Messing With Monster Design: Variable Features

I’ve been playing a lot of the Cypher System, lately. Specifically, I was running a Star Wars game using Cypher. It’s a surprisingly-versatile system that can cover basically any and all thematic bases when running a game. To be sure, it won’t replace D&D, Call of Cthulhu, or World of Darkness, but it’s most definitely flexible enough to play games using any of those settings.

My favorite part of the system is the simple versatility of the challenge/NPC/monster design system. Popping open the core rulebook itself to the “NPCs/Enemies” section might deceive you into thinking that creature design is very complex. Each monster, despite essentially being a simple bucket of target numbers, tends to take up a full page. Each ability is listed in detail, and there seems to be a conspicuous amount of design work built into each monster or NPC.

“Why is this odd?” you might ask. After all, systems like D&D have very highly-developed monster design systems. There are tables full of numbers that define challenge rating, special rules on how to manipulate those numbers, and entire subsystems designed to create legendary creatures. So why should the Cypher System be so different?

Well, the Cypher system kind of prides itself on its difference. Monsters in cypher are the simplest thing in the world to design. Boiled down to their most basic form, a monster in cypher is 2 numbers: its difficulty, and the target number derived from that difficulty. That target number is equal to 3x its number, and represents the target number that a PC has to roll in order to hit it or dodge its attacks, and also normally acts as the creature’s hit points.

A difficulty 3 monster has 9 HP, and requires a PC to roll a 9 to hit it or dodge its attacks.

That’s it.

What’s with all the complexity?

A lot of it comes down to special features, powers, and traits. Like D&D (or basically any other RPG on the market), monsters feature a number of special abilities that allow them to act in strange and interesting ways. Mages throw fireballs, wolves trip and swarm, basilisks petrify. And the standard way to write out these abilities is to list them, with descriptions, in the monster’s stat block.

Except, this is Cypher, and that amount of detail is completely unnecessary.

Let me give you an example. This is what I wrote down for a standard Jedi Temple Guard in my game.

Jedi Temple Guard: Difficulty 4; 15 HP; Lightsaber and Force Powers.

That’s it. That’s everything I wrote down. Here’s one of the Jedi Masters.

Master Kwon Jara: Difficulty 6, 18 HP; Martial Artist (2 attacks, 3 dmg each), Force Powers: strong telepathy (7), weak telekinesis (5).

Why is it that I’m able to get away with this sort of simplicity, but the book itself seems to need an entire page to write up a kaiju? (here’s an easy stat block for a kaiju, by the way: Kaiju: Difficulty 10; Invulnerable except to other kaiju or special circumstances; kills non-kaiju with single attack) Well, it really comes down to one thing: the audience. When Monte Cook wrote the cypher system, he wrote it with intent to sell. It’s a published product, and therefore it has to have explicitly-designed mechanics, even in a system that’s this simple. When I’m writing for my home game, however, I don’t need that.

Creating Variable Features

When I write “lightsaber and force powers” in my Jedi stat block, I know what that means. I didn’t note the lightsaber’s damage because the jedi’s already difficulty 4, and a normal lightsaber (a one-handed weapon) already deals 4 damage. If I gave a difficulty 1 child a lightsaber, then I’d note that it deals 4 damage, but with the jedi, it’s implied. I also know what “force powers” means. I don’t have to note that he has “force push, force pull, force run, force heal, force jump” or whatever, and describe each of those, because I can look at “force powers” and know what kinds of things he’ll use. And I know that the difficulty of any attacks or defenses he uses is going to be 4.

I call these “variable” features. If I design a fire mage in a cypher game, and simply note that it has “level 3 fire magic”, then I personally understand what that means. I know that “fire magic” probably means fireballs, fire bolts, flamethrowers, etc. But it also allows me to create new, interesting abilities and features on the fly. If I give him a weapon, then “fire magic” could allow him to enflame it. If he needs to escape to a higher point in the area or flee the encounter altogether, then “fire magic” could mean creating jets of flame that allow him to fly. It could mean creating fire whips, fire punches, living beings composed entirely of flame, and so on and so on. As long as I follow that rule of “level 3”, then it doesn’t really matter what kinds of things the mage does. It all fits.

And while I love the Cypher System, and will undoubtedly talk about it again in the future, I’m using it as more of a setup, here. If I were to just talk about assigning levels in Cypher, then I wouldn’t be doing much to further your understanding of game design.

Instead, I want to show you how to take this concept of variable features and apply it to Dungeons & Dragons, and really any system with a structured method of monster/NPC design.

First of all, though, I’d like to note that variable features are specifically intended to be used in a home-game scenario. These sorts of features are completely inappropriate for published material, and should not be used as such.

The reason for this is simply that different people have different interpretations of what a certain concept might mean. When you write “fire magic”, you might mean flamethrowers and fireballs, but someone else who reads “fire magic” could think of hard-fire constructs like swords or shields made of fire, or the aforementioned propulsion system. Vague interpretations are fine when you’re the only one interpreting them, but become a problem when the interpretation is left to unknown parties.

With that out of the way…

Variable Features in D&D

The great thing about variable features in D&D is that they’re really quite easy to design. All you need is the Dungeon Master’s Guide and a basic understanding of monster design. If you need that tutorial on monster design, then I encourage you to read this article. If, however, you already know how to build a CR-appropriate monster, then let’s turn to page 274 of our DMG and get started.

Specifically, let’s think about my proposed Fire Mage and his “Fire Magic” feature. In this case, let’s say that it’s both offensive and defensive, since I can think of many ways one could use fire magic.

Understanding the Table

More than anything else, we’re going to be using the MONSTER STATISTICS BY CHALLENGE RATING table on page 274 of the Dungeon Master’s Guide. So let’s get a basic understanding of it, shall we?

The first column is our creature’s CR, or challenge rating. A single creature of each CR would be considered an “appropriate” challenge for a party of 4-6 adventurers of an equivalent level. In this case, let’s say that the fire mage is CR 3.

The second column is Proficiency bonus. In all honesty, this is the least useful of the columns, as it really only tells us what our monster’s ability scores need to be in order to meet the appropriate attack bonus and Save DC (by subtracting proficiency bonus from the attack bonus/save DC). Otherwise, it’s really only used for the creature’s skill bonuses. In any case, our CR 3 fire mage has a +2 proficiency bonus.

The third column is Armor Class, and our first Defensive statistic. Do I really need to say much more than that? I’m not going to do anything fancy with our fire mage, so his armor class will be appropriate to his CR: 13.

The fourth column, and second defensive statistic, is Hit Points. Again, not doing anything fancy, so our mage’s hit points are 101.

The fifth column, and first offensive column, is Attack Bonus. The mage’s attack bonus will be +4.

The sixth column is damage/round. It must be noted that when it discusses damage per round, it’s talking about TOTAL POTENTIAL damage per round. This means that if our fire mage hits a single target with a fire bolt, it should deal about 21 damage. HOWEVER, we KNOW that the mage is also going to be throwing things like flamethrowers and fireballs out there, and those can potentially hit multiple targets. For practicality’s sake, we must assume that the fire mage would only use one of these area-attacks if it could catch a minimum of two creatures within the attack’s area. Therefore, in order to maintain the TOTAL damage per round of 21-26, as described on the table, we need to reduce the damage of the area attacks. Therefore, while SINGLE-TARGET attacks will deal 21 damage, multi-target or area-effect attacks will instead deal 11 damage.

And our final column on the table, and our final offensive statistic, is the creature’s Save DC. Since we know that the fire mage will be using area-effect attacks, then it will also require a save DC, in this case, it will be 13.

Determining Offense

The beauty of designing an offensive variable feature is that it all really comes down to numbers. It’s all about those last 3 columns: Attack Bonus, Damage/Round, and Save DC. This means that when designing the offensive capabilities of the mage’s “fire magic,” we just need to focus on these 3 statistics. And since I already determined the numbers we’ll be using, it’s actually pretty easy to design the feature.

Fire Magic. The fire mage wields fire-based magic, and can use it in a variety of ways. If the fire mage targets a single creature, it makes an attack roll with a +4 bonus against the target, dealing 21 fire damage on a hit. If it instead targets an area (15-foot cone, 30-foot line, or 5-foot radius burst), all creatures within the area must make a DC 13 Dexterity saving throw, taking 11 damage on a failed save, or half as much on a successful one. If the fire mage causes continuous damage, it deals 4 damage at the start of the affected creature’s turn, and can be negated by taking an action.

Okay, that’s actually pretty wordy. If I were to publish a creature with a variable feature (which will never happen, by the way), it would look like the above example. However, these are intended to be personal features that allow us as GMs the freedom to improv a creature’s tactics in combat, so something more like this is perfectly fine:

Fire Magic. +4 Atk Roll (21 fire dmg), single target; DC 13 Dex save (11 fire dmg), 15’ cone/30’ line/5’ burst. 4 fire dmg/round.

The trick to designing variable features in D&D is knowing that you must be vague about some aspects, yet specific about others. You’re essentially creating a narratively-driven ability, where you can use your own personal imagination to influence the way the creature or NPC uses its features. However, D&D is a game where specific numbers are necessary to maintain balance. Therefore, even when creating this interesting, variable feature, you must know the basics off of which you can build your narrative palace. How much damage does it deal? What’s the attack bonus? What’s the Save DC? For all the cool descriptions you provide, these still need to be at the core of your variable features.

In addition, you should also know what sorts of areas to use for your monster’s area-effect abilities. This bit is more art than science, but in general I’d use the scale of Low, Medium, High, and Epic CRs to determine what numbers you need. Low means CRs 0-5 and probably qualifies it for the numbers I used above (15-foot cone, 30-foot line, 5-foot radius burst), Medium means CRs 6-11, and doubles the numbers to 30-foot cone, 60-foot line, and 10-foot radius burst. High qualifies as CRs 12-17, and doubles all the numbers yet again. And Epic would be anything CR 18 and above, and doubles the numbers one more time. If you want to know why I chose these levels, then please read my article on Class Design, where I talk about the different tiers of character levels.

Determining Defense

This one’s a bit tricky. When you’re designing an offensive ability, you just have to remember the numbers. As long as your damage output doesn’t outpace the limits of the creature’s CR, you’re not going outside the “butter zone.” However, when it comes to defense, the numbers are already pre-set by the creature’s CR, and therefore changing them can mess with your creature’s overall CR.

This isn’t a huge deal when designing specific defensive features, because you get to program that into the CR of the monster. When creating a variable feature, however, you’re making the assumption that a lot of its special powers will be invented on the fly. This means that you have to stay within some pretty specific numbers or risk the creature becoming too powerful for the party.

Personally, I’d avoid defensive variable features if you can. Unless you really know your numbers, it’s not worth it. However, if you’re on a deadline or you’re improving a monster, then there are a few basic rules to follow:

  • Don’t let the feature grant multiple resistances or immunities. Stick to one, and make it thematically appropriate. Granting too many resistances or immunities can effectively double your monster’s HP, creating a fairly drastic scenario.
  • Don’t raise a monster’s AC by more than 1. The general rule is that by increasing a monster’s AC by 2 points above the recommended number, it increases the monster’s defensive CR by 1. The higher you go, the more you risk unbalancing your monsters.
  • Don’t boost a monster’s HP. While features that grant temporary hit points can seem really cool for something like a rage-monster or a barbarian, it’s really more trouble than it’s worth. There’s no easy calculation to determine what HP level equals what CR, so it’s easier to avoid hit points altogether. Instead, consider a resistance, as it has the same effect without actually boosting the monster’s hit points.
  • Reference Pages 280 and 281 of the DMG. A lot. Pages 280 and 281 of the DMG present a number of class features and tell you how they affect a creature’s CR. These are fantastic guidelines when deciding the limits of your variable features, and are extremely helpful at determining whether or not you’re going to unbalance your monster. For example, giving a swordmaster NPC the Parry feature (adding +3 to their AC as a reaction against a single attack) only increases their effective AC by one, so folding that into the swordmaster’s “Swordmastery” feature won’t influence its CR at all.
  • Recognize that this will never be perfect. The very nature of variable features means that you’ll never get them exactly right. They’re intended to be quick and dirty, in order to give you more free time when designing monsters, and more freedom when controlling them in combat. We want to keep things balanced in order to give our players a strong experience, but this level of improv gaming is bound to get a little out of hand at times. That’s okay, as long as we’re able to course-correct and keep the game flowing.

Determining Utility

This one’s really easy. Just don’t go overboard. Really, that’s it. Utility powers CAN influence a creature’s CR (flight, for example, effectively increases a creature of CR 10 or lower by 2), but it’s not a huge deal. Letting a mage teleport around a battlefield instead of moving is effectively the same thing. A frog monster’s ability to climb on walls doesn’t really affect its stats. And a fire mage using flame jets to “boost” around the battlefield as a bonus action doesn’t suddenly make it any more of a threat.

Obviously, giving a CR 2 kobold a 120’ fly speed is a bit too much, as is deciding that your assassin suddenly has unlimited and impenetrable invisibility. But as long as you keep these things within reason (say a 30’ fly speed, or a single round of invisibility), it’s not going to be game-breaking.

How Does Any of This Help?

As mentioned previously, variable features have two major uses. First, they allow you, as the GM, to design creatures more rapidly than you would otherwise. Instead of mapping out every spell an NPC can cast, or every special technique a swordmaster has under their belt, you can simply throw in a catch-all feature with a couple of appropriate numbers. Second, it allows you to flex your imagination while you’re actually running the game, which can help you to create more vibrant and varied encounters. It also allows you to do things as a GM that wouldn’t normally be allowed by the rules or the stat block. Really want a villain to survive an unfortunate defeat? Suddenly that “Necromantic Powers” variable feature you gave her allows her to eject her soul from her body and fly away unscathed to find a new host.

In short, variable features give you more control over the flow of your game, and allow you to make more narratively-driven decisions than you might otherwise be able to make. And I encourage every GM out there to give them a shot.

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5 thoughts on “Messing With Monster Design: Variable Features

Add yours

    1. 101 is correct. What you have to remember is that a single CR 3 creatures is intended to be faced by an entire party of level 3 adventurers. 101 hit points should last a couple turns at most.


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