marketplace, and academic journal all rolled into one. Its luminaries even hosted annual and regional meetings; in-the-know players became attuned to rumors of contentious professional politics among the inner circle.

As an adult, I’m too self-conscious and jaded to return to the world of old-school gaming. That initial interest didn’t die; it simply matured, thank goodness, and now I seek a similar buzz in hiking, traveling, teaching, and writing. I’ve never worn armor, I don’t attend Renaissance festivals, and I can’t tell one scion of the house of Gondor from another. I will admit, though, that while working on Becoming Charlemagne, I drafted sprawling, D&D-like maps of Aachen, Baghdad, Constantinople, and Rome, simply to give myself a mental picture of each setting. I loved it. So help me, I felt like I was ten again.

At this moment, countless kids are watching their Lord of the Rings DVDs, reading Harry Potter, or playing fantasy games on their computers; perhaps their parents are logging onto Web sites under handles and encountering no stigma as they play at being someone else. Twenty years ago, most of them wouldn’t have touched a set of polyhedron dice with a ten-foot pole; today, they all know what a hobbit is, and they find nothing odd about wizards and magic and the trappings of popular medievalism, recast as they have been into forms that have decreased in intelligence but certainly gained in charisma. So here’s to Gary Gygax, an unlikely popularizer whose almost wholly derivative work broadened the appeal of medievalism by energizing the geek culture that now reigns supreme. I wish him a tomb protected by ingenious traps, and an adventurous afterlife where all of the hallways are perfectly ten feet square.