Homebrewing Monsters, When & Why I Do
Dungeons and Dragons 5th edition has an array of monsters. Including all the currently available material, the total amount of stat blocks numbers over 2,000! With all the options, some might think that the standard material provides everything you need. However, for some, that is far from the case. Sometimes you have a monster that almost fits, but needs a different tone. Sometimes you want to alter a monster slightly in order to change how it will interact in combat. Or sometimes you want to make something entirely new, an abomination from the darkest pits of your world, the likes of which have never been seen before!
Over my time as a DM, I have had these feelings numerous times. The itch to create something entirely your own can be enticing, and often when I started out it would be standard for me to create something all my own to throw at the party. However, I began to realize that it was a very consuming task. My creations would soak up my prep time, leaving me with less to adjust the rest of the encounter. So eventually I decided on a method to determine when I should be homebrewing, and how much.
When to Homebrew?
Home-brewing Monsters, no matter how small the change, take time and energy. Sometimes both are plentiful. You have the time set aside, the energy, and the drive. It is easy to justify dipping into that well. This is not always going to be the case, and even when you do have that time and energy, it could be spent elsewhere. Is it more important to create a Dire Spider, or to adjust the weapons on a goblin that will show up on a single road encounter, or would that time be spent better elsewhere in your campaign prep? While the idea can be exciting to add another entry into your homebrew collection in your journal, sometimes that energy spent is not worth the payoff in the game. This can be different for everyone, and I personally feel it takes time to determine.
So now that I have determined I want to homebrew, the next question is why? I start off by asking myself what kind of impact this is going to have on the game. If I am trying to keep a specific theme, the monsters at my disposal might not really fit what tone I am attempting to cultivate. A light re-skinning will help change the flavor of a monster to match the landscape I am painting around. The goblin becomes an alchemist’s experiment gone horribly wrong, scuttling through the shop with its kin while attacking the adventurers. Sometimes a monster almost fits what you need, but is lacking some special trait or ability. The City Watch Captain was a skilled general in his prime, known to empower his allies with his words. You see a stat block that feels almost right, but want to keep that leadership element. Or sometimes I want a boss monster that the party will remember. The lake holds a dark secret in its deep, icy waters. One that the party will have to vanquish in order to escape with their lives. With a homebrewed boss monster, I can make sure that the fight will be the right level of outstanding and challenging.
Once I have decided that I want to homebrew, and determined the reason for the homebrew, the final question is how much do I need to change? Sometimes you can re-flavor and be done. Other times you can swap a few features around, bolting on or removing abilities to make the monster fit what you need. But other times it will come down to needing to make something from scratch, or close.
Re-flavoring: Putting a Brown Bear into a Robot Suit
Not all homebrew involves changing a stat block. In fact, changing the description of a creature can completely alter how the table perceives it. The key thing to remember when doing this is that while you may see the stat block and know what the creature was originally, the party has not. It all comes down to how you, as the DM, describe the creature the party is fighting. You control the perception of the table with your narrative text.
You can take a Brown Bear, a CR 1 creature with multi attack, and describe it as hulking automation. The bite and claw attacks become its twin weapons, a rusted iron pickaxe and a wicked stone sword sword. The party will not know the difference as they focus on taking down the creature. As long as your descriptions (and any artwork or tokens you use) are distinctly different from a bear, the table will be none the wiser.
This can be especially useful when you are trying to cultivate a specific atmosphere. If you have your party in the ruins of a long dead and super advanced civilization, a brown bear might detract from the tone you are trying to maintain. It fits mechanically, but having a wandering bear deep in a long sealed crypt might raise some questions (similar to “Who is lighting all the torches in skyrim crypts?”). Ancient automation might be exactly what you would expect to find.
I try to do this kind of home-brewing. It’s a relatively low investment of energy and time for what can be a big payoff. Especially at lower levels, this lets you use a variety of enemies that you might not normally see in your game. Sometimes, however, that creature does not fit exactly what you desire. At that point, it becomes useful to look into modifying existing monsters.
Modifying Existing Monsters: The Ghouls of Tomorrow, Today
Sometimes you find a monster, but it seems to lack something. That warrior lacks a display of their fighting prowess. A sorcerer would have an ability gifted by the head of their order, or the dark entity they have forsaken themselves to in return for power. For me, I wanted a more interesting Ghoul.
Currently, my table is running through the Iconic Gothic Horror Curse of Strahd. Those not familiar with the game just need to know that its horror is heavy, and because of that I try to use a lot of undead. One of my favorite low CR undead to use is the Ghoul. It is fast, vicious, and can be extremely unnerving when used correctly. However, I felt like something was missing with the standard ghoul.
I have a particular image in my head for how ghouls function in this current campaign. In my mind they function almost like a land piranha, moving in large groups until they find prey. They attack and, upon causing the creature to bleed, fall into a ravenous frenzy. Throwing caution to the wind, they descend on the wounded creature, solely focused on downing their prey so they can attempt to sate their unending hunger. To me, the stat block just did not match that. So I added a special trait.
Chapter 9 of the DMG talks about modifying an existing monster. It goes over concepts like switching weapons, or adding a shield and how that can change certain elements about a creature's attack or defense. For my piranha ghoul, however, the section “Adding a Special Trait” is what I wanted to use. Specifically, I want the ability that Sahuagin has called “Blood Frenzy”. This trait gives advantage on attacks to creatures missing some HP. It represents a feeding frenzy brought on by the sight or smell of blood. This trait is exactly what I wanted. I went further in the chapter, and found this ability in the ”Monster Features” table.
Once I had added this on I needed to go through and recalculate the expected CR of the creature. The DMG, the “Creating a Monster” section provides the guidelines for calculating CR. Referring back to our table, “Blood Frenzy” states to “Increase the monster’s effective attack bonus by 4”. Using that, I find that the new ghoul has increased its CR. That will be important when balancing encounters, otherwise you may accidentally TPK the party with your newest creation. It should also be noted that online tools exist as well to do the CR calculation for you.
For me, most of my home-brewing falls into this category. 5e has a ton of stat blocks available, and these minor adjustments can really change how a creature functions in battle. Changing weapons and changing traits are quick, easy, and can alter your monster a decent amount. It should be also noted that for spell casters, It can be even easier to how they function in combat. All you have to do is check what other spells would be available to the spellcaster in question. Nature-worshiping cultists have access to the druid spells? Expand your resources to all the druid spells available. You can create specific loadouts based on how they act in combat. Summoners that bring companions to battle and then stay back, assisting when they can, or strikers that lash out with combat magic. The opportunities are endless.
Sometimes, however, simple modifications are not enough. You have a particular need, or you want a lasting impression. At that point, you can homebrew a monster entirely.
Homebrew From (Almost) Scratch: Leave a Lasting Impression
This type of homebrew takes the most time and energy. Honestly, it is not something that I do all that often. But when made, such a monster can leave a mark on a campaign. I find you can really amplify the importance of such a creation by limiting the amount that you use them. That being said, I have a certain way that I like to make my own monsters.
As the title hints, even making a monster “from scratch” will usually involve some existing monster that has some aspect which I like. I like to think of this like the Grow Your Own Crystal kits I used to get as a kid. In order to make something, you would need a starting point, a seed. I might want a massive corrupted tree for the party to fight and start with a simple Awakened Tree. Or I may want a Lake Monster that starts off as a Kraken. Wherever I start, I try to decide what I see in this creature that I like. Is there a particular element of it that stands out? An ability or feature that makes it interesting? Or is it the feel of the creature overall? Sometimes it is not just one creature either. I may have two or even more creatures. Each has some element I want to bring together for the ultimate creation.
Once I know what I want, I start to quickly remove or change what I do not want, breaking this creature down to its basic elements. Often for me I focus on the HP, AC, To Hit and expected damage output. For my Lake Kraken, I had a narrative for this creature. Krakens, in standard DnD Lore, are powerful denizens of the deep. Some even live in the Elemental Plane of Water. But this creature was not in an ocean. It was trapped in a lake, far from any source of water. So I asked myself, what would that do to a creature used to having such a space? To me, that meant that it would stunt the creature in both size and capabilities. The AC might drop along with the HP, and it might lack the offensive powers that others of its kind would have as well. So I dropped the power on it.
There is an easy way to weaken creatures that already exist in 5e, if you know where to look. In the Tales from the Yawning Portal module, there is a set of rules for creating Reduced Threat Monsters. To summarize, this monster has half the normal hit points, and has a -2 penalty on all rolls. And they are worth half the standard XP in combat. This template is a quick and easy way to take a powerful monster and lower its danger without much work. I have seen this used before to represent an elderly or sick monster that is not as capable as it once was. In the case of the Lake Kraken
Home-brewing an entire creature from scratch can be very tricky. You can use CR calculations to ballpark your encounters, but it is not a precise science for a variety of reasons. One of the biggest reasons in this case was that the action economy would be very much in the party’s favor. My table, 7 players at this point, we’re going to be against this single creature. This led me to use a piece of 3rd party material called (Not So) Legendary Actions by Igor Moreno.
This pdf guides you on how to add one of a few legendary templates to your monster. It adds legendary actions, reactions, and HP depending on how legendary you want your monster in question. With this guide, I could make sure that my Lake Monster could match the party hit for hit.
Besides that, it came down to balancing out the offensive and defensive sides of the Lake Monster’s CR values. Following some ideas behind CR, I tuned the Offensive CR down more than Defensive CR. The creature would still hit hard, but kept a hefty HP pool and a high AC. This would ensure that the fight would last awhile, and really push the players to use their resources. With that being said, I then fiddled and tested the monster a bit, running it through some fake combats to see how it would fare against the party. Just for flair I added an old 4e condition, bloodied. When the Lake Monster hit 25% HP, it would gain access to an additional attack option. I hoped it would make the end of combat a bit more exciting. After some final tweaking, I felt like this would be the ultimate monster.
I built my encounter and prepared for my session. That combat encounter was certainly memorable. My table at the time was a mix of experienced and newer players. I wowed the newer players at the size of the digital token they were facing. I even included separate tentacle tokens to emphasize how big it was. The experienced players saw the flickers of kraken that the creature had been based on, and understood the battle they had up against them. It was a situation of would-be heroes versus a veritable monster.
In the end, they vanquished it, but not without some serious damage. Looking back at my notes, I think the monster could probably have used a bit more tweaking. But for my purposes, it was a big and memorable monster to throw at them.
Final Thoughts
Monster Home brewing is a valuable skill to have, although it's easy to get pulled in by the allure of it. It would take energy away from other elements of campaign prep. However, I found that trying to keep my alterations light tended to keep things easier. When I had a monster that fit mechanically but not thematically, I would reskin, turning that bear into a hulking stone construct. Sometimes the mechanics would need a slight change, and I would aim to adjust an existing monster. Change up weapons, swap out prepared spells, or adding on a trait could drastically change how a creature interacts in combat. That allowed me to leave the real homebrew for special occasions, when I wanted to make a lasting impression of an encounter.
I did slightly touch on my thoughts on CR, or Challenge Rating, as well as noting that it is more of an estimate than a definite calculation. In the future, I will elaborate on those thoughts, but that could probably take a post.
I will include links to a few of the homebrew creatures I have made below. These are very much still set up for DMing and would not be what I would consider “ready to be published” but I think they are good examples of what can be done.
Lake Kraken
So that is my thoughts and theories on Homebrew, when to do it and how to do it. How do you homebrew? What has been most successful in your homebrew? I would love to hear below.