Light: Mechanics & Its Role in 5e

Last Updated on November 17, 2023

If you’re a human in real-life meatspace, which you probably are (I’ll admit, species dysmorphia can be a thing), chances are you need a certain amount of light for your eyes to work.  

Lighting matters in DnD, although it can be a difficult thing to manage.

If you are a new DM or you have a table of mostly new players, you might consider just waving your hand and saying, “Oh, there are torches in the walls/crystals that give off ambient light. Shut up and stop asking, Terry.”

Because lighting can be complicated and annoying to deal with.

The second thing to do is ask if anyone has darkvision, and then just say they can see normally. (Technically, they can’t, but again, following these rules can slow down play). Check out this post on darkvision.

In this scenario, if a player doesn’t have darkvision, just give them disadvantage on seeing or attacking anything past 20 feet.

But you? You’re a badass. That’s why you come to the Black Citadel. If you and your table want the added difficulty (and bonuses) that can come with utilizing light, then here is how you manage.

What Does Lighting Do?

Mechanically, lighting determines the accuracy of any PCs’ or NPCs’ abilities out to a certain distance. For flavor, lighting adds to the mood, tone, and roleplay value of any given scene.

Levels of Lighting

Bright Light

This is light that lets every character see normally. Even an overcast day provides bright light.

This does not affect the range of anything, and it does not provide advantage or disadvantage. No worries here.

Dim Light

In Dim Light, such as that found at dawn, dusk, and/or at the boundaries of what a fire or light source can produce, you have what is called Lightly Obscured.

Many DMs will say a full moon provides enough light to be Dim. This is true; however, if you are underneath a shadow, even during a full moon, it is still too dark to be called Dim.

Have you ever been away from city lights during a full moon? It’s brighter than you’d think. Especially if there is snow on the ground reflecting that light back up.

Have you ever been in the woods away from a city during a full moon? The leaves cast shadows, and it is still incredibly dark.

Don’t believe me? Talk to a Ranger.

Darkness

Darkness, such as nighttime, being underground, or being inside a room with no windows and doors, creates an area that is Heavily Obscured (see below).

Magical Darkness also creates this condition.

Using Light and Dark

Before we talk about creating lighting to your tactical advantage, let’s not be hasty.

We should always use the environment to our advantage.

If you have darkvision, consider reducing the amount of light in the room. If your opponents lack darkvision, then you suddenly have advantage on your attacks. (And all the rogues said, “yay!”)

The easiest ways to control light are with the cantrips thaumaturgy, prestidigitation, control flames, and druidcraft.

Furthermore, increasing light can be more than just a defensive maneuver. If your enemies have Light Sensitivity, you are at the advantage.

Homebrew Rule: Adjusting to Light

If you spark up a torch, cast a fire spell, or blow something up while in nonmagical Darkness, consider having everyone who isn’t ready for the increase in light to be taken by surprise and be blinded for 1 turn.

The opposite can also work. Yes, Darkvision and the like as written do not cover this situation, but most creatures still need a moment to let their eyes adjust if they don’t know it’s coming.

This turns lighting into a tactical reality instead of just a nuisance.

Setting the Mood

Let’s top this post off with a list of the best spells, equipment, and magic items that can create or block light.

Spells, Equipment and Magic Items

• Create Bonfire does not explicitly have rules for creating light; however it does last for your concentration. A normal fire fills a radius of 10 feet with bright light and additional 10 feet or dim light.
• Dancing Lights creates four floating lights that shed Dim Light in a 10-foot radius each.
• Light allows you to create a non-fire using a torch out of any object. It sheds Bright Light for a 20-foot radius and Dim light for another 20 feet.
• Produce Flame allows you to create an effective light source (10 feet bright/10 feet dim) that you can also throw at your enemies!
• Darkness will plunge everyone into Darkness that no light source can illuminate. This is a tactical decision that should be used intentionally. Not even Darkvision can pierce it, since light is a cantrip and this is a 2nd-level spell.
• Daylight will create Bright light for a 60-foot radius and Dim light for another 60-foot radius. This can also be placed on an object and carried with you. It is a 3rd-level spell and is therefore stronger than Darkness.
• Maddening Darkness is an amazing spell that can be turned into an environmental hazard. It blocks all light and darkvision and causes psychic damage.
• Torch is a basic piece of gear that comes in almost every starting pack. When lit, it sheds bright light in a 20-foot radius and dim light in another 20-foot radius. Make sure to use control flames to expand that, if possible. If you’re a DM, use control flames to halve it and challenge your players.       
• Flame Tongue is an enchantment that can be placed on almost any weapon (typically swords). When activated, your weapon will deal additional fire damage but will also shed bright light for 40 feet and dim light for another 40 feet.