Understanding Monster Stat Blocks in 5th Edition
There is an ongoing war in my heart and head on whether I find making magic items or making new creatures the most fun. I’d like to think they’re on equal ground, since I like them for different reasons. Magic items are amazing to see in action, and have so much potential as plot hooks and can result in some amazing moments for the players. There’s a bit more self-indulgence in my love of homebrewing creatures. I can create something exactly how it is in my head, inciting delight over the cute little creature I made, or abject horror for the boss they’re about to fight.
Before we get to any of that, though, it’s good to understand how creature stat blocks are laid out. Knowing the rules and being able to work off examples is the number one way to get a semblance of balance from the beginning. However, creatures tend to have a lot more going on than magic items, save for the absolute most elaborate ones. This guide could not possibly be exhaustive, as there’s many things about making creatures you’ll only ever get better at with practice. For this review, we’ll use two stat blocks as examples: an Adult Red Dragon, and a Drow Mage. We’ll move from top left to bottom right.
Starting with the general information on the creature, get down the creature’s name, alignment, monster type, and size. The name, of course, can be whatever you want it to be in this case. We have some names in our examples, but if you ever have trouble coming up with a name for your creature, you can always come back to it. I know I tend to have an easier time naming creatures after I’ve made everything else!
Creature Type
Creature type and size are very important to distinguish, both being categories that can determine if a creature is affected by certain things in the game. There are fourteen creature types: aberrations, beasts, celestials, constructs, dragons, undead, elementals, fiends, fey, giants, humanoids, monstrosities, oozes, and plants. Plenty of these types are very self explanatory, but here’s a little breakdown anyway:
Aberrations. Alien-like creatures that have a sci-fi, eldritch look to them. They generally have multiple eyes and limbs, mind-altering powers, and can be disturbing to witness. Some aberrations, though, are simply otherworldly - like a creature you may encounter on another planet. Mindflayers, beholders, intellect devourers, and Quori are all aberrations.
Beasts. These are, for lack of a better term, normal animals. Usually the strangest thing about them is they may be larger than what you would see in our world. Otherwise, they are things like bears, deer, owls, dogs, cats, snakes, etc. You’d be hard pressed to find any beyond CR 8.
Celestials. These are any creatures that are holy in nature and / or hail from the Seven Heavens (or any equivalent in your world.) Unless corrupted, all Celestials are good creatures alignment wise, with angels and unicorns being the most common examples.
Constructs. These are monsters that are built or otherwise are objects granted life by magic or other means. Robots, some golems, and other automatons all fit this category.
Dragons. Self explanatory. Though, this category can also include creatures close enough to dragons to fit, such as wyverns.
Undead. This category includes any creature who is, well, undead. Some aren’t immediately recognizable as undead, such as vampires, but others are very clearly animated corpses, like zombies, mummies, or skeletons. Ghosts and specters also fit this category.
Elementals. These are primordial beings that represent a primary element - usually earth, water, fire, or air. They rarely represent more than one element, and tend to have appearances that invoke it. There are basic elementals for each of the elements, as well as things like genies and weirds.
Fiends. These are creatures of a dark origin, often manifesting in the lower, outer planes and embodiments of evil. Fiends are unique in the official rules by having a few subcategories to differentiate them. You don’t have to implement these subcategories - most effects from spells and magic items work on all fiends - however, if you want to keep the distinctions between them they can certainly be helpful.
Demons are chaotic, destructive creatures who live to destroy and consume. They are usually much more difficult to converse with and will stop at nothing to leave a trail of destitution in their wake. They’re at constant war with Devils.
Devils are much more lawful in nature, and while they, too, can be deeply corrupting and antagonistic forces, they tend to take on much more strategic and sinister means of getting what they want. Some Devils will even do perceivably good things in order to reach a farther, selfish goal. They are constantly at war with Demons.
Yugoloths are often neutral evil fiends who meddle in the affairs of their own kind as well as mortals. They’re tricksters who aren’t as refined as Devils but not nearly as chaotic as demons.
Fey. Hailing from the Feywild, these are chaotic if neutral creatures who often depict an overwhelming amount of positive energy - for better or for worse. They’re tricksters first and foremost, and often spirit away mortals into their games without really registering right from wrong. These include fairies, satyrs, centaurs, and pixies - but also hags and darker products of the wilds.
Giants. Another self-explanatory category, Giants are any creature that is almost humanoid like but is exceptionally large. Depending on the world you run, you may or may not have giants in your game, but they often have elemental leanings, like ice giants, storm giants, and fire giants.
Humanoids. Any mortal creature that hails from the Material Plane is considered a humanoid, generally. It’s likely most of the party is made up of Humanoids, which include nearly all player races unless they indicate otherwise.
Monstrosities. Can best be described as mutated beasts. They often are two beasts spliced together, or a singular beast with multiple heads. Displacer beasts, hydras, and owlbears are all monstrosities.
Oozes. A special category specifically for creatures who are sentient slime, essentially. Gelatinous cubes fall most famously in this category.
Plants. Got some treants and awakened shrubbery? They’ll go in this category. While you have creatures that are plant-like, this classification is specifically for literal plants.
Size
For sizing, remember that the literal, physical size of the creature doesn’t necessarily have to perfectly reflect the category. The sizes (tiny, small, medium, large, giant, and gargantuan) represent how many squares on a grid the creature controls. A giant constrictor snake controls four squares, for example, as it’s a large creature. However, that isn’t to say the snake is literally taking up a 10x10 cube. Same logic applies to a medium creature controlling a 5ft square. Think not just the physical size of the creature, but how much area they can cover.
Armor Class
The armor class for non-player creatures is determined the same as PCs. Meaning, it would be 10 + your Dexterity modifier unarmored. When armored, it’s the base of the armor type + your Dexterity modifier (though no more than +2). If you’re creating a creature who wears armor, you can determine with this method. Our Drow Mage has an AC of 12 when they’re not using the spell Mage Armor. If they were wearing armor, the parenthesis would indicate what kind, like padded, plate, or studded etc. However, if the creature is a monster who doesn’t wear armor, you instead will see something like the Adult Red Dragon that reads ‘natural armor’. Natural armor accounts for things like scales, carapaces, furs, etc. Natural armor can be whatever you wish and as high as you deem appropriate.
Hit Points
Hit points, like for PCs, are determined the same way as PCs, though the number of hit dice is generally a lot higher. You’ll see that both stat blocks have a number, then in parenthesis the number of hit dice + their Constitution modifier x their CR (roughly). The first number is their average hit points, determined by the dice and modifier. If the creature does not have a modifier for Constitution, then they’ll only have their hit dice. As you can probably tell by the Drow Mage, the number of hit dice is usually pretty random. You want to ballpark it to how much of a challenge you want the creature to be. Hit points are one of the easiest things to adjust on the fly, but you definitely want a good idea of where the total should be.
Speed
Speed on a stat block normally has their walking speed first, then any other speeds (fly, climb, burrow, and swim) follow it. Make sure to indicate which is which, and while each speed is different, they can’t take advantage fully of both in the same turn. If you have 60 ft. flying speed, but spent the first part of your movement walking 30 ft., you’d only have 30 ft of flying remaining, for example.
Stats, Saving Throws, and Skills
I likely don’t have to explain the stats, other than the fact that they don’t necessarily have to follow the same rules as PCs. Non-player creatures can have stats above 20 with ease, especially much more challenging ones. Saving throws are indicating their saving throw proficiencies, of which you can give as many that are appropriate. Speaking of - while it’s lower down the block, I’ll mention it now: the proficiency bonus of a creature follows the same progression as PCs in relation to CR. Generally, the highest it can possibly be is a +9 at a CR 30. Skill proficiencies also follow the same rules. Your average bandit would likely only have a +2 or so, but your big ole dragon has a +6, etc. Non-humanoid monsters are unlikely to have skill proficiencies unless they’re fairly intelligent, so consider this when hashing them out.
Damage Resistances, Immunities, and Vulnerabilities
These are pretty self-explanatory, but we’ll take a moment to talk about when resistances and immunities are good to add. A creature resistant to a damage type takes half damage when exposed to it, as opposed to immunity which makes it take no damage. Immunities are fairly rare save for instances where the creature is basically a manifestation of that damage type. It makes a lot of sense that an Adult Red Dragon is completely immune to fire, for example. The Drow Mage has no resistances or immunities, but it’s not uncommon for Drow to have a resistance to Poison, as it’s a damage type often utilized by the Drow on their weapons.
You’ll often see Bludgeoning, Piercing, and Slashing damage grouped together, as it’s very rare when a resistance to weapon attacks dealing one of those types is independent of the other two. Stronger, magical creatures are often resistant to ‘nonmagical’ Bludgeoning, Piercing, and Slashing, meaning mundane weapons don’t work as well on them. It’s worth noting that, even if it doesn’t explicitly say in the description, any weapon that has any sort of enchantment on it (such as a +1 longsword) is considered magical for the purposes of overcoming this resistance. Sometimes this resistance can be overcome by silvering a mundane weapon, in which case it would read ‘nonmagical attacks that aren’t silvered’, like for werewolves or vampires.
Vulnerabilities are also pretty rare and generally only exist in low level creatures. A Shadow is vulnerable to radiant, for example, and a lot of plants are vulnerable to fire. This means they take double damage when exposed to that damage type. Vulnerabilities can make fights very short if you do. But, if that’s alright with you, then have at it.
Senses, Languages, and Challenge Rating
A creature’s senses are any special sights/feelings they have as well as their passive perception bonus. This includes darkvision, tremorsense (feeling vibrations in the ground), truesight (seeing through illusions and invisibility), and blindsight (senses creatures around you even when blinded.) Darkvision and truesight generally have a cone-like distance between 60 and 120 ft. For tremorsense and blindsight, it’s treated more like an aura centered on the creature. Passive perception is calculated the same way as it is for players (10 + creature’s wisdom modifier + creature’s proficiency bonus.)
Languages are pretty easy to implement for humanoid creatures. Just use your best judgment. Determine if the creature has the intelligence to know languages at all - you generally need an intelligence score of at least 5 to be capable of knowing a language, for example.
I talk a lot about challenge rating (CR) in my article on combat balance, so I won’t get too into it here. Basically, CR is the rough estimate of how difficult a party of 4 average players of the same level would have against the creature. This is a pretty arbitrary number, and shouldn’t be taken at face value. Too many factors are left out when determining CR. For example, like the amount of magic items the party has, or their composition of classes. Do your best to give a grade to your homebrew creatures, but this number, again, really isn’t a good reflection on the challenge.
Special Traits
Now we’re getting into the fun stuff, and where some confusion can lie. Non-player creatures often have special abilities that follow the same vein as racial traits for PCs. However, there are a lot of creature traits that would never be available to PCs, or only become available through the use of a spell or magic item. Sometimes the traits are a detriment to the creature, such as our Drow Mage here, who has Sunlight Sensitivity, making them weaker in sunlight. On the flipside, a very common trait for powerful creatures is Legendary Resistance, which allows them to simply succeed a save if they fail one a number of times a day. It’s surprisingly difficult to find a full list of creature traits, hence why I talk about how helpful it is to check out other stat blocks before homebrewing your own, since what you’re thinking of may already exist.
That being said, Special Traits are my favorite parts of stat blocks, because you can basically give them anything you want. When you create a trait, be sure to stick to a similar wording you would for a magic item’s property or a racial trait. These traits are always inherent to the creature, but use your best judgment for whether or not the trait should have some kind of limit, or charges, etc. Legendary Resistance, for example, is a powerful trait, but can only be used 3 times a day, so it balances out more. A creature with a Spider Walk ability where they can walk on walls and ceilings is okay to keep passive, since it’s only helpful in certain scenarios.
This is a good place to put any unique passives that you feel your creature would have. Actions, bonus actions, and reactions are a separate section, so we can save those for later.
Spellcasting
Casting spells is considered a special trait for a creature, so even though they involve using actions, bonus actions etc, the list of spells is kept in this section. There are two versions of spellcasting for creatures: learned spellcasting, and innate spellcasting.
Innate Spellcasting means the creature can cast the spells without material components, and they are known to the creature regardless if they’re a mage or not. Innate spellcasting does not use spell slots, but instead allows the creature to cast that particular spell a number of times a day. This list of spells is usually divided into three sections: At Will, 3/day, and 1/day. The 3/day and 1/day can sometimes be followed by each, which means each spell following can be cast once per day. For example, our Drow Mage can cast dancing lights, fairie fire, and levitate (self only) once each before finishing a long rest. Sometimes, a creature with innate casting can cast leveled spells ‘at will’ as if they were cantrips, but those spells are rarely, if ever, higher than level 2.
Learned Spellcasting means the spells in the list follow the same rules as PC casters, in that they use spell slots, material components, and arcane focuses. This usually reads as just Spellcasting, and will generally say what level caster the creature is and from what spell list they pull their spells, as well as what their Spellcasting modifier is. Sometimes the modifier used for this casting is different from their innate casting if they have both traits. You determine spell saves and to-hit bonuses the same way for both traits, and you can follow the general class features of the list they pull from for how many slots they have at each level. You don’t necessarily have to follow this rule - I’ve mixed spell lists before for this trait, but keep the spell slot progression the same as a Wizard by default.
More recent Wizards of the Coast content has done away with a lot of learned spellcasting for the sake of simplicity. However, if you’re the type to use the PC stat building rules for humanoid casters, this info is still worth keeping in mind.
A creature’s CR doesn’t have to match the level of spellcasting they are capable of. Sometimes a creature’s spellcasting level is different from their overall challenge. This is something that you can make your best judgment on, but as a rule of thumb: mages have powerful magic in exchange for low AC and health, generally. In the cases of innate spellcasting, remember those spells generally have a lot less variety. Innate casting shouldn’t have a huge list at their disposal, given it’s inherently more powerful than learned casting.
Actions
Abilities under this section are assumed to require an action to perform, unless it specifically says otherwise. Most of the time, these actions are attacks, with an individual paragraph for each weapon / method of attack the creature has. If the creature can attack multiple times, they’ll always have the Multiattack feature, which will specify how many of each method of attack they can take. For example, the Drow Mage does not have Multiattack, so it can be assumed each item under this section requires one action. Our Red Dragon, on the other hand, has Multiattack, which states they can use their Frightful Presence, then make three attacks - two with its claws and one with its bite. If it wants to use its tail, that would be the only attack it could make. This accounts for the Fire Breath as well.
Some abilities are particularly powerful and thus have a recharge. The Fire Breath is a good example of this, but let’s break down some options you have:
Recharge 5-6 means you roll a d6 at the start of each of the creature’s turns after using the ability for the first time in combat. If you roll a 5 or a 6, they regain the ability, if you roll a 1-4, you have to wait to try again next turn. Sometimes this only allows for a recharge on a 6, or on a 4-6, but a 2 in 6 chance is the most common. Dragon breaths have this the most commonly.
#/day means the creature can use this ability a number of times every 24 hours. This is not the same as a long rest. They have to wait a full day from the time of using it to get it back. This is seen in innate spellcasting, as well as summoning abilities like with the Drow Mage.
#/long rest means the creature can use the ability a number of times per long rest, naturally. This is pretty much only seen in humanoids, and more often, it’s just mimicking a class ability that does the same thing.
You may give an ability a unique recharge, like the creature not moving for a round, or consuming blood, or staying out of direct sunlight. These can also be added to passives to give a limitation to an ability. Adding these limitations makes it easier to buff or nerf testy abilities that can push a creature to become too difficult or too easy.
Reactions
The stat blocks I’ve been using as examples don’t have this section, but reactions are kept under a separate section. Unless the creature has an ability otherwise, they only get one reaction a round. Usually it’s some kind of defensive ability like a Parry or potential damage dealt to someone who’s attacked them, like Hellish Rebuke.
Legendary Actions
This section isn’t one you have to fill out unless the creature is, well, legendary. This doesn’t mean there has to be only one creature like it in the universe, but it does mean that type of creature is renowned for their power. Legendary Actions are unique in that each one is used at the beginning of another creature’s turn in the initiative, though only one can be used at a time. This allows your big boss to move more than once a round, but with a limited number of things they can accomplish. Legendary Actions have charges that restore at the beginning of each of the creature’s turns. Most legendary creatures have three of these charges, but the most ruthless can have up to five.
Legendary Actions follow similar formulas across creatures: 1-2 actions that require only one charge, 1 that requires 2 charges, and sometimes one that requires 3. These actions usually consist of one attack, one movement ability, and one ‘special’ ability. Our Adult Red Dragon, for example, can make one tail attack, move, or do a special wing attack. The special ability always requires multiple charges, and usually requires a saving throw. You can get really creative with these, but remember, they should be fairly limited. Stick the general sequence of attack-movement-special and you’ll have an easier time balancing them out.
Lair Actions
Moving off of Legendary status, these creatures can also have lairs, which are areas of which they have a measure of control over. If you read stat blocks mainly from the internet, these, along with Regional Effects, are very easy to miss, since they usually aren’t part of the main block. Dragons are a classic example, but Beholders, powerful spellcasters, Sphinxes, and many other creatures also have lairs. It can be anything from an ornate ballroom to an icy cave to a labyrinth, but the area that is truly considered the creature’s ‘lair’ is usually the final place the party encounters them in. As such, Lair Actions are thematic to that area, and are activated at Initiative Count 20. This means you treat the lair action as if it rolled a 20 on initiative, so there’s a chance some creatures in the initiative count will take their turn before the Lair Action activates. Lair actions always lose if there’s a tie in the initiative count.
Only one Lair Action activates a round, and creatures usually have three options to choose from. If the Lair Action imposes a status effect on a creature, it lasts until the next Initiative Count 20. As mentioned, they’re generally thematic to the lair itself, like magma erupting up in a Red Dragon’s lair, or furniture animating and flinging about in a vampire’s castle. While these actions have an impact on the battlefield, are generally weaker than the abilities of the creature, and they’re never effects that last more than one round.
Regional Effects
Finally, we come to regional effects. When a creature powerful enough to have a lair settles in an area, they can start to influence the environment miles out from where they’ve actually housed themselves. Regional effects generally can begin as far as 6 miles out in a radius around the lair. These effects do not directly target travelers as they enter, but certainly make it harder to get to the creature’s home. A white dragon summons blizzards to slow travelers. A Ki-Rin’s region has incorruptible water, and creature’s who fall due to no direct act from the Ki-Rin fall at a much slower rate. Regional effects are optional and at least add some flavor to a monster hunt, and at most can force the party to face hostile terrain on their way to interact with the creature. Sometimes these effects can be a plot hook in and of themselves - if a Red Dragon is summoning plumes of lava a mere few miles from town, the farmers’ crops aren’t going to be looking good this year.
Additional Traits
These are the typical attributes of stat blocks, but you may find it pertinent to add extra guidance. You may add references to the creature’s lore, their behavior in combat, their relation to general society, or their place of origin. Some of this lore can extend out to additional influences the creature has over other creatures or the world at large. It’s always recommended to give your creatures a place in the world beyond just another enemy to fight - it makes for a more engaging experience for the players and for the story you’re creating. But always keep in mind that you certainly don’t need elaborate lore for everything you make. You could make a creature simply because you think they’re cool and that’s perfectly fine.
Remember: stay consistent, stay fair, and make sure to have fun doing it.
