Square of Darkness

It cannot be seen, cannot be felt,
Cannot be heard, cannot be smelt.
It lies behind stars and under hills,
And empty holes it fills.
It comes first and follows after,
Ends life, kills laughter.
— “Riddles in the Dark”, JRR Tolkien

The answer, as any fan of The Hobbit will tell you, is “Dark”. The little riddle does a terrific job summarizing just how scary the absence of light can be. Darkness is insidious; it creeps between, devours whatever it touches and is always there in the corner of your eye, waiting.

And most Dungeon Masters forget all about it when the adventurers venture underground.

The rules for handling Illumination (and the lack thereof) should be tattooed in glowing ink on the inside of every DM’s eyelids. It’s one of their most potent tools when it comes to setting the atmosphere of the setting. A healthy fear and respect of the dark is a primal instinct we all share; tap into that, and you’ll have the players eating out of your hand in no time.

First, a recap of the rules as they apply to Fourth Edition D&D.

Light comes in three forms:

1. Bright Light isn’t particularly bright or dazzling, but is rather what we’d call “normal” light with no penalties. Booooooring!
2. Dim Light includes candlelight, moonlight, glowing fungi and any other kind of minimal illumination where you can just barely make out outlines and movement. It’s what I’d call “normal” in a dungeon environment if I’m feeling generous. Race which have Low-light vision (such as Elves, Half-Elves, Tieflings, Dwarves and Eladrin) can see normally in dim light. I guess it should have been called Dim-light vision instead. Folks with normal vision (which includes Humans, Halflings, Dragonborn) are at a disadvantage as their enemies gain Concealment, meaning they’re at –2 to hit.
3. Darkness, AKA “You’re screwed”. On a moonless night or in a room without a light source, your heroes (yes, all of the standard races) are at –5 to hit as their foes have Total Concealment. Meanwhile, those monsters with Darkvision (such as Kobolds) can still see just fine, thanks.

Don’t underestimate these penalties! –5 is like your STR 16 hero with a Greataxe suddenly fighting like a STR 10 dude with a wooden plank. It’s the difference between an INT 20 Wizard hitting with an Acid Arrow, and an INT 10 Wizard…… not.

Or, to put it another way, it’s like cladding all of those Kobolds in Full Plate Armour to give them a +5 AC bonus. Scary, huh?

Except it’s not like cladding them in Full Plate Armour as what our Darkness lurking monsters gain is Total Concealment, and that’s a lot better than any amount of armour. When in Darkness, your monsters can use Stealth to hide, and remain hidden and move up to 2 squares without requiring another Stealth check, even in Dim Light. A hidden enemy is a deadly one. Just ask any Ninja.

In Darkness (or when hidden in Dim Light), your monsters have Combat Advantage against the hapless PCs (PHB p280) while the heroes don’t – even your Rogue has to be able to see their target to be able to hit them (PHB p279).

A small group of Kobolds in a nice Dark Dungeon would hear and see the clunky armour wearing heroes approaching a mile away, hit them once in the Surprise Round then move back before the PCs even knew what hit ‘em. Rinse and repeat.

Don’t forget that even in a relatively well-lit Dungeon where there’s Everburning Torches on the walls or a coat of phosphorescent fungi on the ceiling, there will still be pools of shadow, and any monster with more than INT 2 will use them effectively. And so, dear DM, should you.

What can your heroes do to Fight The Darkness?

The first thing is, obviously enough, Bring Light. A humble Torch illuminates a 25’ (5 square) radius while a Lantern doubles that (50’ radius, 10 squares) and lasts a lot longer. The Sunrod covers a massive 100’ (20 square) radius but each one only lasts half as long as a pint of oil in the Lantern. Even with Sunrods as part of the standard Adventurer’s Kit, I recommend every party including a Lantern, Oil and a few torches on their equipment list. A Lantern will burn for a full 8 hours, enough for a full Extended Rest, while a Sunrod is only half that. More importantly, Oil burns and can be thrown – perfect for those time when you’re up against flammable foes.

The downside is that all this illumination announces your presence. and only illuminates to a fixed radius. Beyond that, we’re back to total Darkness or Dim Light meaning monsters with ranged weapons (such as the Goblin Sharpshooter with a Hand Crossbow, Range 10/20) can shoot without fear of the heroes being able to return fire effectively. Only the truly foolish (or brave, which is another way of spelling foolish) monster will go toe-to-toe with the PCs in their circle of light.

With a Wizard on your team, things improve dramatically. The Light cantrip is one of the best under-used spells in 4e; it’s a Minor Action and can be cast on any object or unoccupied square within 25’ (5 squares) and illuminates a 20’ (4square) radius area. Lob that in the first round of combat where the monsters lurk (or you suspect they lurk) and the advantages of the Darkness is gone. If you need a little illumination further than 25’ away (to spot a hidden sniper pinning you down, for example) cast Light on the Ranger’s arrow and let him take a shot – doesn’t matter if it misses, it’s the illumination it provides that counts.

Finally, have a Race with Darkvision on your team. So far, that’s just the Drow or Duergar. I’m disappointed that the Kobold racial write-up lists them with Normal Vision when the monster entry gives them Darkvision (another Update needed?). An all Drow party could operate in total Darkness without penalty and totally kick ass!

What I like most about the 4e D&D illumination rules is this quote (PHB p281):

Squares of darkness are totally obscured.

Hope I’ve shed a little more light on them!