[5E] Monster Manual Variant

[virgil]

Long story short, I want to have a more consistently designed monster manual. However, I'm not as experienced with 5E's functional dynamics to properly estimate some of the numbers, and I'm wanting some opinions of what I've got crafted thus far.

Goal: To write up a monster manual around more guidelines than what 5E did, with an eye toward better encounter design.
5E Monster Manual Revised Tiers
Gameplay can be roughly estimated to fall into four tiers.
[*]Tier 1 Levels 1-4
[*]Tier 2 Levels 5-10
[*]Tier 3 Levels 11-16
[*]Tier 4 Levels 17+
Encounter Design
A standard, challenging encounter is derived from both party size and level. Every two PCs justifies the use of either three thugs, eight mooks, or one elite of the same tier. If a monster is from a higher tier, then they are upgraded to the next step up the threat chain. For example, an appropriate encounter for a Tier 2 party of four players could potentially be
[*]2 Drakes
[*]2 Griffons, 1 Blink Dog, 8 Spinagon
[*]1 Unicorn, 3 Pegasi, 4 Riding Horses
If a monster is rated lower than a mook, such as a Tier 2 party fighting lemures, do not add use more than four lemures per character. The aggregate numerical advantage is too strong to accurately assess in a balanced manner.
Levels 1 & 2: Due to the particularly low capability of the first two levels, halve the available monsters for design for the first two levels. Thus, a level 1 party of four PCs can fight a single ogre or eight lemures.

Types & Subtypes
There are traits associated with each type, barring rare circumstances, the abilities of which will be repeated on the creature’s entry.

• Beast Intelligence of 2 or lower
  Fiend Resistant to Necrotic Damage
  Demon Resistant to Acid, Cold, Fire, & Lightning damage
  Devil Darkvision, Devil’s Sight (Darkvision is unhindered by magical darkness), Immunity to Fire damage, Resistant to Cold
  Mindless Condition Immunity to Charmed & Frightened, Immune to Psychic Damage, Intelligence of 1
  Celestial Resistant to Radiant Damage
  Formless Resistant to nonmagical damage, Condition Immunity to Grappled, Petrified, Prone, Restrained
  Fey Resistant to Magic (Advantage on all saves against spells & other magical effects)
  Undead Immunity to Necrotic damage, Vulnerable to radiant damage
  Unliving Condition Immunity to Fatigued, Exhaustion, & Poisoned; Immunity to poison damage
  Mount & Pet These two aren’t types so much as placeholder notes for their intended environment and are typically expected to be on the lower end of power for their category.

Tier 1 Mooks

• Cat [Beast, Pet] 2hp (1d4), AC 12, Spd 30’/climb 20’, Claws -2 (1); Stats 3.15.10.3.12.7; Stealth proficiency, Darkvision
  Owl [Beast, Pet] 1hp (1d4), AC 11; Spd 5’/fly 60’; Talons -2 (1); Stats 3.13.8.2.12.7; Stealth proficiency, Keen hearing, Darkvision, Flyby Attack
  Lemure [Outsider, Fiend, Mindless, Devil] 7hp (2d6), AC 7, Spd 15’, Slam +1 (1d4-1); Stats 8.5.11.1.11.3; DV 60’, Devil’s Sight, Resistant to Necrotic & Cold, Immunity Charmed & Frightened, Fire/Psychic Damage
  Dretch [Outsider, Fiend, Demon] 5hp (2d6-2), AC 10, Spd 30’, Slam +2 (1d3); Stats 11.11.8.5.8.3; Resistant to Necrotic, Cold, Fire, Lightning; Immunity Poison & Poison Damage; Stench (1/day, 1 minute, 10’ radius, Con DC 11 or poisoned & sickened until start of next round)

Tier 1 Thugs

• Riding Horse [Beast, Mount] 19hp (3d10+3), AC 10, Spd 60’, Hooves +2 (2d4); Stats 16.10.12.2.11.7; Trampling Charge (20’ + attack = x2 dmg + Str DC 13 or be knocked prone)
  Chocobo [Beast, Mount] 13hp (2d10+2), AC 12, Spd 60’, Beak +5 (1d8+3); Stats 16.14.12.2.11.7; Rush (Can Disengage & Dash as one action)
  Guard Dog [Beast] 13hp (2d8+4), AC 12, Spd 40’, Bite +4 (1d6+1); Stats 12.14.15.3.14.7; Perception proficiency, Keen Smell
  Riding Dog [Beast, Mount] 11hp (2d8+2), AC 12, Spd 40’, Bite +4 (1d6+2); Stats 15.14.12.3.12.7; Keen Smell
  Giant Eagle [Beast, Mount] 13hp (2d10+2), AC 13, Spd 10’/fly 60’, Talons +4 (2d4+2); Stats 14.17.13.8.14.10; Perception proficiency, Keen Sight
  Spinagon [Outsider, Fiend, Devil] 9hp (2d6+2), AC 11, Spd 20’/fly 40’; Fork +3 (1d6+1), Spines +3 (Rng 20’/80’, 1d4+1 piercing plus 1d6 fire, 12 spine/long rest); Stats 10.13.12.11.14.8; Darkvision 60’, Devil’s Sight, Fire Immunity, Cold & Necrotic Resistance, nonmagical/unsilvered weapon resistance, Innate Spellcasting (Cha) disguise self (DC 10, humanoid only), Infernal Telepathy

Tier 1 Elite

• Ogre [Giant] 48hp (5d12+15), AC 11 (hide), Spd 30’, Greatclub +7 (1d8+4), Javelin +2 (1d6+4, rng 30’/120’); Stats 19.8.16.5.7.7

Tier 2 Thugs

• Griffon [Beast, Mount] 33hp (5d8+10), AC 12, Spd 30'/fly 80', Claws +6 (2d6+3), Beak +6 (1d8+3); Stats 16.15.14.10.15.13; Keen Sight, Perception Proficiency
  Pegasus [Beast, Mount] 39hp (6d8+12), AC 12, Spd 60'/fly 90', Hooves +7 (2d4+4); Stats 18.15.15.10.15.13; Insight proficiency,
  Blink Dog [Beast] 28hp (5d8+5), AC 13, Spd 40’, Bite +6 (1d8+3); Stats 12.17.12.10.13.11; Teleport (40’, recharge 4-6), keen smell
  Bear [Beast, Mount] 60hp (7d8+32), AC 12, Spd 30', Claws +7 (2d4+4); Stats 18.15.19.10.15.13; Keen smell

Tier 3 Mooks

• Wight [Undead, Unliving] 15hp (6d4), AC 14 (Studded Leather), Longsword +5 (1d8+2 or 1d10+2 two-handed), Longbow +5 (1d8+2, Rng 150’/600’), Life Drain +5 (1d6+2 necrotic); Stats 13.14.10.10.13.15; Stealth Proficiency, Life Drain (any damage done by this attack also lowers the victim’s maximum HP by the same amount, the reduction lasting until they take a long rest, any creature slain by this attack rises as a zombie at the next sundown under the wight’s control to a maximum of 4 controlled zombies at a time); Condition Immunity to Fatigued, Exhaustion, & Poisoned; Immunity to Necrotic & Poison damage; Vulnerable to Radiant damage; Resistant to Nonmagical weapon damage that is not silvered, Darkvision

Tier 3 Thugs

• Unicorn [Fey, Celestial, Mount] 59hp (9d8+18), AC 15, Spd 50’; Hooves +8 (2d6+4), Magic Horn +8 (2d8+4); Stats 18.14.15.11.17.16; Trampling Charge (20’ + attack = +x2 dmg + Str DC 16 or knocked prone), Glamour Shield (Add Cha to AC, can grant same bonus to another target up to 60’ away until the start of its next turn as a bonus action), Cure Horn (3/day, neutralize disease & poison, heals 2d8+4), Insight proficiency, Resistant to Magic
  Drake [Dragon, Mount] 68hp (9d8+27), AC 16 (natural), Spd 40’/fly 80’; Bite +8 (1d10+4), 2 claws +8 (1d6+4); Stats: 19.10.16.5.12.6; Breath Weapon (Recharge 5+, 60’ line, 10d6), Perception proficiency, Blindsight 10’, Darkvision 60’

[Username17]

This is too detailed and doesn't have enough monsters for me to make head or tail of what you're trying to do. Like, what do you think it means to have 15 hit points? What does it mean for something to be Tier 2?

The projected groups of enemies are fucking enormous compared to what 5th edition rules or characters are capable of facing. So I don't know how or why this has the 5e tag on it. I seriously don't know what ruleset or assumptions I'm supposed to or even can judge these by.

-Username17

[virgil]

I am not sure how having 15hp is confusing and I thought the tag was clear that this is presuming everything is using D&D 5e rules, but with different monster stat blocks

Tiers and categories are a substitute for challenge rating, and tiers are clearly labeled with their intended groupings.

[Username17]

OK... but while it's a slight exaggeration to say that 4 PCs can't possibly defeat 16 enemies even if they were mosquitoes and garden slugs, it's not much of one. 5e rules are incredibly punishing when you are outnumbered. I'm really just not sure how four 1st level PCs are supposed to fight and win against 6 Spinagons let alone sixteen Lemures.

I understand that those are the kinds of numbers that Dungeons & Dragons should be dealing in, I just don't see how 5e can be a game that does it.

-Username17

[maglag]

OK... but while it's a slight exaggeration to say that 4 PCs can't possibly defeat 16 enemies even if they were mosquitoes and garden slugs, it's not much of one. 5e rules are incredibly punishing when you are outnumbered. I'm really just not sure how four 1st level PCs are supposed to fight and win against 6 Spinagons let alone sixteen Lemures.

I understand that those are the kinds of numbers that Dungeons & Dragons should be dealing in, I just don't see how 5e can be a game that does it.

-Username17

The lemures here only have 15 ft speed and only melee attacks, so they can be easily kited.

[Schleiermacher]

This is relevant to my interests.

But how do you determine monster HD type? You're using everything from d4 to d12, and it doesn't seem to be based on size, type, tier or encounter design role?

[virgil]

HD type is whatever generates the hit point range I want.

I do agree that it looks like the dretches & spinagons are too tough for level 1 players. From my math, however, I think four starting PCs could potentially take on 16 lemures. For the spinagons, I'd estimate it's more accurate for them to be a 1-for-1 deal. Ultimately, this means I either nerf the fiends more or include an addendum to the encounter design notes to use smaller monsters for the first two levels.

[Username17]

The lemures here only have 15 ft speed and only melee attacks, so they can be easily kited.

We're talking 5th edition characters. There's no easy or obvious way for characters to kite things.

16 enemies take up an enormous amount of the map. Every one of them can move and attack enemies 4 squares in any direction. From 16 starting points, that's pretty much the whole map. It's like claiming that because pawns in Chess are slow that you can go around them. Yes they are slow, but they cover the entire map so you can't go around them.

-Username17

[maglag]

The lemures here only have 15 ft speed and only melee attacks, so they can be easily kited.

We're talking 5th edition characters. There's no easy or obvious way for characters to kite things.

16 enemies take up an enormous amount of the map. Every one of them can move and attack enemies 4 squares in any direction. From 16 starting points, that's pretty much the whole map. It's like claiming that because pawns in Chess are slow that you can go around them. Yes they are slow, but they cover the entire map so you can't go around them.

-Username17

Throw javelin/shoot basic bow and move back 30 feet (basic movement speed), the lemures will never be able to catch up while being worn out. Even slower 20 feet characters can keep up just by double moving half the rounds then shoot+move the others.

And if the lemures spread out to maximize their coverage and somehow got to surround the party, their slow speed still means they can't properly close the encirclment fast enough. If the players pick their targets smartly, they can chop down the closer lemures first while the farthest ones can only slowly limp closer.

If the party can set up any sort of chokepoint (and they move faster than the lemures so unless there was some surprise gate they can just make a tactical retreat to better terrain) then the lemure numbers also mean a lot less as they can just line up and get killed one by one.

Either way it's virtually impossible for all 16 lemures to get their attacks off in the same round unless the party splits up and then runs straight to the middle of them.

[Username17]

Maglag, your featureless plain horse archer fantasies are probably not relevant to the sorts of encounters 5th edition characters are likely to have at 1st level.

The idea that there would be a meaningful "middle" you could run through that was more than 8 squares wide is patently ridiculous. Most encounter areas don't even have 10 squares for there to be an 8 square space between two Lemures in with worst possible placement.

-Username17

[Chamomile]

A quick glance at some of the dungeons I've assembled with Gabriel Pickard's map packs (and being that he is one of the most prolific map designers on Roll20, I'm reasonably certain he's a fairly representative sample of how people are making their dungeons - definitely the ones in Hoard of the Dragon Queen didn't tend towards significantly bigger rooms) suggests that 10 squares across is indeed a pretty typical dungeon room size - the long way. Often the skinny bits are no more than 4 or 5 squares across, which would allow even a single lemure to command a chokepoint. If that chokepoint is just around a character, the lemure can only be kited if it's sporting enough to chase characters around the corner. In fact, sixteen is well past the point where it would be difficult for the lemures to even bring all their forces to bear on the party at once in a standard dungeon room. Not corridor, room.

In field battles, of course, there is presumably always more room to back up unless an unhelpful terrain feature gets in the way, but probably encounters should work in the environment type the game is named after.

[maglag]

Maglag, your featureless plain horse archer fantasies are probably not relevant to the sorts of encounters 5th edition characters are likely to have at 1st level.

The idea that there would be a meaningful "middle" you could run through that was more than 8 squares wide is patently ridiculous. Most encounter areas don't even have 10 squares for there to be an 8 square space between two Lemures in with worst possible placement.

-Username17

Frank, you're the one who was always claiming that horse archers dominate everything in the 5e monster manual.

But there's no horses here in either side.

And if you're now claiming there's no featurless plains, then again there will be chokepoints like I mentioned. Thus unless the party positions themselves horribly, the 16 lemures will never be able to get a proper surround and the players can engage them only a few of them at a time.

Open plains or cramped dungeons, the party can out-maneuver the lemures unless there's some dickish trap mixed in that literally drops the 16 lemures all adjacent to the party turn 1. It's as simple as that.

[deaddmwalking]

It's totally not crazy to think that there will be times that the party will end up in a non-optimal position where further retreat is impossible. If the party ends up backing up to a locked gate, for instance, they may not have time to break it down before they are surrounded and overwhelmed.

If lemures typically exist because they are summoned, that also might impede the ability to kite the opponent in a meaningful way.

Regardless, the 'tiers' don't work. There's a really big difference between 1st and 2nd level characters; treating an encounter the same for a 1st level party and a 4th level party.

Two ogres against a 1st level party is at least as bad as 16 lemures. They certainly wouldn't be able to outrun a group of six Spinagons. With the relatively low hit point totals of Spinagons, maybe they'd be alright some of the time, but no matter what, the tiers don't work. Treating a 1st level party and a 4th level party the same is broken on first principles.

[virgil]

Already acknowledged. Though, really, this is essentially the case for all prior editions to treat the first level or two differently from the rest when it comes to capability.

[Username17]

Frank, you're the one who was always claiming that horse archers dominate everything in the 5e monster manual.

But there's no horses here in either side.

And if you're now claiming there's no featurless plains, then again there will be chokepoints like I mentioned. Thus unless the party positions themselves horribly, the 16 lemures will never be able to get a proper surround and the players can engage them only a few of them at a time.

Are you honestly telling me that you are incapable of understanding that the adventure "Kaiju menaces city" is on a different scale from the adventure "The mayor's daughter has been kidnapped by an infernalist cult"? Because the expected battlefield sizes of those two showdowns are really different. One of them takes place "at the harbor" and the other one takes place "in the basement." So spreading out and shooting arrows from long range is an obvious tactic in the first one and is not remotely feasible in the second.

Which means that it can be a problem that the Kraken can't survive a mild kiting and it be a problem that Lemures will curb stomp the player characters if they don't kite them to pieces. Both of those can be problems for the game, because the expected encounter spaces are very different. And if you pretend to not understand that for one more post I'm going to stop talking to you.

A typical 1st level player character in 5th edition D&D has about 10 hit points and an AC of 15. They will go down after being attacked about 15 times by those Lemures. They have essentially no ability to crowd control enemies with 7 hit points, and don't even drop a Lemure every attack. Even if you had a reasonably decent choke point, it's still extremely likely that you're going to lose half the party before chewing your way through a Lemure wave. And if you don't have a choke point you're probably looking at a party wipe in about 6 turns.

-Username17

[DrPraetor]

Taking the standard adventuring party of a Human Paladin (in heavy armor), a Halfling Rogue, an Elf Wizard and a Human Cleric, I present:

an example of play:

http://www.enworld.org/forum/showthread ... in-the-DMG

DM: There are a group of over a dozen lemures just around the corner, 20 ft. away from you.
everyone rolls initiative

Tripod Tim: I run away. Sorry, I dash.
DM: That's 60 ft. between you and the lemures.
Lethhonel Phirieth: I have my sling out?
DM: Sure.
LP: I also dash.
DM: That's 90 ft.
Stram the Pious: I dash away as well. I have my crossbow out?
DM: Crossbow out, yes. You're wearing studded leather, right?
StP: Yeah, all I can afford.
DM: Then you go 90 ft. as well.
Stram the Bold: I'm wearing full chain, so I only dash 60 ft?
DM: Correct. The lemures also dash, so that's 60 ft.

repeats for another round.
TT: I dash for a third time.
DM nods, makes a note.
LP: Okay, I've got more than 60 ft. between me and the lemures now, correct?
DM: You do.
LP: I fire a sling stone.
Rolls a 16.
DM: You hit.
Rolls a 2..
DM: It's still up.
StP: I load and fire a crossbow bolt.
Rolls a 5.
DM: It clatters into the darkness.
StB: I dash another 60 ft.
DM: And the lemures dash another 60 ft. Next round.

TT: I dash for a fourth time.
DM: Your Con mod is +0?
TT: Yeah.
DM: You have to make a Con check to avoid a level of exhaustion, since you've dashed more than 3 times.
TT rolls a 13
DM: Good so far.
And this repeats for a while...

StB: And I dash again...
StB rolls a 3.
DM: That's 2 levels of exhaustion. Your speed is now halved.
StB: How many lemures are left?
DM: 15.
StB: Okay, I'll charge the lemures instead. I yell "run and save yourselves!" as I do.
DM: Ooh, 50 bonus XP for roleplaying in combat.
StB: Can I have it on my next character?
DM: Sure.
DM: Five of the lemures charge Stram the Bold, the other 11 charge around on each side of him.
Rolls a bunch of dice for attacks and so forth.

Another round or so...
TT: Okay, I'm going to try and hide just by falling prone and huddling under my cloak.
DM: Uh... go ahead and roll a Dex (Stealth) check?
Tripod Tim rolls a 3.
DM: Tim's prone body does count as an obstacle.
DM rolls a 5.
DM: You've got enough distance between yourselves and the Lemures that you can roll to escape them.
LP rolls a 15, StP rolls a 13.
DM: That'll do. Now, roll will saves, to pretend you can't hear the noises.
LP rolls a 4, StP rolls an 11.
DM: Gesturing at LP. It's a wet sound, but very distinctive, almost high pitched, like a kind of bell - the sound of a child - or a halfling's - body - striking the stone repeatedly.
StP: He was basically a Kender anyway, so I'm glad he's dead.
DM: Nods approvingly. That's worth 50 bonus XP, no question.

[virgil]

Against lemures, let's take a standard adventuring party of a human fighter, high elf wizard, halfling rogue, & human cleric, only this time, they stand and fight rather than spend the entire time running...
[*] the cleric is literally invulnerable to a standard attack. It will take eight lemures surrounding him and wailing for a minute before enough crits go through to take him out - unless he casts protection from evil and good or heals himself or actually fights back (taking out one every round or two)
[*] the fighter is only hit 1 in 5 times, and it requires 10+ successful attacks to go down, while his own attacks are "check for natural 1" and take out a lemure on either one or two hits (about 50/50). This guy can plausibly solo half a dozen
[*] the rogue, who is absolutely adjacent to the fighter, is absolutely taking out a lemure per round while needing to be attacked 12+ times to go down himself. I can believe this rogue taking out four lemures
[*] the wizard also needs to be hit 12+ times to go down, and whatever he takes out will be pretty contextual, but even at his absolute worst he can likely solo three of them with just his sword and mage armor

I don't know how many this party can actually take out, but sixteen isn't unbelievable. Not that I didn't take the input and adjust the first two levels for encounter estimation anyway.

[Username17]

Yes. If you are literally exactly a human who takes the bonus feat and then spends their domain on heavy armor proficiency and then spends their feat on heavy armor mastery then you will specifically have the ability to survive against a horde of extremely shitty mooks. Your character won't be good, and it won't be able to really do anything else. And honestlythe fact that you about 19 attacks to get rid of all the Lemures with your maul means that you're going to get crit fished a fucking huge amount of times and may have to spend some spell slots on healing. But fortunately you do have that.

Now, 3 points of Damage Reduction is actually complete garbage in virtually any other scenario. The Ogre goes from knocking you down in two hits or one crit to knocking you down in two hits or one crit. That's a fucking huge amount of personal resources to spend on winning this one encounter. It does work, but I find it instructive that you skipped over the first listed Cleric on the sample characters list to get the one character who managed to permanently cripple their character for the supreme power of being essentially invulnerable to extremely weak attacks that are only supposed to matter at 1st level.

This is of course a fundamental issue with 5e characters. Only Humans even fucking get a feat, and Clerics don't even qualify for the feat in question unless they select specific domains. Without that, you just sort of crumple and collapse. There are no crowd control abilities. And most characters don't even have selectable abilities worth noting. An Elf Rogue doesn't have feats or domains. They just are. And what they are is something that can stand for like 3 rounds while getting shredded by bullshit monsters that the players aren't supposed to respect or care about.

5e is a fucking awful game. And the general lack of ability of almost all player characters to do basically anything about groups of enemies is a big reason why.

-Username17

[maglag]

Frank, the core rules allow to swap stat increases for feats.

And in a land where groups of low level enemies remain a viable threat, a feat to make them that much less of a threat sounds like a pretty sweet deal to me. Yes, big bruisers won't care, but few feats are useful against every opponent. The Kaiju will bring his spawn along, the ogre will have his goblin underlings.

Also notice that lemures are mindless, and if you're fighting in some dungeon then even in 3e the classic 1st level crowd control spells of entangle/color spray/sleep are all worthless against them.

[Whiysper]

The core rules allow to swap stat increases for feats.

Not really relevant until level 4, though - so talking about this in the context of level 1 characters is kinda daft. Nothing else useful to contribute at this stage, but will keep an eye out and shout if anything leaps out .

[Chamomile]

Also worth noting that only a tiny minority of builds will ever want anything but stat increases until level 12, and some until level 19. Feats exist in 5e, but outside of some kind of "pick a feat in addition to a stat boost" house rule, you mostly don't want them.

[maglag]

The core rules allow to swap stat increases for feats.

Not really relevant until level 4, though - so talking about this in the context of level 1 characters is kinda daft.

By the OP's standards, what monsters the party faces depends on their tier and level 4 is still the first tier.

[deaddmwalking]

The core rules allow to swap stat increases for feats.

Not really relevant until level 4, though - so talking about this in the context of level 1 characters is kinda daft.

By the OP's standards, what monsters the party faces depends on their tier and level 4 is still the first tier.

Except he also specifically retracted that, indicating that Tier 1 needs to be divided between Level 1-2 and level 3-4 at the very least.

[virgil]

but I find it instructive that you skipped over the first listed Cleric on the sample characters list

FYI. I literally did not notice the first cleric. The characters I grabbed were both the first ones I noticed (within my personal restriction of fighter-wizard-rogue-cleric) and the only ones I downloaded.

5e is a fucking awful game.

So? It's still the biggest game in town.

And the general lack of ability of almost all player characters to do basically anything about groups of enemies is a big reason why.

I mean, do you want me to dig through the pregen list some more to find a party that can't handle sixteen lemures, even after acknowledging the limits of the first level or two to halve that number?

Addendum: Let's look at the first cleric (at level 1) instead, if that will make you happy (hint: it likely won't)
[*] the dwarf cleric can plausibly solo five lemures (four if we're cautious), more if he casts any spells

[DrPraetor]

Actually, I think the second cleric is about the right power level for a 1st level character, so D&D 5th edition is better than I would've expected in that respect. The real problem is not that his power is useless against an Ogre, but that it becomes useless as the game progresses (as damage gets bigger and/or becomes all magic.) With that caveat, someone made a cool pirate cleric using these rules, and my hat is off to them.

Other than that cleric - who is indeed immune - Virgil may be ignoring some important math for the 16 lemures (12 attacks is not very many, Virgil), but he dropped it to 8 and I don't care because that isn't the problem. The problem is that 5th edition is full of null-pointers that lead to segmentation faults when you play.

I'm not saying the fix is easy. Good design for a lot of these questions is hard, but even bad design is generally better than no design.

Let's take an example that is stumping me on the other monster-manual writing thread, which is the doppelganger. Well, you want the doppelganger to interact with stealth and disguise etc. rules which, furthermore, you want to be good rules. So I'm stopping on that while I think about how those systems ought to be structured; finishing something like that would be intimidating anyway but stopping points such as that are going to be a big source of delay given I'm mostly thinking about other hard problems with higher stakes than doing a good set of heartbreaker house rules.

You can't write a good monster manual for the 5th edition of D&D because those rules, which you need to support various important monsters, don't even exist. This is an even worse problem than the failures in character concept aging, the balance deficiencies in the customization options, the inconsistent scaling of various potential crowd-control options, and so on.

Virgil's other core assertion is that 5th edition is the most popular thing out there so you want to try and cram material into it, and I don't think that's true either. 5th edition is doing really badly.