When I landed with my husband in Sydney, I had little idea what to expect. We knew we were leaving London for a sunny country, a place of obscurely dangerous animals, strong beer and robust humour, and a city with a very famous landmark. But we didn’t yet know what the people would be like and how – or whether – we’d manage to make friends here.

But we had a secret weapon. We are the sort of convivial geeks who like to get together in a room, roll dice and pretend to be wizards. It’s how we met each other, and it’s how we met many of our friends in London. So off we went looking for a game of Dungeons and Dragons (D&D).

At its best, D&D is amateur dramatics crossed with fantasy fiction, created collaboratively among a group of friends. It’s a superb hobby for creative types who enjoy both systems and stories, who have the confidence and wit to respond quickly to unexpected things, who can give and take and negotiate time in the spotlight, who enjoy puzzles and the process of exploring a character, an environment or a scenario.

At its worst, it’s hours and hours of casting Magic Missile against goblins, rattling dice for every choice, and looking up complicated grapple rules because no one can ever remember what happens when you try to actually grab a monster. If the wizard can’t remember what spells they have, the rogue is playing Candy Crush on their phone and the games master can’t plot their way out of a wet paper bag, then chances are it’s not going to be a fun afternoon for anyone.

The core of tabletop games is always the other players. In the wake of D&D’s popularity, games have been designed to tell simple or complicated stories, with different emphases on setting, chance, improvisation or achievement. But every system is only as good or as bad as the people you play with. At its core, like every social hobby, it’s all about people.

So pretending to be a mildly psychic biker with a flamethrower for four hours in a custom game of Cyberpunk 2020 was, it turned out, the perfect way to make friends. As with sports and other social hobbies, playing together is a superb icebreaker, andan excellent way to introduce yourself to folks with whom you share at least one interest. It’s also a great way to feel welcome in a strange place; there’s something very comforting about shared jargon, shared cultural experiences, and those are hard to find 10,000 miles away from home.

Over time gaming becomes more than a bonding experience: it’s something that can be tailored, like a film night or a book club, to the shared desires of your group. You can explore darkness, horror and fear; you can explore the giddy heights of utter ridiculousness; you can do both, with the same people, at the same time. These days, it's a versatile hobby.

It wasn't always the case. D&D's co-creator Gary Gygax, with his insistence on the system’s inflexibility and his beliefs about the primacy of the game master, would barely recognise some of the games his work has spawned. His game has changed too; the hugely popular third edition has birthed a rival spinoff, Pathfinder, that remains more popular than its heavily redesigned fourth edition, which brought a more videogame-y feel to its class system and combat and in the process alienated players who loved the crunchy complexity and imbalance of earlier systems.

Now it’s striking out towards a fifth edition, D&D Next, which is going through a long testing process and receiving a decidedly mixed response from players. Alongside it is a blossoming game scene that is pushing in all directions. The internet has disrupted this world along with everything else, and one-page games and home-brew systems have joined mass-produced heavyweights to compete for gamers’ time. It’s hard now to envisage any one system regaining the supremacy that D&D once had.

But at 40 years old it’s still a cultural institution with fond memories for many people, and its legacy is not just measured in the games that cite it, explicitly or implicitly, as an ancestor. It’s in thousands of character sheets and campaigns, played out in homes, at schools, in pubs, in coffee shops. It’s in the friendships forged in made-up battles, the laughter and the stories and the fun. It’ll still be making me friends for many years to come.