A typical world building session (Source: It's Always Sunny in Philadelphia) 

One thing I've been spending a lot more time with over the summer has been working on world building, and realizing the fantastic potential for building engagement and ownership with the world. Furthermore, from the perspective of the Dungeon Master, it takes a lot of work off your plate by not only letting the players design the world for you, but giving you hints as to what sort of game they're interested in.

Over the last quarter of my D&D social skills group, I put the kids in charge of a castle. They all took jobs, although the key piece was giving them a structure for each day- each student would choose a task they would focus on (working on skill development, doing something specific with the castle or surrounding areas, or interacting with a NPC), then at the end of the day, they'd meet to discuss the latest news, brought by raven, and choose their course of action.

On the final few sessions, they cleared out a drake's nest that was threatening merchant guild's profits, so the merchant guild representative for the castle offered them a town deed. This let them actually design a town by adding various features that cost money from their treasury.

By the end of the session, the kids had actually built the starting town for next year's adventure, and I plan to start the new party there, in a newly founded tourist trap in the shadow of a looming keep. (The kids decided to spend a lion's share of the budget on a theme park.)

What's fascinating about this is it gave me a glimpse into what the kids wanted, content wise. I've given them occasional goofy sessions, including one where they entered a painfully generic Japanese dating sim/romance anime, and had to role play as the various characters (the best friend, the elderly principal, the rival from a different school, etc.), and established that the arch mage NPC that occasionally hung out with them was obsessed with it- and the kids became obsessed with it too, going so far as to open a theme park about it. So, I now have to figure out how a D&D theme park would work, but I'm excited.

But behind all that, I'm just really pleased at how the kids just dove into it. This gave them an opportunity to come to a consensus on what they wanted out of the world, and the idea of buying town features was a familiar enough concept that they just dove in, loving it. Highly recommend something like that for anyone running similar groups.

In my personal games, I've been doing something similar- I recently started a D&D group with my old high school buddies, and we've all taken on duties with building the world. Two of us came up with the history and culture of the world, one is building a map, one is figuring out the science and geology, etc- this has given us all a sense of ownership of this world, and as we're looking at doing the rotating DM model, it gives us enough material to feel like we all have something to work with.

Ultimately, the challenge of being a DM is finding the balance between player agency and DM storytelling- going too far in one direction and you have murder hobos destroying your world, go too far in the other direction and you're railroading. However, by giving players all kinds of opportunities to build agency, you create an amazing experience where you're working with a world that you all built, not just one that you came up with, and the results are usually for the better.

Would love to hear your stories about communal world building- hit me up on twitter at @rollforkindness any time!