My favorite sightseeing stops include caves and inactive mines. Cave tours inevitably include tales of the cave’s original explorers. I imagine myself in their place, delving by a feeble glow from a lantern, discovering underground landscapes and traces of people and creatures long gone, and I relish the feelings of wonder and mystery. My love of dungeons seems inevitable. In sprawling undergrounds, even modern lights don’t reach far before darkness engulfs their glow. I gaze into midnight shafts and feel a shiver much like leaning over a rail on the 95th floor. These tours always pause to extinguish all the lights and give a taste of complete darkness, but not before making sure no one feels close to panic. Like heights, spiders, and snakes, darkness triggers a primal fear that we share.

As played by most groups, the Dungeons & Dragons rules for light work like this: When the party starts their descent into darkness, the dungeon master asks what they have for light. Perhaps everyone has darkvision and that’s that. More likely, the group includes a human, so someone fires a torch or casts light and then no one pays attention to the subject until the next dungeon.

Through most of my experience as a DM, I played that way. The same goes for the multitude of DMs I’ve played with. After all, the rules as written make careful attention to light seem like a chore. How can anyone be expected to keep track of who carries a light and how that glow interacts with the senses and positions of various characters? You need a computer for that. My scrapheap of article-ideas-never-written includes a post describing light as a thing everyone ignores because it never adds fun. Everyone would have ignored that post too.

Surely tense dungeon-survival sessions can bring fun. In those campaigns, parties struggle to escape the dungeon with their loot before their supplies of torches and oil run out. But most D&D players favor heroism over such grit. Besides, D&D gives so many characters darkvision that calling out the stumbling humans and halflings seems pointless.

I’ve changed. When I run dungeons now, I pay some attention to light without getting mired in detail. The benefits of a little consideration surprised me.

As a party explores a dark space, I pay attention to just one thing: about how far they can see past their front row. For most groups, that’s 60-feet from the character with darkvision closest to the lead. And then when I describe, I mention what they can’t see because of the cover of darkness. When possible, I describe any sounds that come from that shrouded space. Imagine the scratches, the whispered malevolent voices, the creak of doors, the drip of water. Sometimes perceptive characters see glowing eyes that suddenly wink out in the depths. If the party recklessly chases ahead into the unseen, they deserve the panicked moment when monsters close from every direction. When I draw maps as players explore, my lines for the walls end where the darkness starts.

That small regard pays off with a sense of tension, atmosphere, and mystery.

In cramped dungeon rooms, light hardly matters, but in long corridors, underground cathedrals, vaulting caverns darkness easily swallows the feeble glow of a lantern. Darkvision only makes 60 feet seem like dim light. Beyond that who knows what spies the party’s glow and clamor?