Let it be known, verily and forsooth, that Our Fair City and its environs is a kingdom replete with every variety of nerdery known to man, woman, halfling, and beast. Boston is the undisputed center of the nerdverse — a mothership for dweebs, techies, trekkers, weirdos, and gamers.

“Our mainstream is geeky,” said Kevin Harrington, who runs an annual comedy festival called Geek Week. Because most audiences in Boston understand obscure pop culture references like “natural 20” (a Dungeons & Dragons reference) or “these aren’t the droids you’re looking for” (from “Star Wars”), he can “inject geek” into his shows.

The number of area colleges and universities, the many centers for research and technology, and their annual influx of new blood doesn’t hurt.

“Boston geeks are today’s Boston Brahmins,” said Tim Loew, executive director of MassDiGI, a center that supports video game development in the Commonwealth. “We are a brains and innovation city and geeks rule the brains and innovation world.”

Plus, to declare one’s nerdy predilections is easier now than ever. “It seems like geekdom in general is on a growth trajectory, and that’s especially true around here,” said Nat Budin, who helps run Intercon, which calls itself the “premier multi-genre live action role playing (LARP) convention in the world.”

There is overlap. Enter the world of Harry Potter fandom and you’ll meet players of Dungeons & Dragons or Mass Effect, Portal, or World of Warcraft. Or people who design games. Or people who dress as their favorite avatars from their favorite games. A Mobius strip of nerd activity.

“The geek community in Boston is like a Venn diagram,” said Cathy Leamy, a comic book artist from Cambridge. “I see the same people everywhere I go. I love this city for that.”

And, you’ll find, these groups will welcome you with open arms. Herewith, whatever your brand of geekery — be it playing games (video, tabletop, role-playing), reading science fiction or fantasy, dressing up like your favorite character (a.k.a. cosplay), attending conventions, medieval reenacting, programming video games — our (incomplete) guide to the major genres and breeds, and how you, as a neophyte or old wizard, can best get your game on. Or get your tunic on.

Tabletop gaming

If you’re into D&D, Magic: The Gathering, Settlers of Catan, or Warhammer 40k, get thee down to your local game shop. Pandemonium Books and Games (www.pandemoniumbooks.com, in Central Square, Cambridge) hosts nightly game nights. You can also get your game on at Comicazi (www.comicazi.com, Davis Square, Somerville), which hosts gaming several nights a week. Join the Role-Playing Fellowship of Greater Boston, a Meet Up group (meetup.rpfgb.org), whose purpose “is simply a vehicle to help new gamers connect with folks already engaged in the hobby,” said Christian Loidl, leader of that group plus the Boston Dungeons & Dragons Meetup Group (www.meetup.com/Boston-DnD). “Anybody can join, as long as they are respectful to everybody and are genuinely interested in giving this great hobby a try.” Boston’s The Compleat Strategist (www.thecompleatstrategist.com) is another worthy game shop.

Live-action role-playing

If you’re hankering to don a costume and portray a character, LARPing is your game. Nero Boston (www.neroboston.com) runs its games in “The Duchy of Volta,” “a harsh and wild land filled with danger, magic, and intrigue.” If steampunk is your preferred genre, try Steam and Cinders (www.be-epic.com). Middle- and high-school kids can “larp” at the Arlington Enrichment Collaborative (www.arlingtonenrichment.org). “We hold each other to the idea of ‘doing awesome things,’ ” said Eric Love, director of the LARP Adventure Program (www.larpadventureprogram.com). They host an open house on Oct. 18. Intercon (www.interactiveliterature.org/M) is the annual LARP convention held in March.

Swordplay and medieval reenactment