Today, I've decided to create a monster without nailing it down to a particular level or Challenge Rating. Instead, I'll set out guidelines for running that monster at any level.
Let's create a magma monster, a humanoid creature of intelligent lava that can serve as a simple guard or random encounter.
Let's start with its basic abilities. It should radiate heat, it should be immune to fire damage, and it should be able to throw magma at enemies in addition to hitting things with flaming fists. Let's give it a special ability, too; perhaps it can swim rapidly through lava and/or damage weapons at high levels.
![Magma monster](Magma monster 4b.png)
Okay, so what is its Armor Class? Let's set that at 15, but feel free to increase that if your group can beat it nearly all the time.
How about Hit Points? We'll scale that with level: its Hit Points are equal to 10 times the party's average level. So, if your party is rocking along at 8th level, they'll face a magma monster with 80 HP. You can increase or decrease that as necessary for your creature.
How about attacks? I'll leave the attack bonus to the DM; I think most DMs can instinctively pick a bonus that will hit PCs frequently without hitting all the time...and it's not necessarily bad to pick a bonus that will hit all the time. Anywhere from +5 to +10 should be fine for most parties.
What about damage? Let's go old school and make the damage a collection of d6s, and we'll make the number of dice equal to the party's level divided in half. A 4th level party will face 2d6 damage; a 10th level party 5d6 damage. Again, feel free to shift this up and down depending on your party's Hit Point totals.
It'll have a standard Fist attack that deals bludgeoning and/or fire damage (split up the d6s between bludgeoning and fire, favoring bludgeoning damage if using an odd number of dice). We'll also give it a ranged Lob Magma attack, and the range can be whatever's reasonable for your party and the environment: maybe only 10 feet at first or second level; maybe 50 or even 100 feet at higher levels. For simplicity's sake, we'll keep the same attack bonus and damage dice for melee and ranged attacks.
Now let's move on to its special abilities. It'll be immune to fire damage, naturally, and it should have an aura that does fire damage to anyone near it. At its simplest, it deals 1d6 fire damage to any non-magma monster within 5 feet of it. You can increase the number of dice and range at higher levels, and you might omit this feature entirely at level 1 or 2.
To that point, let's think about some optional abilities you might only add at higher levels. How about a magma creature that can slither through lava like a fish through water? That's simple: we'll give it a regular speed of 25 feet but a speed on lava of 50 feet.
Finally, we'll create an old-school ability that's really nasty. Imagine a huge magma monster towering over the heroes, and imagine a hero fighting through the intense waves of heat to swing a metal sword at the magma that makes up the creature. That magma should warp any basic metal weapon that hits it; it's like throwing a weapon into a forge.
So, we'll say that any non-magical weapon that scores a hit suffers -1 to its attack rolls, and once it reaches -5, the weapon is destroyed. That's tough! But PCs can still take these creatures down with magical attacks, magical weapons, terrain effects, and other cleverness.
OK, let's create a stat block:
- Armor Class 15 base
- Hit Points 10 * average PC level
- Speed 25 ft.; on lava 50 ft.
Fiery Aura (optional) Any creature not made of magma that starts its turn within 5 feet of the magma monster takes 1d6 fire damage.
Your Weapon Is Melting! (optional) Any weapon that successfully hits the magma monster suffers a cumulative -1 to its attack bonus. If it is reduced by a total of -5, the weapon is rendered useless.
Flaming Fist. One target. Hit: Bludgeoning and fire damage using a number of d6s equal to half the average PC level.
Magma Toss. Range variable, one target. Hit: Bludgeoning and fire damage using a number of d6s equal to half the average PC level.
Artwork found online without attribution, and my reverse Google image search found no original artist.