I have an old-school D&D campaign planned out. 1st-level, rural town. Like a reverse scooby-doo - small trivial problems like lost livestock resolve to hint at deeper mystical evil. As they level up they’ll find dark cults and demonic influences. The peaceful rustic countryside is far from what it seems.

But the players never get it together enough to set up a good date. The last campaign was fun, and they all said they wanted more. So I just keep writing more NPCs and extending the setting.