In Asimov & Silverberg's Nightfall, a modern world with 6 suns and continual daylight has a total solar alignment every 300 years. Archaeologists find a dig site with burn marks at strata associated with these events, and struggle to survive the pandemonium that happens when night falls and civilization falls into chaos. They burn everything in sight to create daylight. The survivors of the new dawn struggle with PTSD and paranoia and all that good stuff. That would make a fun D&D game. Maybe a campaign set in 30 days of night, or somesuch.