Lore and Legends of the Dezzyverse

Darkvision, Infravision, and Light in the Dungeon

I’ve been playing D&D since the 80s. And I gotta confess. I never really liked how Darkvision (or Infravision, or Ultravision… etc) worked, either rules as written, or as played. Rules as written (5th ed, 2024), Darkvision allows your character to see in darkness as if it were dim light, and in dim light as if it were bright light out to the defined range. Such vision is monochromatic. Infravision from 1st ed is much the same, except that with infravision, the character sees sources of heat. Which allowed for all sorts of “creative” interpretations by Dungeon Masters and Players alike.

The problem with the rules as written is, it’s just a flashlight from your vision that only your character can see. The rules imply that, except for being colorblind, the character’s vision is otherwise unimpaired. If a note, for example, is written on the wall with enough contrast, the character can read it without difficulty. Things lurking around in the dark are visible, and can be identified. They are rules designed to be simple to interpret, remember, and apply. Infravision is much the same, except instead of a flashlight, it’s IR Nightvision goggles.

Rules as played, Darkvision and Infravision make being in the dark an inconvenience rather than a mystery. The difference between “dim light” and “bright light” are applied only mechanically, and even then, most penalties can be mitigated with class abilities or feats. There’s even the spell, Darkvision that confers the ability to a willing subject for 8 hours. Because the effects of being in the dark are so trivial, it’s often forgotten about. Exploring a dungeon is about as disorienting as a poorly-lit hallway. Descriptions include details that would likely be concealed, and when the dark is mentioned, it’s an uncommon enough detail that it becomes a hint that the adventure designers are concealing something.

Let me tell you a story about a TPK

Years ago, I ran a D&D campaign, and in the very first adventure, half the characters were humans, while the other half had Infravision. The characters went to the dungeon location a few miles from town and climbed down to brave danger and gather treasure. I asked how everyone was going to see down in the dark, and the players of the characters with Infravision announced they could see in the dark. Then everyone checked their character sheets. No one had brought torches, lanterns, lamps, no light sources. No one chose to go all the way back to town to get some light sources. everyone just strung rope between one another and the characters who could see in the dark led the unsighted deeper into the underground maze.

The party ran into trouble after angering the troglodytes who lived in the caverns, and most of the party fell in combat. Except for two characters who fled when the battle was going poorly. Two human characters. And in the dark, with no light, they stumbled about until the troglodytes hunted them down. It was exciting, memorable, and some of those players tell the story about that TPK even after more than 25 years.

The Dark is a tool for the Dungeon Master

Part of tabletop roleplaying is the shared imagination at the table. Dungeon Masters can set the mood, pace the tension, bring the players into their characters’ experience. The dark forces the DM to describe the dungeon with senses other than sight. Sounds echo, unknown smells linger. the air can be suddenly cold, or warm, dry, or wet. Darkness closes in, and the characters’ world grows very small indeed.

The dark also encourages the characters to stick together. One of the few comforts in these situations is simply knowing where your friends and allies are. Characters who head off into the dark by themselves often find trouble quick, fast, and in a hurry. Coming to the rescue becomes a terrifying race. Or worse, the stray character is never found, just the odd, broken piece of equipment marking their desperate fight for survival.

The dark also grounds the environment in the players’ imagination. We expect it to be dark in deep caverns or abandoned mines. Reminding the players of the dark keeps them thinking like explorers instead of tourists. This way, when the characters enter a location even with dim light, the presence of light alone becomes a clue to the mysteries of the dungeon.

Bring a Torch

In current iterations of D&D there is a trend towards offering the “Standard Pack” of gear to begin their adventuring career. These packs often include critical, if often overlooked, items and among them are torches.

Torches last one hour and cast bright light out to 20 feet and dim light an additional 20 feet. They throw shadows, and illuminate differences in color. At the DM’s discretion, a lit torch may be reflected from further still.

I like to use torches (or candles, or lamp oil) as treasure at times. Since torches add 1 pound of encumbrance each, scrounging torches from the dungeon itself allows the group to extend their time underground. Light, even among populations that naturally possess darkvision, remains valuable. If for no other reason, no one really wants to fumble around in bad lighting, even if they can see through the darkness.

Darkvision House Rules

At my table, I define Darkvision as being able to perceive the magical energies that the world radiates. Perceiving these energies reveal them to be a constantly changing blend of all colors at once. In practical application, this still comes across as monochromatic, but I think it helps sell “the world is a magical place” theme.

This also means that the environment when seen through Darkvision casts different shadows than the environment when seen by a light source. Clever people make use of this feature to aid in concealment. For example, perhaps a secret or concealed passage is present that when seen in Darkvision is concealed, but when a light source shines on it, the cast shadows reveal it’s presence without the need for a Wisdom (Perception) roll (or vice-versa). Messages written in a color of the same shade as the surrounding area would be all but invisible to Darkvision, but stand out clearly under direct light.

Conclusion

Tabletop Roleplaying is an exercise in immersion. The deep places of the world should feel dangerous, frightening. Denizens of the underworld have every advantage, after all, this is their native environment. The civilizations that have grown far from the open skies of the surface, use the dark of the underworld to their advantage. Natural hazards, cave-ins, deadfalls, areas of poisoned air, All of these are enhanced when presented from behind the curtain of the dark. Explorers need to be cautious, if not careful or they will find themselves lost in the dark.