Saturday, 4 October 2014

D&D 5e Monsters: Part 8: Construction: Actions

D&D 5e Monsters: Part 8: Construction: Actions

Surf continues on into the final parts of the monster stat block...


Part 8: Construction: Actions

Some of these articles seem to take on a life of their own and grow longer in the writing. I originally intended to include the Attack Bonus analysis in this instalment, however I've decided to post this part on its own and continue working on Attack Bonus as its own separate article.

We will start with a general Overview of the different actions - Move, Action, Reaction and Bonus Action. From here we consider how we Build Attack Actions so that we can complete the stat block of our Example Monster.


Action Overview

Monsters are subject to the same action economy as player characters, although some monsters are able to extend this action economy in ways that PCs cannot - most notably Legendary Creatures. Just like PCs each monster can move and take one Action on its turn. And just like PCs monsters also have a Reaction and a Bonus Action that they may use, if they have a way of doing so.

Formally expressed actions use certain common elements to standardize documentation, though some actions may omit almost all of these components. The components themselves are pretty straightforward and tend to focus primarily on supporting attacks. These elements include the following...

  • Name: All formally presented actions start with a short descriptive name for that action, frequently this is a single word. For example "Bite".
  • Usage: Some actions are of limited usage and this is normally noted in braces immediately after the attack name. For example "Recharge 5-6".
  • Attack Type: Most attack actions employ a standardized short form to indicate the general attack range (for example melee or ranged) and type (for example weapon or spell), along with the keyword "attack". Common examples include "Melee Weapon Attack", "Ranged Weapon Attack" and "Ranged Spell Attack".
      Special attacks instead typically describe very briefly the attack type, range and shape. For example "The dragon exhales fire in a 60-foot cone".
  • Attack/Defense enumeration: Attack actions normally specify either a "to hit" bonus or details of a saving throw that the target must make. For example "+14 to hit" or "DC21 Dexterity save".
  • Target/Range information: Attack actions normally describe targeting information. For standardized short-form attacks this will be a range type (reach or range), a range outline in feet (including long range if applicable) and the number of targets. Examples include "reach 5', one target" and "range 120/360 ft., one target".
      Special attacks normally dovetail their action description into their target specification descriptively. For example "each creature in area" or "each creature that can see the..."
  • Hit/Miss section: These sections of attack actions describe what happens when the attack hits or, in some cases, when it misses. This section describes damage amounts, damage types, conditions and ongoing damage/conditions. It may also include nested attack sections, which are effectively additional attacks.



Move actions are not formally expressed actions in D&D 5e and are almost expressly not to be used for purposes other than movement. Indeed a number of monster actions which could be considered movement are implemented using Actions and Bonus Actions, such as the Etherealness action of the Ghost.

In D&D 5e the use of move actions is normally described in the Speed section near the very top of the monster stat block.



Combat-viable monsters almost universally have at least one Action and the majority of Actions are some form of attack, either as a direct attack or indirectly by enabling attacks, Multiattack being the most common of these.

Actions appear to fall in five specific categories and these always seem to occur in the following order with in the Actions section, when present...

  1. Multiattack
  2. Regular attacks
  3. Special attacks/Non-attack actions
  4. Limited use attacks
1. Multiattack
Multiattack. The dragon can use its Frightful Presence. It then
  makes three attacks: one with its bite and two with its claws.

Multiattack actions simply specify the name "Multiattack" and the other Actions which may be used when the creature's Multiattack action is used, including the number of times each may be used (if more than once).

The Multiattack action is one of the most common actions in D&D 5e and the mechanism by which many of this edition's monsters achieve the bulk of their Damage. The action's simple elegance makes it easy to tune in to the desired target damage range at design time and at game time allows the DM a good deal of flexibility dishing out damage with as much or as little focus as desired. We already see in the PC classes that increasing the number of attacks over levels is a common scaling method in D&D 5e and that may be one of the reasons Multiattack is so common in its monsters, but I believe it is also present specifically because of the control it yields to DMs and to monster designers.

The Multiattack action can be as simple as two uses of a single regular melee attack or as complex as five, or possibly more, different Actions.

2. Regular Attacks
Tail. Melee Weapon Attack: +7 to hit, reach 10 ft., one target.
  Hit: 18 (4d6 + 4) bludgeoning damage. If the target is a
  creature, it must succeed on a DC 14 Strength saving throw or
  be knocked prone.

Regular attacks are slim-line in design and implementation, generally steering clear of unnecessary complexity. These actions include a standardized short-form Attack Type, typically an Attack Enumeration of the "to hit" variety and short-form Target/Range Information. They generally also include a relatively simple Hit section, occasionally with a Miss section, and may include nested damage.

Almost all combat-viable creatures have at least one regular attack and many of the lowest CR creatures have nothing but regular attacks. In some cases regular attack actions are fallbacks used for things like opportunity attacks or as building blocks for Multiattack actions.

3. Special Attacks/Non-Attack Actions
Rotting Gaze. The nothic targets one creature it can see within
  30 feet of it. The target must succeed on a DC 12 Constitution
  saving throw against this magic or take 10 (3d6) necrotic

Special attacks and non-attack actions generally eschew the use of short-form annotation. By definition the more free-form Attack Type description is used and in most cases the free-form Attack/Defense enumeration and Target/Range information are also observed. Both the Hit section and Miss section may be present, but they may also be omitted in favor of a more free-form description, particularly in the case of non-attack actions.

Special attacks may account for a significant portion of a monster's alpha damage (aka "burst damage" or "spike damage"), especially where special attacks are conditional. However, in most cases alpha damage is the domain of limited use attacks or of the Spellcaster Trait.

4. Limited Use Attacks
Cold Breath (Recharge 5-6). The wolf exhales a blast of
  freezing wind in a 15-foot cone. Each creature in that area
  must make a DC 12 Dexterity saving throw, taking 18 (4d8)
  cold damage on a failed save, or half as much damage on a
  successful one.

Limited use attacks are those that specify a Usage restricting how frequently they may be used. Attacks of this type generally inflict damage well above that which the creature would otherwise cause and its normal damage is normally comparatively lower to compensate. In other respects the limited use attack typically resembles either regular attacks or special attacks.

The limited use attack is one of two vectors in D&D 5e for implementing alpha damage (aka "burst damage" or "spike damage"), the other normal vector being the Spellcasting trait.

Action Analysis

Now that we have examined the different types of Actions we need to consider the number of actions that are appropriate for a creature of our target CR. Is it just random (and by inference static with an acceptable margin of variance)? Or is there some kind of progression?

Common sense and instinct suggest that higher level monsters are more complex and thus more likely to have more Actions, but let's check the facts analytically.

Monster Number of Actions Scatter
Monster Number of Actions Scatter
Monster Number of Actions Average
Monster Number of Actions Average

Once we have recorded the number of Actions each monster has it's a relatively simple matter to create a scatter graph showing number of Actions by CR. Placing a trendline on this gives us an initial indication of whether there might be some kind of progression.

The graph suggests that there probably is a progression, although it is kind of difficult to tell exactly what. And the relative sparseness of our higher-level samples means the high CR end will be quite prone to skew. Still the shape of the samples tells us that a variation of +/-2 seems quite normal. In fact the Standard Deviation for this across all CRs is 0.89 and the average variability is 1.14. So we can be quite happy with +/-2 as our regular variation, understanding that there is scope to vary outside this if we feel that it's appropriate in a particular case.

Averaging the data out by CR and then producing a comparable graph reveals a likely progression. For the most part the data is quite well aligned and the progression itself is quite shallow. D&D 5e's preference for simple elegance shows itself here - even the more complicated monsters in the new edition tend to be relatively simple to understand and run. I find this a refreshing difference to its immediately preceding editions.

0 1
1 2
2 2
3 2
4 2
5 2
6 2
7 3
8 3
9 3
10 3
✝ Varies by +/-2

The summary graph tells us pretty clearly that a progression from 2 at CR1 to 7 at CR30 is probably appropriate and that we'd want to drop down to about 1 action somewhere around CR¼. How sure of this can we be? What margin is there for error? And how much does it matter if we are wrong?

Well we already mentioned the low Standard Deviation and Variability, which give us some surety. But as I said we are quite light on higher CR samples and this could skew that end of the trendline. Fortunately with such a short range of difference this is somewhat like Bounded Accuracy, we don't necessarily have to be exactly right - our margin for error isn't that big. Additionally these are only guidelines of what's generally appropriate at a nominated CR and we are designating a significant variation as standard so the impact of being out by a couple of Actions isn't big.

It only takes a couple of minutes to determine a linear progression that matches this pattern...
    Actions=0.17 × CR + 1.46

As a matter of practical advice I'd encourage monster designers to follow D&D 5e's principle of elegant simplicity wherever possible with Actions. Look to expressing your monster concept clearly with a small number of concise Actions where possible.

Prediction: I think most of what we have covered so far is self-evident. The only predication I can make is about the accuracy of the progression we have detailed above. I believe we'll find it's not too far off.



Just like PCs monsters have a Reaction they may use each turn and they can "spend" it in any of the standard ways - by readying an action, making an opportunity attack, dismounting as their mount falls or by using a spell with a casting time of "reaction". Some monsters can also use their Reaction in special ways, just as many PCs can, and if present this will be described in the monster's Reactions section.

Parry. The knight adds 2 to its AC against one melee attack
  that would hit it. To do so, the knight must see the attacker
  and be wielding a melee weapon.

The layout for a Reaction is normally its Name, an explanation of its trigger conditions and the details of the Reaction's results. While this might include any of the elements described in the Action Overview most Reactions tend to be fairly freeform, with a layout similar to the Special Attacks/Non-Attack Actions discussed above.

Monster Reaction Scatter
Monster Reaction Scatter
Monster Reaction Average
Monster Reaction Average

While most PCs manage to pick up a reaction by level 5 we find that Reactions are far less common amongst D&D 5e's monsters.

If we note the number of reaction entries each creature has and then plot the results on a scatter graph it's immediately obvious that very few monsters have a special Reaction. In fact of our 225 sample monsters only 7 have a Reaction (that's 3.1%) and none of these has more than one.

By averaging this data out and graphing it again we get visual confirmation of just how unusual it is for D&D 5e monsters to use special Reactions. Besides one tiny "blip" we can see that the overall average for any given level is close to zero, as it is across all levels.

This means that the use of special Reactions isn't something that monsters in this edition rely upon. We can probably simply consider it a flourish and as such a way of adding a certain "flavor" to the odd monster.

Based on the principle of elegant simplicity I believe we should not normally give our monsters special Reactions. Instead we should save these for when there is a compelling reason - perhaps we want a creature to "feel" like a Fighter or a Rogue and give it a Reaction similar to one that class has. Or perhaps our mental picture of the monster compels us to give it a special Reaction

Prediction: Special Reactions will remain quite rare as we see more monsters released by Wizards of the Coast.


Bonus Action

As monsters may take a reaction each turn they may also take a Bonus Action, if they have a way of doing so.

Rampage. When the hyena reduces a creature to 0 hit points
  with a melee attack on its turn, the hyena can take a bonus
  action to move up to half its speed and make a bite attack.

A monster's Bonus Action use is not detailed in a separate dedicated section, instead it is incorporated within other sections already discussed, typically the Traits section. A monster's Bonus Action may sometimes also be spent as a conditional extension of an Action.

While some Bonus Actions do enable additional attacks or Damage (which must be factored into the creature's average damage) some do not, instead they enable additional movement or other activity.

Monster Bonus Action Scatter
Monster Bonus Action Scatter
Monster Bonus Action Average
Monster Bonus Action Average

This brings us to consideration of Bonus Action progression and occurrence. Once again we tally up the number of Bonus Actions that each monster has and see what the data tells us. The first thing we see is that 24 of our 225 sample creatures (that's about 10.7%) have at least one Bonus Actions. And all but one of these have only a single Bonus Action.

The scatter graph of all samples makes this quite clear and we can see the CR2 Will-O'-Wisp clearly standing out above the rest. This tells us that most of the time our monsters won't need a Bonus Action, but if we choose to use one it should probably just be a single one. This is nicely in keeping with the principal of elegant simplicity.

The summary graph clearly reflects the approximate 10% occurrence of Bonus Actions and also reveals the low numbers of our high-CR samples, which results in some variability from about CR10 onwards.

Essentially monster mechanics which utilize Bonus Actions add complexity to monsters. If we consider the principals of elegant simplicity and easy operation together with the frequency of Bonus Actions it suggests we should think a little before using Bonus Actions on our monsters. If our monster feels a bit on the plain side and too simple maybe it's appropriate to spice it up a bit with a Bonus Action. If we want to give our monster the feel of a PC class maybe we could factor a Bonus Action into its composition.

Bonus Actions don't add the complexity of Reactions so with these I believe it's more a matter of using our judgment.

Prediction: Once the Monster Manual analysis is complete I believe we will see that the distribution of Bonus Actions stays at around 10% across all CRs, that said it is possible that it will increase somewhat at higher CRs.


Building Attack Actions

Building attack actions can be fairly freeform however there are some underlying construction guidelines we should observe, especially in the case of most regular attack actions.

Many monster designers feel more comfortable building monster attacks based on PC attacks and this works particularly well with weapon attacks. One selects a weapon, applies the appropriate modifier (Strength modifier for most melee weapons or Dexterity modifier for finesse and many ranged weapons) for to-hit and damage, then adds proficiency to the to-hit value. Monster size does appear to play a role here and that role seems to focus on damage dice.

TinyLight weapons only
SmallHeavy weapons excluded
Large2x weapon dice
Huge3x weapon dice
Gargantuan4x weapon dice

Weapon attacks seem to be impacted by creature size. Creatures smaller than medium appear to have restrictions on the weapons they can use and creatures bigger than medium size gain multipliers to the number of weapon dice. These modifications are clearest when looking at creatures assigned attack actions corresponding to weapons in the players guide. But this can also be extrapolated from other attack actions.

I have included a table with my understanding of these modifications. Please do note that this table is based on my observations and reflections. While these observations correspond with those made by other members of the D&D 5e analysis community (kudos to Coronoides from the forums and to others) they may not be a perfect match to what Wizards of the Coast is using. But it should be useful until we receive official guidelines from WotC.

Many creatures have attack actions similar to spells and many monster designers find it easiest to build these using PC spells as a base. The most important thing here is to ensure that the Spell Save DC or Spell Attack Modifier are appropriately calculated, using the appropriate ability modifier as the spellcasting modifier, as we discussed in the Spellcasting section of Part 6.

As monster designers gain more confidence building monsters in D&D 5e it's likely they'll tend to move away from reproducing PC attacks, except where appropriate, and instead move towards a more "pure form" of building monster attack actions. To those embarking down this path I would share the following notes and general pieces of advice...

  • Decide on the base ability and work out its modifier. For direct physical attacks it should be Dexterity or Strength. For magic, mental and other similar attacks it should be Charisma, Intelligence or Wisdom. Usually it's the highest ability in that group, unless there's a compelling reason otherwise.
  • Assume the monster has proficiency with their attacks, unless it suits design for them not to have proficiency.
  • To_Hit=Base_Ability_Modifier + Proficiency_Bonus
  • Save_DC=8 + Base_Ability_Modifier + Proficiency_Bonus
  • Damage always seems to have a base damage which is then built upon, which should be in the form
      NdN + Base_Ability_Modifier. For example 2d8+4
  • There is no mixed damage in D&D 5e, different types of damage in the same attack are concatenated. The base damage comes first with other damage appended to it. For example we would not have "3d8+2 fire and force damage"; instead we might have "1d8+2 fire damage plus 2d8 force damage".
  • It's legitimate to nest additional damage within base damage, typically using a save. For example "1d8+2 bludgeoning damage, the target must make a DC12 wisdom save or take an additional 2d8 psychic damage".


Example: Human Pyromancer

Applying this article's content to our example monster will produce a result that is essentially complete.

Human Pyromancer

Medium humanoid (human), any alignment

Armor Class 12
Hit Points 77 (14d8+14)
Speed 30ft

9 (-1)
14 (+2)
12 (+1)
19 (+4)
12 (+1)
12 (+1)

Saving Throws Dex +5, Int +7
Skills Arcana +7, Perception +4
Damage Resistances Fire
Languages Common, Ignan
Challenge 5 (1,700 XP)

Spellcasting. The pyromancer is a 5th-level spellcaster. Its
   spellcasting ability is Intelligence (spell save DC15, +7 to hit
   with spell attacks). The pyromancer has the following wizard
   spells prepared.

   Cantrips (at will): dancing lights, fire bolt
   1st level (3 slots): burning hands, disguise self
   2nd level (2 slots): invisibility, scorching ray
   3rd level (1 slot): fireball

Dagger. Melee Weapon Attack: +5 to hit, reach 5 ft., one target.
  Hit: 4 (1d4 + 2) piercing damage.

Flame Shroud (Recharge 5-6). When a ranged attack would hit
  the pyromancer, or it is targeted by a spell that has a range
  other than touch, the air around it bursts into shimmering,
  shifting flame for a few seconds. Until the start of the
  pyromancer's next turn ranged attacks against it, including the
  triggering attack, are made with Disadvantage and it has
  Advantage on saving throws against spells with a range other
  than touch. During this time it takes no damage from magic

Because we made a conscious choice to rely heavily on the Spellcasting trait for most of the pyromancer's damage we don't have a great deal to do in the Actions section. All we really need to do is to give it a melee attack action that it can use for opportunity attacks. To this end let's give it a Dagger attack.

A CR5 creature's Proficiency bonus is +3 and the dagger is a finesse weapon, so we'll use the dexterity modifier of +2 for this. There's no compelling reason to beef this up so we will just go with +5 to hit and 1d4+2 damage.

Now several times during these articles I have indicated that we would give our pyromancer some kind of "trick" against ranged spells and attacks. Something to help it get through that first round, until some of the PCs close on it. What I've had in mind is something like the Shield spell, however I see several issues with simply assigning the pyromancer Shield. First up our monster would be able to use this three times, not simply once. Secondly Shield works against weapon attacks, but doesn't provide any benefit against ranged spells. Finally Shield isn't fire-themed.

Because of the first two issues simply reskinning Shield isn't going to meet our needs. So we'll take what we can as inspiration from Shield, modify other parts and fill the gaps ourselves.

Shield is a reaction with a force flavor that gives a +5 defensive bonus until the start of the caster's next turn and nullifies magic missile. The +5 isn't much help against spells, but a +5 is about the same as advantage/disadvantage compared with a plain roll. So we can use advantage/disadvantage in its place and word a reaction that functions against ranged attacks, with a fire flavor.

If we imagine that the pyromancer is momentarily shrouded in shimmering fire that makes it difficult to target we can envision how this can all come together.

Finally we want to restrict use of this reaction somewhat so that it isn't used every round. We could make it a daily power, but I decided that it would be most interesting if there was a small chance the pyromancer could use it more than once per encounter, so I made it a recharge reaction.

Next time we'll look at how the pyromancer matches up to the to-hit curve and then we'll move on to assessing its actual CR.