Monster Design Tip: Take Away The Sun
Roleplaying Tips Newsletter #1110
Do you know how the eyeball works? It’s fascinating.
Think about a camera for a moment.
You point your camera at what you want to photograph.
The shutter opens and closes to control the amount of light.
A slow shutter action lets in more light. Great for dim conditions but poor for motion.
Fast shutter action limits light entering the lens. Great for when it’s too bright or there’s motion.
After the shutter, we have the camera lens, which brings all the light bouncing around into focus for a sharper image.
The focused light then hits the film.
And we get our photograph.
Eyes work the same way.

Your eye moves to what you want to see.
Light hits your cornea.
The cornea bends the light so it hits the iris.
The iris is your camera shutter. It gets big or small to let in more or less light.
Light goes through the iris to your crystalline lens.
The crystalline lens brings what you’re looking at into focus, shortening and lengthening light width to sharpen rays properly.
The focused light then hits your retina, which is like a camera’s film.
Your retina turns the image into light impulses that travel to the optic nerve.
Your optic nerve then transmits these impulses to the first visual relay in your brain, which project to your visual cortex.
Camera: Shutter => Lens => Film.
Eye: Iris => Crystalline Lens => Retina.
Very cool.
The Real Source of Vision
All this wouldn’t be possible without the sun.
We would not have eyeballs if our sun wasn’t beaming radiation at us.
This is our monster design tip today.
Most people think we see because we’ve got eyes.
But we see because the sun emits radiation, which hits Earth at the level of 1367 watts per square meter.
About 55% of that radiation is in the infrared band, which we can’t see.
About 5% is ultraviolet. Also can’t see. That leaves just 40% to visible light.

Our eyes evolved to process a certain bandwidth of radiation coming from the sun.
And from a game design point of view, if we change the sun, we change the game.
I See, I See…I Don’t See
99% of character races have eyeballs.
The PCs need the sun!
But our monsters don’t.
And this presents us with cunning encounter and adventure opportunities.
We take for granted that we communicate through sight.
I see you waving, running, smiling.
But our monsters need not be limited by mere sight.
So we design cunning environments that favour the monsters to increase the challenge.
For Example
Take kobolds. No, please, take them.
In many game systems these creatures can see in total darkness.
Standard dungeon fare.
PCs must light torches, cast light spells, or use luminescent bubblegum to spot foes up ahead avoid falling into pits.
But let’s see that as the Easy setting, pun intended.
For Medium difficulty, our kobolds target light sources.
In the first round, archers shoot lanterns dark, whip wielders snag torches out of white knuckled hands, and a dispel magic takes care of the bubble gum.
And within the blink of an eye, the party is at disadvantage.
For Hard setting, we drop magical darkness into the area.
Torchlight and bubblegum won’t work here.
And thus we bring monster design to bear.
We give our kobolds the ability to fight using sounds, like bats.
Or we grant them a blind fighting ability.
Or they get magical vision.
Whatever’s consistent and sensible for your world and campaign.
In this way, we create opportunity for player learning and adventure progression.
The Blue Kobolds see in the dark. Players learn to stock up light sources.
The Grey Kobolds see in the dark and have specialized troops who target light sources. Players learn how to deal with this challenge.
The Obsidian Kobolds use magic darkness and have a clicking language that lets them move, fight, and communicate easily. Players now must learn how to negotiate this challenge, pun +1!
Let’s Go Even Darker
Our player characters have eyeballs, and we realize we can design interesting challenges for them.
Take this idea further.
Some creatures sense vibrations in the ground. They don’t need eyes.
So you think about this and come up with fun encounters that put such foes at disadvantage.
Easy: Dirt ground, wooden floors. Any material that enhances the vibration sense. Add darkness.
Medium: Webs, ropes, boards…in the dark…over hazards.
Hard: Attack from below the ground.
This is the point of our tip.
Due to our real world assumptions, we have blind spots (ba dum bum).
Humans need open areas because we need to see.
We don’t even question this.
But monsters need not obey such constraints.
If a monster doesn’t have eyeballs, it doesn’t need light, open spaces, and clear atmosphere.
So we design monsters that can burrow through the ground and “see” just fine with their vibration sense.
They attack from below, catching PCs by surprise.
“The floor is lava bulettes!”
Tentacles of Design
So imagine now a creature with telepathy and darkvision. A mind flayer, for example.
They don’t need lit areas to help the characters. Like our kobolds, they operate just fine, even in their own magical darkness.
And they’ve got telepathy. They don’t even need to hear anything.
Easy: Magic Darkness. The party can’t see.
Medium: Magic Darkness with thundering noise. The PCs can’t see or hear anything.
Hard: Magic darkness with mimics of character voices. The PCs can’t see who’s talking and can’t trust anything said.
Our goal is to leverage our monsters’ senses and put them in environment they thrive in but give player characters ever-greater challenges.
Easy, Medium, and Hard extrapolations of monster environments where monsters have different senses.
This gives you theme, tactics, and cool encounter environments.
We have eyeballs because the sun exists. Take away the sun.