How to Create a Monster for Revised D&D 5E 2024

The 2014 DMG provided us with a step-by-step process guiding us through creating monsters. It included everything from a table of statistics by CR to a set of features we could add to modify monsters. That’s all gone… so let’s rebuild it for 2024! (A video supporting this blog can be found here.)

Two Ways to Create Monsters

There was both a quick method and detailed method in the 2014 DMG. The quick method was of lower utility, though arguably superior to the sparse monster creation information in the 2024 DMG (which I walk through in this video).

As DMs, we should absolutely have in our DM toolbox an approach for quick monster creation (for use at our tables, not in published works). Rather than the 2024 DMG’s approach or even what 2014 aimed to do, I would suggest one of the following:

1. Use the simple “Building a Quick Monster” system in Forge of Foes.
2. Use the Monster Statistics by CR table below and just improvise what the attacks represent.
3. The following slightly more complex process, adjusting to your style (again, this isn’t for publication):

• Choose an existing monster as your start. This is easier if it has a CR close to your target CR. Maybe it’s a weird amorphous otherworldly being? We look through the oozes and pick one that has similar concepts and/or a similar CR.
• Review the existing monster and subtract out features (traits or actions) you don’t want. Keep track of the number of removed features that are useful in a fight. Maybe we removed two useful features from our ooze.
• Add a similar number of features from other creatures or your imagination – CRs need not be the same. Try to have an equal number of features added/removed so the creature remains easy to run and of similar capability. Maybe we add two features to our ooze, taking them from a lower CR ooze.
• Review all features against our Monster by CR table (see below) and update them if needed to match the expected statistics for our CR. For our ooze, we update the math of our added features to its CR.
• To represent a concept, you can move up or down the table in some category (such as AC) and compensate in some other category of similar importance (Attack Bonus). We decide our ooze’s otherworldly texture is hard to damage and increase the AC, but we lower its Attack Bonus.
• Because this is for home play, you can make additional changes based on your style and what you know about your players to create the most fun at the table.

Monster Statistics by CR Table

The following table is based on my analysis of the math in the 2024 Monster Manual, comparisons to the 2014 DMG monster by CR table, and analysis by Tom Dunn and Paul Hughes.

I also refer to Forge of Foes, and this table includes material taken from the Lazy GM’s 5e Monster Builder Resource Document written by Teos Abadía of Alphastream.org, Scott Fitzgerald Gray of Insaneangel.com, and Michael E. Shea of SlyFlourish.com, available under a Creative Commons Attribution 4.0 International License. This table is big, so I suggest clicking on the link to get the bigger version and then viewing that larger image while reading the rest of this article. Patreon supporters get this and other tables as part of the Adventure, Encounter, and Monster Design Tools.

A few notes:

If you happen to use Forge of Foes, congratulations! You can continue to use that table for your games and follow that guidance. Forge of Foes was designed first and foremost to make your games fun, rather than to reflect WotC specs. If you are working towards publication and wish to reflect the 2024 monster math as closely as possible, then I suggest this table (because Wizards of the Coast hasn’t provided us with a new official table).

In the table, there are a few header acronyms. Pub = Published. FoF = Forge of Foes. TD = Tom Dunn, from his blog. Leg = Legendary. I provide several columns for HPs so that you can compare both the published range and average to what Forge of Foes recommends. For Damage, I provide both an average and Tom Dunn’s averages for normal monsters and then a legendary monster DPR which increases his normal damage by 25%.

This table is not perfect. The why of it is pretty geeky. I built this table primarily through the painstaking work of averaging out every single monster in the 2024 MM. Then I looked at the results and tried to make that into a reasonable table. The average AC should stay the same or increase as the CR increases… even if the actual MM monsters don’t do that. And, I had to at times make changes to adjust for what seem to be divergent monsters. See, any given monster has a concept that may cause it to deviate from Wizards’ version of this table. We don’t want every monster to be the same. A big giant is easy to hit, so it may have a lower AC and far more HPs than the target for its CR. A creature that is clumsy may have a low Attack Bonus but deal much more damage when it actually hits. Paul Hughes does some nice work to plot a line through all the values so we get a reasonable progression, so I checked my numbers against his and made adjustments. So, in this table you will find some items in red, which indicate I made adjustments. Patreon members also get this table in my Adventure Tools spreadsheet with a few extra comments and various other tables.

Let’s get even geekier. Tom Dunn found that many monsters have powerful defensive or offensive features. Sure, a creature has AC and HPs. Take a look at the Tarrasque. It has Magic Resistance and Reflective Carapace, defensive features that prevent damage, potentially equivalent to having several hundred more HPs. This is really hard to reflect in a table. If the table read 900 HPs, that would be strangely more than a Tarrasque, and I would need to give you complicated instructions to go and remove several hundred HPs and replace them with defensive features. And we would need to do this for damage as well.

I chose not to do this. Instead, I tried to reasonably stick to the printed statistics and instead tell you the following: After you build your monster, compare it to existing ones of that CR (matching legendary or non-legendary when possible). Try to create your monster so it has a similar number and type of defensive or offensive benefits as those same-CR monsters. For example, you might see a monster that can easily knock targets prone, but has a low Attack Bonus. Or, you might see that a creature has lower HPs but has spells it can use to get out of trouble or protect itself. You could emulate that approach. What you want to avoid is creating a monster that follows the table and then has powerful offensive/defensive features without reflecting how similar monsters are handled. Make sense?

How to Create a Monster for Revised D&D 5E 2024

To create a monster from scratch, and particularly to do so as closely as possible to Wizards of the Coast standards, follow this process. (I am basing this on a chapter we considered adding to Forge of Foes but ultimately did not use. I thank Mike Shea and Scott F Gray for their feedback on that original draft, which I have modified further.)

Start with CR

Even if just a loose concept, I recommend having a target CR in mind from the beginning. You may end up changing it in the process. An easy way to do this is think of a comparable monster you know and look up that CR. Maybe this is as dangerous as an Ogre, or a powerful outerplanar creature like a Solar.

You could instead work with the statistics and find out the CR the creature has earned. If the end CR doesn’t work for your purpose (especially if this monster will be used in an adventure with a particular level range) you can raise or lower the CR at the end of the process.

Concept and Basics

Monster creation begins with a concept and a name. First and foremost, imagine the monster and how it fits into your games. Try to visualize it or describe it in a paragraph or two, or jot down a few key aspects.

Select the Monster Type (such as elemental or undead, a full list is in the Monster Manual and Free Rules) and the Size. Size will determine Hit Dice – a Tiny creature will use a d4 for Hit Dice, all the way up to a Gargantuan creature using d20s. (Hit Die size is an excellent example of something that has very little relevance at your gaming table, but would be important to get right if you were preparing a monster for publication.) You can also assign your monster an alignment, following the approach in either Monster Manual. Other touches include skill proficiency, senses, and languages, all of which we are told do not impact CR.

Ability Scores

This is one of the fascinating sections of the 2014 process, because there was almost no guidance for ability scores. The rules provide an ability range from 1 to 30, and suggest looking at similar monsters to pick a score. Ability scores can be used to determine several mechanical aspects (though it is sometimes optional to do so under 2014 rules but common in 2014 and in the revised official design). Ability scores also come up during play when there are ability checks, saving throws, and contested checks. Because of this, you should at least take some time to think through what the ability scores should be. I personally recommend Keith Ammann’s The Monsters Know What They’re Doing, or one of his follow-up books, as they give the best examples I’ve seen of what a creature’s ability scores tell us about the creature.

Ability score bonuses to attack, damage, Hit Points, or Dexterity (and possibly AC) can all impact statistics in the table. Therefore, you may end up needing to come back to this step and adjust ability scores to hit the right CR. The most annoying of these is recalculating Hit Points from Constitution, for which I recommend the tool I provide to Patreon supporters.

Armor Class

The Armor Class can be derived in one of two ways. You can simply look up the AC in the CR table, and use that value and adjust it to fit the concept. For a CR of 6, the suggested AC is 16, but your creature is made of stone and you might decide to make the AC higher to represent that.

You can instead calculate the AC based on the armor the monster wears, its natural armor, or a spell such as Mage Armor. You then add in the creature’s Dexterity bonus (unless the type of armor would not allow the bonus). For creatures not wearing armor, you are again left to determine a proper value for the natural armor bonus. We recommend comparing the characteristics of the creature’s skin or hide to that of armor types. Is the stone creature’s skin tougher than plate armor?

These two approaches can provide you with very different results, but there is no official guidance on which to use. In the end, you should look at the value and decide whether it fits the fiction behind the creature. Is it highly mobile? Is it enormous and hard to miss? Is it an accomplished warrior, capable of blocking attacks? A logical AC will lead to better play.

The official rules also fail to coach us on how AC impacts play. A monster that is hard to hit can be frustrating. One that is easy to hit can increase the fun, but may die before it gets to show off its capabilities. When deciding whether the final AC value is appropriate, think about the role this kind of monster may play in a typical encounter (and see the Forge of Foes Monster Roles chapter for more thoughts on the topic).

Hit Points

As with AC, two ways are provided to determine Hit Points, with very little guidance over why one method should be used vs another.

You can again use the CR table, which provides both an average and a range of expected HPs. In a home game, you can simply pick a number. If you ever need to know the creature’s Hit Dice for something such as a monster spending Hit Dice to heal, you can use its size to determine the die size and roll a handful of dice.

The second option is to fully calculate the Hit Points and Hit Dice. You use the creature’s size to determine Hit Die size (Tiny d4, Small d6, Medium d8, Large d10, Huge d12, Gargantuan d20). The rules suggest picking a number of dice that feels appropriate. In a manner similar to a character level, the monster gains its Constitution bonus in Hit Points for each Hit Die. Use the average of the Hit Die as the Hit Points it gains from each die. A d8 has an average value of 4.5. A medium monster with 6d8 Hit Dice and a Constitution bonus of +1 will gain 5.5 Hit Points six times (4.5 + 1 = 5.5) for a total of 33 Hit Points (6 X 5.5 = 33).

When using the second method you should compare your result to the table. The creature should not be vastly different from the range for its CR unless you plan on compensating in other ways (typically with AC, defensive features, or contrasting being quick to die with higher damage). Because of the work it can take to revise Hit Dice (or in rare cases the Constitution score) until a proper value is found, the first method of simply using the CR table is easier for a home game and the more complex method is appropriate for publication.

Adjustments to Effective Hit Points

The 2014 core rules tell you to take into account whether the creature has resistances or immunities to damage types (condition immunities do not impact CR, according to the 2014 guidance).

The real measure is whether the player characters are likely to be impacted by the damage resistances or immunities. If they will not be impacted, then you can ignore these adjustments. If they will be, or if you are creating the monster for publication, then the effective increase is worth considering.

If the creature is to have resistances or immunities to several damage types expected to be relevant (in particular to bludgeoning, piercing, and slashing), a table in the 2014 DMG provides you with a multiplier you can apply to the creature’s Hit Points. A CR 2 creature with 33 Hit Points and several resistances has effectively 66 Hit Points. Effective Hit Points are considered later in the process. What does WotC do in 2024? WotC seems to only lower the HPs of a monster due to resistances when it is resistant to physical damage or from immunities when it has three or more damage immunities. Having any number of non-physical resistances or under three immunities does not impact CR. I recommend following their rule.

Just as importantly, resistances, immunities, and vulnerabilities all tell a story. They work well when you draw attention to them. You may surprise characters initially with a golem immune to most damage, but the real fun comes when the characters discover exactly how to defeat the monster and discover its vulnerability. The end result may not be any change to the Hit Points, but can be a huge impact on fun.

A monster may also have various defensive features, as in the example above of the Tarrasque. Defensive features that will have a significant impact on survivability should likely result in lowering either HPs or AC. Again, think through the fiction of the monster and how to make that feature (such as a reflective carapace) salient. I recommend first thinking of the fiction of the monster and assign defensive features if the fiction calls for it. Then, look at official published monsters of the same CR. If the number of defensive features and HPs are reasonable, you should be fine as-is. If you have more defensive features, lower your HPs (or, alternatively, your AC). If you lack defensive features compared to other monsters, either increase your HPs (or AC) or add defensive features similar to those found on same-CR monsters.  

Attack Bonuses

The rules allow you to either use the CR table’s Attack Bonus or to calculate it based on either the creature’s Strength or Dexterity.

As with previous steps where you get a choice, the benefit of the calculation is not clear. Players are unlikely to know that the monster is hitting more or less often because of its ability scores. Instead, what matters is the story the overall accuracy tells. An accurate monster is skilled, precise, accomplished. An inaccurate monster can feel inelegant and imprecise. You can combine this concept with its damage to create a great story. You may design a giant shark that takes huge bites that often miss, but leave their target badly wounded when they hit. A trained soldier hits often with precise and measured blows, slowly whittling down their opponent. Not all official monsters follow this line of thought, but it is worth considering as a means of expressing the fiction behind a monster. 

Damage

You can again use the CR table or calculate damage based on the weapon and ability score. The CR table provides the total damage a creature can inflict in a round, averaged across all its attacks. For official design, this average is calculated across three rounds, allowing for capture of limited use or recharge actions, as well as situational capabilities. When you choose your actions, it is useful to think of the official three-round average, but also to consider longer battles and how the creature will use their attacks in longer battles. You can compare your design to other creatures (including the averages I provide in my Patreon tools).

You can ignore actions the creature is unlikely to use, though it is best to design monsters so they have only useful actions. Once you pick your actions you can compare the average damage to the CR table to note whether it deviates from the expected range, adjusting if necessary.

The damage type should match the weapon or type of attack. You can also break up damage, with part of it being piercing and part of it being poison damage, for example, to reflect a creature with poisonous fangs or a rogue with a poisoned blade. This is very common in 2024 design. For creatures with natural weapons, you are told to base the damage on similar creatures. So, look up what other similar clawed creatures or biting creatures deal and then scale the damage up or down with more dice or a larger static bonus.

No advice is given on dice vs static damage. Aim for a reasonable number of dice to have on hand and to represent the feel of the attack. Spells and AoE tend to roll more dice. Really dangerous attacks can feel that way by rolling more dice. Rolling more dice increases the swingy nature of the attack, with possible very low damage and very high damage (including on crits). Think about the variance you want to achieve and whether the attack should be variant (a bite that just catches a part of its target).

When a monster uses an action that targets several creatures, the rules assume just two targets will be hit. You can therefore halve the damage a monster would deal when hitting one target and use that value as the damage for a multi-target attack. Limited use actions, such as those that recharge or are highly situational, tend to deal four times the damage of an action that is not limited. However, this can make your monster more dangerous. When you give your monster a 120’ cone, and the monster can easily maneuver, or if the AoE is a 60’ emanation… chances are the AoE will get most party members, which massively increases the damage. (See my video on the math of 2024, as well as videos discussing specific monster tactics and how AoE damage will likely end up much higher.)

Actions and Multiattack

The advice for both attack bonuses and damages doesn’t say much about the types of actions to create for a monster. You should again dive into the story of the creature and how it should engage in battle. I recommend a creature always have an effective melee and ranged option, unless the creature should truly be incapable of ranged options.

Consulting monster books, myths, novels, movies, and other inspiration helps. A giant lizard may have a bite, sure. But maybe it should also grapple or swallow a target it bites. Or maybe it should be able to swipe a creature with its tail. Maybe it can spit poison, or leap and come down onto a creature, pinning it. You want actions to convey the essence of the creature.

We can’t use all our ideas. You want to narrow the list of actions to just a few. A battle typically lasts only three to five rounds, so the monster should have no more than five actions and typically three will suffice.

When designing actions, consider whether the monster’s main attacks should be a single big hit or a Multiattack action consisting of several attacks. This may be the same attack action multiple times, or a combination of actions. Multiattack results in a smoother expected damage curve, with more chances to hit but each hit is for smaller amounts. The CR table has an entry for the expected number of attacks in a Multiattack action. Consider also the attack bonus. A single attack with a low bonus can feel disappointing, but a single attack with a high attack bonus may be okay. Don’t forget the d20, however. A string of three bad rolls when the monster has three attacks a round is not as bad as a string of three bad rolls across three rounds of play.

Because reliability is fun, most monsters above CR 2 have multiple attacks. Go with the concept that fits the story, but if in doubt choose a Multiattack so the monster is more reliable.

Initiative

2014 placed low importance on Initiative. In 2024, more monsters receive proficiency and even Expertise in Initiative. We have no guidance on this. What I would suggest is deriving the Initiative and then deciding whether this creature has the cunning or training to act faster than most monsters of its type. And, whether its role in battle (including being a boss) should drive a boost. A higher initiative is going to help that monster last a bit longer and inflict a bit more damage, but it does not appear to change a monster’s CR in official 2024 design.

Saving Throw DCs

You can use the table or calculate a saving throw by adding 8 plus the foe’s relevant ability score and their Proficiency Bonus. If you calculate the DC, compare it to the table to see how far off you are. If you know your players, you can be better prepared for whether the DCs will be too high or too low. Official design sometimes has one DC for spellcasting and one for breath weapons or other effects, because they see the fiction tying a specific action to a specific ability score. However, this adds complication to a DM and you may wish to set every DC off of the most relevant ability score to make the monster easier to run.

Special Traits, Actions, and Reactions

The 2014 DGM provides an extensive table of “Monster Features” and whether those should alter the CR. For example, a tiger’s Pounce feature increases its effective damage for 1 round, but invisibility does not usually impact CR.

These are good estimates, and worth using with 2024 design, but consider how these interact with other elements of the creature. When considering such additions and whether they impact CR, consider how often they will be useful and whether they feel like an actual boost to the monster’s ability to survive or deal damage. If you are creating a creature for an encounter, you can consider that interaction as well. The ability to push foes may present a very minor benefit in most cases, but a strong benefit when fighting at the edge of a cliff or in a room where the floor is riddled with damaging terrain.

Speed and Saving Throws

The 2014 rules state that a flying creature has an effective AC that is 2 higher if it will gain a benefit and the characters can’t mitigate it. This can also depend on the encounter you design or whether the flying creature can attack effectively at range or ignore opportunity attacks. I personally tend to think flying is not a huge effect unless abused. That Chimera is much stronger if you intend for it to never land and to face character levels where PC flight is uncommon… but in most cases the adventures result in the monster being within reach most of the fight.

If you add a bonus to a saving throw, it should be equal to the Proficiency Bonus and the ability score bonus for that saving throw type. If you do so for three or more saving throw types, this raises the effective AC by two. However, this 2014 advice may not line up with current design. When in doubt, check the CR table and go with those ranges. If you are substantially higher, you may wish to increase the CR or reduce some other aspect of the creature, such as Hit Points.

Legendary Monsters

If you are creating a Legendary monster, the easiest change to make is to keep HPs as a normal monster and to boost your DPR by about 25%! So, when designing a Legendary monster, it should hit harder.

When I first wrote this blog, I included a column with HPs for Legendary monsters, but analyzing this further with Tom Dunn, we think the nuances of Legendary HPs are too hard to capture. There are too many CRs where there are too few monsters to properly compare – either just one Legendary or just one Normal, and insufficient monsters overall. Arguably, a Legendary monster has slightly lower HPs, but not enough that I recommend using a different HP value.

Your legendary monster should have a Legendary Actions block in its statistics, modeled after creatures of a similar CR. Most creatures have three legendary actions and the stat block provides 2-4 options. Most legendary actions include one that can be used all the time, typically to use one of the attacks in its Multiattack (often one that can be used at range). And, it is worth having a more powerful feature, which may have the text, “This creature can’t take this action again until the start of its next turn.” (Replace “This creature” with the name of your creature.) Consider having at least one legendary action that provides mobility options, allowing a boss monster to move out of trouble or closer to targets. In addition, most legendary creatures have a Reaction, Bonus Action, or both. This provides further opportunities to achieve more stable damage output and respond to tactical situations.

Comparing Offensive and Defensive Challenge Ratings

The 2014 DMG process now instructs us to compare the defensive features and the offensive features of the monster. We can still use this process for 2024 design.

To add up your Defensive CR, first look at the monster’s Hit Points and find the CR on the table that matches that hit point total. Then examine the AC to see if your creature has the same CR as expected for that row. For every 2 points of AC higher or lower than expected, alter the CR by 1 point. This becomes your defensive CR.

To calculate your Offensive CR, Take the average damage the creature inflicts across three rounds and look up the CR matching that value. Then look at the attack value for that CR. For every 2 points higher or lower than your attack bonus, alter the CR by 1. You should instead use the Saving Throw DC column if your monster primarily uses saving throws (for spells or other effects) to determine its damage.

Finally, add the offensive and defensive CRs together and divide by 2 to derive the average CR. This becomes your new CR. Look up your new CR in the table and use the proficiency bonus and XP value for the newly determined CR and assign those to the monster (revising skills and other values as appropriate). You are given guidance for selecting skill proficiencies, condition immunities, senses, and languages.

Is this 2014 process still worth following? It can be worth deriving the average CR and then pausing to consider if this works for this specific monster (given its other statistics and fiction). You may wish to make adjustments to bring the CR back to your desired number. In a home campaign, you can use your judgment as to whether it truly needs a new CR based on what you know about your characters. This process places greater weight on HPs than AC and on DPR over Attack Bonus. It is unclear whether that is still in line with official internal 2024 design principles.

In particular, 2024 monsters seem to at times vary significantly from the HP range (perhaps due to defensive features) and other statistics (even DPR) for their CR. For example, CR 8 monsters in the MM have 135 HPs on average, but the Assassin has just 97 HPs (similar to CR5 or 6 monsters) and the Hydra has 184 (higher than the average for CR 10). This may reflect a more complex calculus they use internally.

All this means is that some variance is okay. You can aim for the table and be fine, or be a bit higher or lower without being outside expectations. You can use the comparison of offensive and defensive CR as a check in your process to verify you aren’t drastically out of line with your CR.

Same CR, Different Monsters

The calculation of offensive and defensive CRs, and how they are averaged together, helps us understand how two monsters may feel very different during play despite having the same CR.

A monster with low AC but high Hit Points is hit often but seems to last a long time. A monster with high AC but low Hit Points may dodge several blows, but drops with fewer hits. A monster may have high Hit Points and high AC, but possess a key vulnerability or deal low damage. These combinations create vastly different play experiences and it is worth considering them when you review or create a monster.

A Hope for the Future

In the near future, Wizards of the Coast will release its SRD for 2024. My hope is that it will recognize the value of helping creators create the best monsters possible. This will improve third-party design, making D&D overall a better game and better play experience. Thus, I hope the SRD will finally include a version of the 2014 DMG guidance and tell creators how to officially create monsters. Until then, I hope this guidance is helpful. If this has been helpful, please consider joining my Patreon and our awesome Discord community!