What a lovely idea! A worldbuilding club sounds like such a great way to spend creative, collaborative time. Yes, some, perhaps most, of the worldbuilding resources I’m aware of are either intended for adults or focus on some niche audience (the toolbox-type resources). I’m not aware of any platforms specifically geared towards children, but there are some solid all-ages options.
Microscope is probably my top choice for group worldbuilding projects in general, especially for older children. It’s intended primarily as a game and is a blast to play. But game designers and writers also use it to great effect for larger projects. The game relies on movable cards of some kind, but even before social distancing began, many people (myself included) replaced those cards with online tools like Trello. So it’s a good option at distance too.
That said, tools like Microscope rely on a high degree of cooperation, sustained attention, and spotlight-sharing, and that might pose a challenge for some younger groups (but also an opportunity to practice valuable social skills). For group worldbuilding with young kids, my main recommendation would be to look for (or come up with) tools that add a bit more structure to the worldbuilding. One approach that’s worked for me is to come up with a scenario beforehand with a defined scope. For example, you could draw up a map of a fictional place, say an island, and “leave blanks,” either literally or figuratively in the form of key unanswered questions or topics for the group to focus on. I find that a visual aid of some sort, like a map, can help ground a group (of kids or adults) in the shared reality their creating. Maps also create an easy way to divvy up work among members — I’ll describe what’s over this mountain, you describe what’s over that one.
If you’re more interested in organizing solo worldbuilding projects (i.e. the club would meet about members’ individual creations), then you might be interested in looking into the process-type resources linked in the article above. Those resources provide questions and hooks and draw attention to potentially overlooked areas of worlds being built. I remember participating in a couple of delightful worldbuilding and speculative-fiction writing summer camps when I was a young teen that worked much like that. Each day, we discussed a new aspect of our worlds as a group and shared ideas. The instructors guided that process and helped us set goals to move us through each step of the process. I could see something similar working for a range of ages.
As far as organizing and presenting the work comes out of the club members’ worldbuilding goes, as you mentioned World Anvil is an excellent option. Its map features are especially helpful, and though it’s not aimed at children in particular, the platform is flexible and easy-to-use enough that it can work for a range of purposes and ages.
Those are my top suggestions. I wish that I knew of more kid-focused worldbuilding offerings. If you find helpful ones, please send them my way! I’d love to learn about them. Good luck with the worldbuilding club!
