This simplified method for handling encumbrance using an imprecise, medieval-mindset way of thinking about weight was originally designed in 2011 for OD&D and 3^rd Edition. This version of the rules is fully adapted for 5^th Edition.

Encumbrance, measured in stones carried, determines the load a character is currently carrying. A character’s encumbrance can be normal, encumbered, or heavily encumbered. A character has a carrying capacity equal to their Strength in stones (which is the maximum weight they can carry), they are heavily encumbered if they are carrying more than two-thirds of this number (round down), and encumbered if they are carrying more than one-third this number (round down).

Each character has an encumbrance rule to keep track of these thresholds, which are precalculated on the table below. For example, a character with Strength 10 has an encumbrance rule of 10-6-3 (meaning they are encumbered when carrying 3 or more stones, heavily encumbered when carrying 6 or more stones, and cannot carry more than 10 stones).

Encumbered: An encumbered character’s speed drops by 10 feet.

Heavily Encumbered: A heavily encumbered character’s speed drops by 20 feet and they have disadvantage on ability checks, attack rolls, and saving throws that use Strength, Dexterity, or Constitution.

Push, Drag, or Lift: A character can push, drag, or lift up (without carrying) twice their carrying capacity. While pushing or dragging weight in excess of their carrying capacity, a character’s speed drops to 5 feet.

Adjusting for Size: The encumbrance rule for a creature is doubled for each size category above Medium. The encumbrance rule is halved for Tiny creatures. (It is easiest to consider a Tiny creature as having half its Strength score for the purposes of calculating encumbrance, a Large creature to have double its Strength, and so forth.)

Variant – Quadrupeds: Quadrupeds can carry heavier loads and have an encumbrance rule equal to twice an equivalent biped.

WEIGHT BY STONE

To determine the number of stones carried by a character, simply consult the table below.

Miscellaneous Equipment: Up to twenty items of the same type (scrolls, arrows, potions, rope) can be bundled together for the purposes of encumbrance, with five bundles being equal to 1 stone. Items of different types aren’t bundled when determining encumbrance.

Stowed Weapons: Stowed weapons have been compactly stored in a way which makes them more difficult to draw (but easier to carry). Stowed weapons must be retrieved before they can be used, but they only count as 1 stone per 5 weapons.

Heavy Items: Anything weighing more than roughly 10 pounds can’t be effectively bundled. Estimate a weight in stones (about 10-20 pounds to the stone). When in doubt, call it a stone.

Clothing / Worn Items: Worn items don’t count for encumbrance, unless the individual items would qualify as heavy items.

CONTAINERS

Weapons are assumed to be in sheaths, armor is worn, and you might have a wineskin or two strapped to your belt. But since there’s a limit to how much you can hold in your hands, everything else you’re carrying needs a place to live. As a rule of thumb, containers can carry:

Empty containers count as miscellaneous equipment. Containers being used to carry items don’t count towards encumbrance.

Larger sacks (often referred to as “loot sacks”) are also possible, but these cannot generally be stored on the body. They must be carried in both hands.

VARIANT – CREATURE WEIGHT BY SIZE

Your own weight does not count against your encumbrance, but these figures are important for mounts. (They’ll also come in handy if you need to carry a corpse or prisoner.)

These figures are meant to serve as a useful rule of thumb, being roughly accurate for creatures similar in build and type to humans (i.e. fleshy humanoids). There will, however, be significant variance within each size category. Even typical animals of Huge size, for example, can easily range anywhere from 400 stones to 3,000 stones. Creatures of unusual material can obviously shatter these assumptions entirely (ranging from light-as-air ether cloud fairies to impossibly dense neutronium golems).

ENCUMBRANCE RULES

Part 2: The Sheet

ThinkDM recently wrote a blog post discussing the skill list in 5^th Edition called 5 Skill D&D. His two main points are,

First: The optional rules that allow you to roll any Skill + Ability combination should just be the way that the game works rather than an optional rule. I enthusiastically endorse this: Not only is it basically a no-brainer to take advantage of this flexibility and utility, but if you DON’T use stuff like Charisma (Investigation) checks then there are some glaring holes in the default skill list.

Second: Once you’re using these optional rules, it becomes clear that there are many skills that don’t need to exist. The most clear-cut examples of this, in my opinion, are Athletics and Acrobatics. One of these is Physical Stuff + Strength while the other is Physical Stuff + Dexterity. If you can just combine a “Physical Stuff” skill with the appropriate ability score, then you clearly don’t need two different skills for this.

Concluding that the game, therefore, has a whole bunch of superfluous skills, ThinkDM aggressively eliminates and combines skill to end up with a list of just five skills:

• Fitness (Athletics, Acrobatics, Endurance)
• Speechcraft (Persuasion, Deception, Intimidation, Performance (oration))
• Stealth (Stealth, Deception (passing a disguise))
• Awareness (Investigation, Perception, Insight, Survival)
• Knack (Sleight of Hand, Medicine, Animal Handling, Performance (instrument))

(Note: He eliminates the Knowledge skills – Arcana, History, Religion, Nature, Medicine – entirely.)

While I agree with the general principles here, I have some quibbles with the, in my opinion, overzealous implementation. So let’s take a closer look at some of these decisions.

I’M SOLD

I’m sold on Fitness, Speechcraft, and Stealth.

Stealth is fairly self-explanatory: Most of the conflation here actually happened before 5^th Edition was even published, which – as I’ve discussed in Random GM Tips: Stealthy Thoughts, among other places – is something I’m fully in favor of.

Lumping all the social skills into Speechcraft might initially seem too reductionist, but it’s another good example of how ability score pairings can be used to distinguish different uses of the skill and differentiate characters: Charisma + Speechcraft can be used for making a good first impression, seducing someone through sheer sex appeal, or swaying a crowd’s opinion through an emotional appeal. Strength + Speechcraft can be used for physically threatening someone. Intelligence + Speechcraft can be used for witty repartee. And so forth.

I’ve also found that this kind of conflation can sidestep the conceptual difficult of trying to figure out which skill is appropriate when someone tries to, for example, persuade the local garrison to join them by lying to them about the goblins’ intentions while subtly threatening to expose the garrison captain’s dark secret. (Logically the debate about whether this is Perception, Deception, or Intimidation should just shift to which ability score is the most appropriate; I’m just saying that, in my experience, this doesn’t usually happen. Don’t really know why, but people just seem more willing to let the muddy reality of most social interactions default to any appropriately invoked option when it’s ability scores. This also frequently flows in the opposite direction, with players moving away from one-note presentations of “this is my deception” or “this is me persuading her” to more nuanced portrayals within the broad rubric of a skill like Speechcraft. Your mileage may vary.)

I particularly like the name of Speechcraft. It has a nicely fantasy-esque feel to it; evocative, but not binding.

By contrast, I don’t like Fitness as the name for a skill. Fitness is not an action, but rather a state of being, and I don’t think it clearly captures the spirit of most such tests made at the table. I’d stick with Athletics.

AWARENESS

As I discuss at length in Rulings in Practice: Perception-Type Tests, I think there’s a lot of utility in clearly distinguishing between noticing things and actively investigating things. This becomes even clearer, I think, when you start combining them with different ability scores: Charisma + Investigation is canvassing information and rumor-gathering. Perception + Wisdom/Charisma, on the other hand, is reading body language and the like.

Lumping Survival in here doesn’t make any sense to me at all. The skill is a lot more than just following tracks and, in my opinion, should be important enough to most D&D campaigns to merit its own silo.

KNACK

Knack is all too clearly “here’s a bunch of skills I need to arbitrarily glom together so that I can hit an arbitrary clickbait title.” There’s little reason that the pick-pocket should also be the party’s best healer. Conversely, not everyone who is good at riding a horse should automatically be great at picking pockets.

So split those back out.

KNOWLEDGE

My personal proclivity is that not only should there be at least enough knowledge skills that everyone in the group can have a distinct expertise (which often means more knowledge skills than party members), but that there should be enough knowledge skills that it becomes quite likely that any given group will, in fact, have holes in their knowledge.

(Why? Because that forces them to either work around the gap in their knowledge, do research, seek out an expert, and/or set a personal goal to become the expert they need. And those are all interesting outcomes.)

As I mentioned above, ThinkDM eliminates all knowledge-type skills. He offers a contradictory hodgepodge of reasons for this (for example, “no one knows everything” but also “the GM should always just assume the PCs know everything”) which I could discuss at more length, but honestly I’m tired of explaining why failure is narratively interesting and delayed gratification is satisfying.

What I really want is for a knowledge skill list to completely cover the fields of knowledge in a setting. This doesn’t mean getting super granular in the distinctions (quantum mechanics vs. electromagnetics vs. optics). Often the opposite, in fact. When a question of knowledge arises in the setting, what I want is for there to be a clear skill check that can answer the question.

This is why I really dislike the incomplete fields of knowledge in 5^th Edition’s current skill list and much prefer 3^rd Edition’s comprehensive list. (3^rd Edition was also designed to let people custom-design knowledge categories, although a surprising number of people never understood that.)

If we want to slice down the knowledge-type skills, I’d say start by saying that Backgrounds should grant proficiency in any related Knowledge checks.

And then my list of knowledge-type skills would be:

• Arcana
• Religion
• Lore
• Knowledge: (Specific Location)

With Lore here covering the entirety of mundane knowledge.

Thus we broadly distinguish between mystic shit, god-stuff, and everything else. This gives the opportunity to spread Knowledge around the table (instead of just one guy who’s a smarty-pants) and gives players the ability to flavor their character.

We’ve also given people a chance to say, “I know this city or forest or whatever really, really well.” It’s a skill type I often reach for as a GM (regardless of system) and I think it can be very flavorful for players looking to define their characters or give them a unique niche.

THE BIG LIST

• Animal Handling
• Arcana
• Athletics
• Investigation
• Knowledge: (Specific Location)
• Lore
• Medicine
• Perception
• Religion
• Sleight of Hand
• Speechcraft
• Stealth
• Survival

If you want an even tighter list, you can:

• Merge Investigation with Perception
• Fold Medicine into Lore
• Drop Sleight of Hand into Stealth

To give you a nice, notable number with 10 Skills.

TOOL PROFICIENCIES

In 5^th Edition, of course, skills are only half the story. You’ve also got tool proficiencies.

You don’t have to muck about with these, but I think there’s definitely some conflation here that would be valuable, although it’s a lot more fidgety. (This is somewhat inherent in the decision to use tool proficiencies in the first place.) 5^th Edition already sets precedent for this, however, with things like Vehicle (Land) and Vehicle (Water) proficiencies which cover a multitude of specific tools/vehicles.

The question I have is why other obvious candidates likes Musical Instruments and Gaming Sets weren’t similarly grouped together into a single proficiency.

At a certain point in staring at this, though, you realize it probably makes more sense to just create a list of skills that require tools to use:

• Alchemy
• Art
• Craft
• Gaming
• Music
• Thievery
• Vehicle (Air/Land/Water)

With the following notes:

• Navigator’s and Cartography Tools would be conflated into Survival.
• Forgery Kit would be conflated into Stealth or Thievery.
• Disguise Kit would be conflated into Stealth.
• Herbalism Kit is conflated into Alchemy.
• Poisoner’s Kit is conflated into Thievery (although you could make a case for a separate skill).

To make this actually work, of course, you’ll have to do additional work on how characters gain skills. May not be worth the headache, so keeping this short list in a separate silo (which can be trained) may still make the most sense.

Sometimes you want to use your weapon or your martial arts skill to do something more than just lethally incapacitate a target. For example, maybe you want to knock the White Witch’s wand out of her hands. Or shoot a fleeing nobleman in the leg to slow them down.

1. Define the effect you want to achieve with your called shot.
2. The DM determines a penalty which will be applied to your attack roll (usually -2 or -4).
3. If your attack roll is successful, you deal damage normally and the target must make an appropriate saving throw (DC 5 + the margin of success on your attack roll) or suffer the desired effect.

GUIDELINES

Here’s some guidance for DMs making rulings with these rules.

STUFF YOU SHOULD VETO: This system is not designed to bypass the normal rules for combat.

I want to shoot them in the head! The effect you’re looking to achieve here is killing the target. We have a specialized set of rules designed just for that: It’s called “making a normal attack.”

I want to gouge out their eyes and permanently blind them! Like killing the target, permanent maiming in D&D doesn’t happen until you run out of hit points (and usually not even then). You can kick sand in their face or give them a cut that causes blood to run down into their eyes and temporarily blind them, but this system isn’t about inflicting permanent damage or disfigurement.

I want to paralyze them so that they can’t take any actions! This is probably too strong. You might make an exception if the PC is taking advantage of some specific environmental factor (e.g., making them fall backwards into a vat filled with sticky ethereal goo); this shouldn’t be something that characters can just automatically do without special equipment or a special ability.

Similarly, anything that would normally be handled by the Grapple mechanics should be handled through the Grapple mechanics.

EFFECT MECHANICS: There are a number of conditions which are appropriate for a called shot effect — Blinded, Deafened, Frightened, Prone, Restrained. Other effects could include the target being disarmed, distracted, or having their speed reduced. Lots of stuff can be mechanically modeled by giving the target disadvantage or another character advantage against the target.

THE PENALTY: In determining the size of the penalty, think about whether the desired effect is mild (-2) or significant (-4). Anything that requires the target to spend an action to remove the effect should probably be considered significant.

Circumstances can also affect the penalty. For example, trying to blind a beholder is probably a lot more difficult than blinding a cyclops. Alternatively, give the target advantage on their saving throw if appropriate.

DURATION: How long should the effect last for? As mentioned above, avoid permanent effects. If in doubt, go with 1d4 rounds or until the target takes an action to resolve the problem.

DESIGN NOTES

Why let the attacker deal damage normally AND create the effect? The goal of this system is to make combat more interesting by encouraging players to think outside of the “I hit it with my sword / I hit it with my sword again” box. By allowing them to both do damage and do something interesting, you eliminate the action cost penalty where players avoid doing interesting things because their best option is always to deal as much damage as possible and end the combat as quickly as possible.

Why a penalty? Because otherwise PCs would need to make called shots on every single attack. Which, if the goal is to make combat more interesting, might seem like a great idea. In practice, however, thinking up the called shot when circumstances don’t call for one or where you’re not inspired by a cool idea becomes a mechanical chore. And chores are boring.

Why not use disadvantage on the attack instead of a penalty? Whenever a character had disadvantage from another source, they would be mechanically incentivized to make a called shot every single time… which leads us back to the same problem above, only it’s more ridiculous. (“We’re fighting in the dark? Guess I should be making exclusively called shots to the knee.”) The problems associated with hard-coded advantage/disadvantage are discussed more in Untested 5^th Edition: Situational Advantage.

What about the existing mechanics for Shoving (PHB, p. 195) or Disarm (DMG, p. 271)? You can still use those mechanics in concert with called shots. Taking the Disarm action, for example, should make it more likely that you successfully disarm your target, but the cost is that you’re focusing your whole action on that.

I also generally recommend that DMs look at the “Contests in Combat” sidebar on p. 195 of the PHB and spend more time empowering and encouraging players to come up with cool uses for contests; which is more or less the same philosophy as this called shot system but with the PC spending their full action to accomplish the desired effect. I suspect that using these called shot rules will, ironically, ALSO result in the players forgoing their attack more often to focus on a contest. (Once you get players thinking outside of the box, they tend to continue thinking outside of the box.)

What about the Battle Master? The Battle Master’s Disarming Attack ability is mechanically similar to a called shot, but completely superior (pun intended): They suffer no penalty to their attack roll AND can add their superiority die to the attack’s damage roll. The DC of the target’s saving throw is calculated differently, but should generally be higher than a generic called shot with a disarm effect.

(I actually dropped the DC for called shots from DC 8 + margin of success to DC 5 + margin of success to help make sure the Battle Master’s mechanical edge was well protected here. Playing around with that value to make sure that called shots feel worthwhile, but without becoming more likely to succeed than the Battle Master’s maneuvers is probably the key thing to watch out for from a playtest standpoint. In a pinch, get the called shot DC right and then just give the Battle Master the option of using that DC if it would be better than their flat DC.)

Go to Part 1

Yesterday I rolled out some experimental rules for revising hydras and creating new hydroid creatures. Today we’re going to put them into practice with a few sample creatures.

Bear in mind that this is still an installment of an Untested column: The general rules for hydroids haven’t been tested and these specific monsters even less so. If you do find occasion to use them in your own games, please circle back and let us know how it went!

HYDRALING

Baby hydras — also known as hydralings – are two-headed serpents, only developing the legs of an adult hydra during adolescence. The mothers of hydralings have been seen to deliberately bite off one of the heads from their offspring, prompting the growth of an additional head. Some have hypothesized that this is because hydralings never truly sleep (since one of their heads is always awake), but it’s more likely an instinctual action which prompts (or is prompted by) the hydraling’s development.

HYDRALING
Medium monstrosity, unaligned

Armor Class 13 (Natural Armor)
Hit Points Special
Speed 40 ft., swim 20 ft.

STR 12 (+1)
DEX 15 (+2)
CON 12 (+1)
INT 2 (-4)
WIS 10 (+0)
CHA 6 (-2)

Skills Perception +3, Stealth +4
Senses passive Perception 13
Challenge 1/2 (100 XP)

Amphibious. A hydraling can breathe air and water.

Hydroid. The hydraling has two heads. For every 10 points of damage the hydra suffers, one of its heads dies. If all of its heads die, the hydraling dies.

At the end of its turn, the hydraling grows two heads for each of its severed heads, unless it has taken fire damage since the head was severed. A hydraling can have a maximum of five heads.

Multiple Heads. While the hydraling has more than one head, it has advantage on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious.

For each additional head beyond one, it gets an extra reaction that can be used only for opportunity attacks.

While the hydraling sleeps, at least one of its heads is awake.

ACTIONS

Multiattack. The hydraling makes as many bite attacks as it has heads.

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

TENTACULAR ABOMINATION

A dog-size creature with eel-like skin. It has no head, but its back is a writhing mass of tentacles.

TENTACULAR ABOMINATION
Medium monstrosity, unaligned

Armor Class 15 (Natural Armor)
Hit Points: Special
Speed 30 ft.

STR 17 (+3)
DEX 12 (+1)
CON 14 (+2)
INT 6 (-2)
WIS 13 (+1)
CHA 6 (-2)

Skills Perception +5
Senses Blindsight 60 ft., passive Perception 15
Challenge 3 (700 XP)

Pack Tactics. The tentacular abomination has advantage on an attack roll against a creature if at least one of the tentacular abomination’s allies is within 5 ft. of the creature and the ally isn’t incapacitated.

Hydroid. The tentacular abomination has five tentacles. For every 10 points of damage the abomination suffers, one of its tentacles dies. If all of its tentacles die, the abomination dies.

At the end of its turn, the abomination grows two tentacles for each of its severed tentacles, unless it has taken acid damage since the head was severed.

Multiple Heads. While the tentacular abomination has more than one head, it has advantage on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious.

For each additional head beyond one, it gets an extra reaction that can be used only for opportunity attacks.

While the abomination sleeps, at least one of its heads is awake.

ACTIONS

Multiattack. The abomination makes as many tentacle attacks as it has tentacles.

Tentacle. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: (1d6+3) bludgeoning damage. The target is grappled (escape DC 13) by one of the abomination’s tentacles. Until this grapple ends, the tentacular horror can’t use that tentacle on another target.

LENGLIAN SERAPHIM

Wings. Dozens of wings clustered together as if shielding a central mass (although no such mass exists within the impossible dimensional toroid of the Lenglian seraph), with eyes opening and shutting between the wings. Some Lenglian seraphs are also known to emit smoke or aurora-like, multi-colored halos as their wings continue to fold and unfold, stretching, reaching, searching, beating the air around them.

(It is also not unusual for Lenglian seraphs to be confused for a swarm of winged creatures, particularly from a distance.)

LENGLIAN SERAPHIM
Large celestial, lawful good

Armor Class 17 (Natural Armor)
Hit Points Special
Speed fly 80 ft.

STR 22 (+6)
DEX 21 (+5)
CON 14 (+2)
INT 21 (+5)
WIS 16 (+3)
CHA 19 (+4)

Saving Throws Wis +7
Skills Perception +7
Damage Resistance Radiant; Bludgeoning, Piercing, and Slashing from Nonmagical Attacks
Condition Immunities Charmed, Exhaustion, Frightened
Senses Truesight 120 ft., passive Perception 17
Languages All, Telepathy 120 ft.
Challenge 12 (8,400 XP)

Innate Spellcasting. The seraph’s spellcasting ability is Charsima (spell save DC 17). The seraph can innately cast the following spells, requiring only verbal components:

• At will: bless, detect evil and good
• 1/day each: augury, commune

Hydroid. A Lengling seraph has thirty-five wings. For every 5 points of damage the seraph suffers, one of its wings is severed. If all of its wings are severed, the seraph dies.

At the end of its turn, the seraph grows two wings for each of its severed wings, unless it has been splashed with unholy water since the wing was severed or is under the effects of a bane spell.

Many Eyed. A seraph has eyes proportionate to its wings. While the seraph has more than one wing, it has advantage on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious.

For every five wings the seraph has, it gets an extra reaction that can only be used for opportunity attacks.

ACTIONS

Multiattack. The seraphim can make one wing attack for every five wings it has.

Wing. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: (1d8+6) bludgeoning damage.

Radiant Gaze (Recharge 5-6). One creature that the seraph can see within 60 feet of it must make a DC 17 Constitution saving throw, taking 70 (20d6) radiant damage on a failed save, or half as much damage on a successful one.

LEGENDARY ACTION

Can take one legendary action. Only one legendary action can be used at a time, and only at the end of another creature’s turn. Spent legendary actions are regained at the start of each turn.

Buffeting Wings. The seraph beats its wings. Each creature within 10 ft. of the seraph must succeed on a DC 17 Dexterity saving throw or take 1d6+6 bludgeoning damage and be knocked prone. The seraph can then fly up to half its flying speed.

I woke up this morning with a cool idea for how to handle hydras in D&D. A quick check of the 5^th Edition Monster Manual, however, alerted me to the fact that 5^th Edition basically already did it that way.

Well played, 5^th Edition.

Upon further investigation, it became clear that my subconscious had dredged up a goulash of 3^rd Edition, 2^nd Edition, and OD&D mechanics and then regurgitated them.

Which, upon further consideration is a pretty good summary of the design methodology of 5^th Edition. (This is not a critique.)

Hydras, in D&D 5^th Edition, work like this:

Multiple Heads. The hydra has five heads. While it has more than one head, the hydra has advantage on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious.

Whenever the hydra takes 25 or more damage in a single turn, one of its heads dies. If all of its heads die, the hydra dies.

At the end of its turn, it grows two heads for each of its heads that died since its last turn, unless it has taken fire damage since its last turn. The hydra regains 10 hit points for each head regrown in this way.

The heads give a couple other advantages (extra opportunity attacks, it can sleep while still having one head awake to keep watch), but that’s the fundamental mechanic that models the classic hydra.

There are a couple of changes to this approach that I’d like to experiment with:

1. Eliminate the concept of “total hit points” entirely. You can’t kill a hydra unless you chop off all of its heads.
2. Tweak the mechanic so that you can eliminate more than one head per turn.

So if a fighter gets in there and deals 50 points of damage, his flurrying blades will have hacked off a couple of heads at once. Then maybe the rogue leaps onto its back, deals another 25 points of damage, and hacks off a third head. On the hydra’s turn, it will grow back six heads (two for each severed head).

REVISING THE HYDRA

Thus we can say that a hydra should be mechanically defined as:

• # of heads
• A damage threshold at which it loses a head
• At the end of its next turn or after X rounds it can regrow two heads if it has a severed head
• A sealing condition (usually a type of damage) that prevents
• Dies when it runs out heads.

The “Hit Points” entry of their stat block would be listed as “Special”: They only die if they run out of heads.

Here’s what our revised hydra special abilities would look like:

Hydroid. The hydra has five heads. For every 25 points of damage the hydra suffers, one of its heads dies. If all of its heads die, the hydra dies.

At the end of its turn, the hydra grows two heads for each of its severed heads, unless it has taken fire damage since the head was severed.

Multiple Heads. While the hydra has more than one head, it has advantage on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious.

For each additional head beyond one, it gets an extra reaction that can be used only for opportunity attacks.

While the hydra sleeps, at least one of its heads is awake.

CREATING HYDROID CREATURES

These mechanics can be used as the basis for other hydroid creatures. Here are some proposed guidelines for doing so.

Damage Threshold. This is the number of hit points required to chop off one of the hydroid appendages. These numbers are loosely based around the idea that a character of the appropriate level should be roughly capable of taking out one head per turn.

I’d recommend halving this value if the sealing damage type or other condition is an unusual one. (This would mean that the killing the monster would typically require killing the heads faster than they can grow back.)

# of Heads. Using the Creating Quick Monster Stats table on p. 274 of the Dungeon Master’s Guide, multiply the minimum hit points for your selected CR by 0.75 and then divide by the damage threshold listed above for its CR.

For example, a CR 10 creature would have 206 hp using the table above, so multiply by 0.75 (154) and then divide by 25 (per the damage threshold table above) to determine that your monster should have six heads.

(This is based strictly on reverse-engineering the existing hydra stat block and it’s unclear if it holds up in practice. It seems to pretty reliably give you 4-8 heads, so you could also probably just get away with slotting in 5-6 heads and not worrying about it.)

You can also use this method to very quickly adapt existing stat blocks. For example, if you wanted to have a hydroid warg (CR ½) you’d take the warg’s current hit point total of 26, multiple by 0.75 (19.5), and then divide by 10. The hydroid warg would start with two heads.

Variant: Maximum Number of Heads. In 2^nd Edition, Lernaen hydras could grow maximum of 12 heads. In 3^rd Edition, they were limited to no more than twice its original number of heads. You might consider doing the same for some hydroid creatures.

DESIGN NOTES

Hydras have a well-known gimmick: They regrow their heads unless you cauterize the stumps with fire. It’s a fun gimmick the can create an encounter which mechanically feels different from other encounters. The only problem is that, because the hydra still has a hit points that’s easier to wipe out than its heads, the mechanical gimmick is irrelevant: There’s often little or no advantage to pursuing it, so parties will just bypass it.

This is boring.

So we fix it by eliminating the bypass. Just like you can’t bypass a troll’s regeneration by just dealing lots of hit point damage to it, you can’t bypass a hydra’s heads.

And, just as regeneration mechanics were created for trolls and now underlie a whole bunch of creatures, these hydroid mechanics can also be used for all kinds of things. We’ll take a look at several examples of this tomorrow.

Go to Part 2