[dragonwriter]

> but how do you enforce plot progression in such a truly open world?

I'd imagine a mixture of general prompting/training the LLM on techniques like those used for plot progressiom by human game masters in TTRPGs and guidance via systems tracking progress and injecting contextual prompts based on mechanisms like those used for tracking and guiding plot progression in GM-less/GM-replacement systems (e.g., the Mythic Game Master Emulator) for TTRPGs.