I actually do an unit where I have my students create custom NPCs. First we take about a week exploring the world of humanities specifically looking at architecture and how the NPCs interact with the players. Then my students research a world religion, write about it (English) pick a sacred to that religion site to recreate in MinecraftEdu (math), and then finally create an ingame quest to teach other players about the religion. The NPCs are part of that last piece. We have lots of conversations about size and quality because those are the two variables that crash the server. They only create NPCs for a specific purpose, not just for fun. The more advanced students really get into the minutia of programming advanced quests, the beginners have very basic uses.
I have also had a class do a "book report" and recreate the important scenes from a book they were reading in English class, and they used NPCs as characters from the book to help narrate the action and explain the various scenes.
Sarai
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