Good monsters, bad monsters

[Kazyan]

So, there are some well-designed and memorable monsters in D&D 3.5. Then there are some that just work alright or are kind of neat, and no one complains about them in the "let's make fun of terrible monsters" threads. Sometimes there's a monster that keeps getting brought up because it's great for Polymorph, Shapechange, or other shenanigans. And then there are the bad design poster children/pinatas, e.g. Adamantine Horror.

In D&D 3.5, what makes a monster well-designed? What can make one awful? Is there an acceptable range of numbers for various statistics, beyond which the designer should be pointed and laughed at? What stuff doesn't quite work no matter how you twiddle the CR up or down? Discuss the difference between good monsters and bad monsters, I guess.

I'm gathering this information as a guide for homebrewing monsters. For a personal project, I'm making a whole bunch of them and don't want to make the same mistakes over and over. (If this should go in the homebrew design forum, I won't complain if the thread gets moved.)

[jiriku]

A monster should be well-tuned. It needs attacks and defenses that are appropriate for its challenge rating, lots of hit points, and a credible offensive capability.

The thing I hate most to see in a monster is a glass cannon: something with abnormally high stats, multiple extraordinary special attacks, and really low hit dice for its challenge rating. These kinds of monsters are really flukey in combat and don't consistently produce balanced fights, plus when emulated with polymorph they're broken, broken, broken.

[Vhaidara]

I can't name specifics, but in my experience
1. High damage output = bad
No one I've ever met likes getting rocket tagged. The more invested you are in the character, the more true this is

2. Disables = bad
This is partially a personal complaint, since I'm the only person in my usual groups who has had a character removed in the surprise round/before my turn. It happened three fights in a row, and two of them were lengthy fights, with one being half a session (approx 2 hours). But again, I don't think anyone enjoys being told "okay, you're out of this fight because you failed one save".
Note: Save or dies = really, really bad. It's disables + rocket tag

3. Debuffs = acceptable
Debuffs can be crippling, and they are the preferable means of debilitating someone, rather than straight up removing them. Even the most heavily debuffed fighter can still roll a 20 and turn a fight, or absorb some hits.

4. Large HP pools = good start
Rocket tag is a problem on both sides. It's hard to get a good fight when the individual PCs are able to one shot everything. Large groups of mooks are enjoyable for a while, but sometimes you want to throw something with a "Raid Boss" feel. Something that takes several turns to beat down

5. Other Damage mitigation = Good
Fast Healing, DR, SR, Regeneration. These are your friends, as long as they can be overcome by the group. No 3e style DR 50/+4 golems (I fought one of these. Screw. These. Things.)

6. Extra Actions
I've heard 4e did this with Elites and Boss monsters. This is a good thing if you're doing a solo encounter because, like it or not, action economy is an unpleasant woman. This should be balanced in with #4

7. Focus on not-killing = Very good
Maybe the monster prefers its meat fresh, so it captures and holds the party for later. Maybe it expects to be able to ransom them, or enjoys torturing people, or wants to turn them in for a bounty alive. Basically, don't kill them. Capture them. This can be a great mechanic for losing a fight without losing the characters. And non-lethal damage through attacks isn't the only way. Mix in disarms, trips, grapples, anything.

8. Summoning = Variable
Consistent summons are good, random summons are bad. Yes, I'm looking at you, succubus. Summoning above your own CR = VERY VERY BAD

9. Destruction of Equipment: Generally, very bad
These monsters are exclusively for when you, as the DM, realize you made a mistake with gear, and your players (or at least the player with the gear) agree.

[sideswipe]

I can't name specifics, but in my experience
1. High damage output = bad
No one I've ever met likes getting rocket tagged. The more invested you are in the character, the more true this is

2. Disables = bad
This is partially a personal complaint, since I'm the only person in my usual groups who has had a character removed in the surprise round/before my turn. It happened three fights in a row, and two of them were lengthy fights, with one being half a session (approx 2 hours). But again, I don't think anyone enjoys being told "okay, you're out of this fight because you failed one save".
Note: Save or dies = really, really bad. It's disables + rocket tag

3. Debuffs = acceptable
Debuffs can be crippling, and they are the preferable means of debilitating someone, rather than straight up removing them. Even the most heavily debuffed fighter can still roll a 20 and turn a fight, or absorb some hits.

4. Large HP pools = good start
Rocket tag is a problem on both sides. It's hard to get a good fight when the individual PCs are able to one shot everything. Large groups of mooks are enjoyable for a while, but sometimes you want to throw something with a "Raid Boss" feel. Something that takes several turns to beat down

5. Other Damage mitigation = Good
Fast Healing, DR, SR, Regeneration. These are your friends, as long as they can be overcome by the group. No 3e style DR 50/+4 golems (I fought one of these. Screw. These. Things.)

6. Extra Actions
I've heard 4e did this with Elites and Boss monsters. This is a good thing if you're doing a solo encounter because, like it or not, action economy is an unpleasant woman. This should be balanced in with #4

7. Focus on not-killing = Very good
Maybe the monster prefers its meat fresh, so it captures and holds the party for later. Maybe it expects to be able to ransom them, or enjoys torturing people, or wants to turn them in for a bounty alive. Basically, don't kill them. Capture them. This can be a great mechanic for losing a fight without losing the characters. And non-lethal damage through attacks isn't the only way. Mix in disarms, trips, grapples, anything.

8. Summoning = Variable
Consistent summons are good, random summons are bad. Yes, I'm looking at you, succubus. Summoning above your own CR = VERY VERY BAD

9. Destruction of Equipment: Generally, very bad
These monsters are exclusively for when you, as the DM, realize you made a mistake with gear, and your players (or at least the player with the gear) agree.

i agree with this in some way. but disabling a party member is not the mother of all evil. if your character has a flaw an enemy will come along who can exploit it, and that is why i play knowledge characters. so that we can learn about special abilities it may have (not ac or meta game stuff just "that ia a beholder! beware its gaze attack!" )

[kellbyb]

The thing I hate most to see in a monster is a glass cannon: something with abnormally high stats, multiple extraordinary special attacks, and really low hit dice for its challenge rating. These kinds of monsters are really flukey in combat and don't consistently produce balanced fights, plus when emulated with polymorph they're broken, broken, broken.

You know what's worse? An iron cannon. By this I mean a monster with, like in your example, abnormally high stats and multiple extraordinary special attacks, but with really high hit dice for the CR. Basically, something that can tank the party's damage while dishing out ridiculous amounts of damage on its own. That damn crab (http://www.wizards.com/default.asp?x=dnd/fw/20040221a) is a great example of this.

[gooddragon1]

I can't name specifics, but in my experience
1. High damage output = bad
No one I've ever met likes getting rocket tagged. The more invested you are in the character, the more true this is

2. Disables = bad
This is partially a personal complaint, since I'm the only person in my usual groups who has had a character removed in the surprise round/before my turn. It happened three fights in a row, and two of them were lengthy fights, with one being half a session (approx 2 hours). But again, I don't think anyone enjoys being told "okay, you're out of this fight because you failed one save".
Note: Save or dies = really, really bad. It's disables + rocket tag

3. Debuffs = acceptable
Debuffs can be crippling, and they are the preferable means of debilitating someone, rather than straight up removing them. Even the most heavily debuffed fighter can still roll a 20 and turn a fight, or absorb some hits.

4. Large HP pools = good start
Rocket tag is a problem on both sides. It's hard to get a good fight when the individual PCs are able to one shot everything. Large groups of mooks are enjoyable for a while, but sometimes you want to throw something with a "Raid Boss" feel. Something that takes several turns to beat down

5. Other Damage mitigation = Good
Fast Healing, DR, SR, Regeneration. These are your friends, as long as they can be overcome by the group. No 3e style DR 50/+4 golems (I fought one of these. Screw. These. Things.)

6. Extra Actions
I've heard 4e did this with Elites and Boss monsters. This is a good thing if you're doing a solo encounter because, like it or not, action economy is an unpleasant woman. This should be balanced in with #4

7. Focus on not-killing = Very good
Maybe the monster prefers its meat fresh, so it captures and holds the party for later. Maybe it expects to be able to ransom them, or enjoys torturing people, or wants to turn them in for a bounty alive. Basically, don't kill them. Capture them. This can be a great mechanic for losing a fight without losing the characters. And non-lethal damage through attacks isn't the only way. Mix in disarms, trips, grapples, anything.

8. Summoning = Variable
Consistent summons are good, random summons are bad. Yes, I'm looking at you, succubus. Summoning above your own CR = VERY VERY BAD

9. Destruction of Equipment: Generally, very bad
These monsters are exclusively for when you, as the DM, realize you made a mistake with gear, and your players (or at least the player with the gear) agree.

Oh this list. I love it so much. And agree with it.

[Segev]

Thinking on that list, Illithids are almost ideal. Their stun cone violates the "don't take us out of the fight" rule, but their brain-grabbing tentacles are perfect for the extended fight-for-your-life scenario. I think they have reasonable hp for their CR, too.

[Vhaidara]

i agree with this in some way. but disabling a party member is not the mother of all evil. if your character has a flaw an enemy will come along who can exploit it, and that is why i play knowledge characters. so that we can learn about special abilities it may have (not ac or meta game stuff just "that ia a beholder! beware its gaze attack!" )

Like I said, I have a personal vendetta there. And they can be acceptable, if used properly. But big fights shouldn't use them, especially not in the opening rounds, since those fights can drag on, and then you get someone sitting there bored for two hours because their character is paralyzed for 3 minutes.

Oh, that's another one. If disables are used, they should not exceed two or three rounds. A minute might as well be an hour (okay, not really, that bites into the next fight) in combat.

Oh, and ability drain/damage should not come in at a CR lower than lesser restoration becoming available. That stuff takes forever to heal without magic.

[Barstro]

You know what's worse? An iron cannon. That damn crab (http://www.wizards.com/default.asp?x=dnd/fw/20040221a) is a great example of this.

The crab isn't per se a bad monster. It's a decent monster that was given a very inappropriate CR. An iron cannon, as you put it, is simply a monster that needs better labeling.

To the left, HP and Attack aren't everything. A true iron cannon will be easily destroyed by a rust monster. My gripe is along the same line as glass and iron cannons; powerful monster that is easily defeated by some sort of trick. Results in either TPK or ridiculous xp, it's over in two rounds, either way.