ECL vs. CR (WizO, sticky please?) [Archive] - Wizards Community

Post/Author/DateTimePost
Reyemile

04-16-07, 09:59 PM
After seeing the twentieth thread on CR vs. LA in two months, I really think that it's time for this board to have a sticky on the topic.

CR: Challenge Rating (CR) rates the difficulty of a monster as an encounter. In other words, a CR 4 monster should use up about 1/5 of the resourses of a party of four 4th level adventurers. CR measures the monsters' capabilities in a single fight; it also presupposes that the monsters are NPCs, with listed equipment and stats.

CR also factors in weaknesses that NPCs aren't expected to be able to overcome; Ogres, for instance, have no ranged attacks, so if adventurers can get the drop on them with bows or spells from a distance, they drop fairly quickly. Contrast this with an Ogre PC, who might have a spellcaster ally to teleport him or Boots of Striding and Springing to close the gap faster.


ECL: Effective Character Level (ECL) is the level of adventurer that a given monster is equivalent to. In other words, an ECL 16 Erinyes is considered an appropriate member of a level 16 party. ECL presupposes that the monster's stat mods are applied to normal stats (i.e. point buy or 4d6), and that the PC playing the monster has access to the same magic items as a regular PC of her level.

ECL is a combination of the monster's Hit Dice and its Level Adjustment. Level Adjustments (LA) are phantom levels to balance a monster's capabilities with that of normal PCs. The above Erinyes has several powerful abilities, including permanent True Seeing and Greater Teleport at will. If a 9 HD Erinyes were to be put into a party with regular 9th level PCs, she would steal the show. Thus, she has an LA of +7, which is added to her 9 Hit Dice to get her ECL of 16.


ECL and CR are not the same, nor should they be: Many abilities are substantially more powerful on PCs than on NPCs. For instance, since most encounters last ten or fewer rounds, Fast Healing 3 on a monster is roughly equivalent to an extra 30 hit points. This obviously makes the monster more of a threat, but it doesn't represent a huge jump in power.

On a PC, however, Fast Healing 3 means that the player's party will never have to spend a healing potion on him, and that he will be at full hit points at the beginning of every encounter; if he is ever dropped, he automatically stabilizes, and if he is concerned for his life he can fall back behind his allies until he is fighting fit. Fast Healing 3 is much more effective on a PC than on a monster.

Another example is DR x/Magic. By eighth or ninth level, nearly every PC will have some form of magic weapon, making the trait a non-issue in terms of CR. However, most Elementals, Undead, Plants, Animals, and Magical Beasts are incapable of penetrating Magic DR. On a PC, DR/Magic is very strong.

There is no formula to calculate ECL from CR: Consider, for instance, a monster with +8 natural armor versus a monster always found in Full Plate.

As an encounter, they both have exactly the same AC. From the perspective of their threat, where they get their AC from does not make a difference in the difficulty for a party to defeat them.

However, as PCs, the former monster can purchase a suit of Full Plate that stacks with it's natural armor, for a total AC of 26. The latter, however, wouldn't even begin with a suit of full plate unless its player decided to purchase one. If the second monster's player wants to stack the armor modifiers higher, he has to deal with the geometrically increasing costs of magic items.

Thus, two monsters whose defensive capabilities are identical when taken out of the book end up with vastly different power levels when made into PCs; the same CR can have different ECLs.

Another example is any spell-like ability usable 3/day versus the same ability at-will. In a single encounter, a monster will rarely use the same spell-like abilities more than 3 times, so it makes a minimal difference in how threatening the creature is. In the hand of a PC, however, the power gap between 3/day and at-will should be self evident.

If there is a correct LA for most monsters, this board can't agree on it: The ECL/LA system has many detractors, and it is hard to apply consistently. One of the biggest problems with judging a fair ECLs for monsters is the "glass cannon" phenomenon. Some monsters, such as the permanently invisible pixie, have tremendously powerful magical abilities, even with their Level Adjustment factored in. However, their high LA means they have very few Hit Dice, leaving their hit points (and saves) low. They therefore tend to be crippled or killed by spells that are mere inconveniences to the rest of their parties.

Spellcasting is another problem--even an LA of 2 or 3 can make a race with spellcasting capablities sub-optimal, because caster levels are so important. Balancing Sylphs, Araneas, and Unbodied (which all have innate caster levels that can be increased through future class levels) is tricky business.

Finally, there is the "plot breaker" problem. The above Erinyes can us her Teleportation and True Sight to bypass a number of story obstacles. If the characters need to get an item from the vault of an evil church, she can teleport in and teleport out without having to give up offensive spell-slots. If the PCs are supposed to hold out against a demonic invasion until word reaches the proper authorities, she can instead teleport directly to the Archmagus' tower and ask him to help immediately. If the king has been replaced with a disguised Drow, her true seeing will automatically reveal him--the party Mage with True Seeing might not think to bother using a spell slot for it while in town, but the Erinyes doesn't need to spend any resources. Her ECL of 16 is at least partially intended to balance her effects on the DM's plot. However, this adds several levels of LA to pay for abilities that are only tangentially related to combat. As a result, she may find herself under-performing in encounters tailored to the level of the rest of her party.

Searching this forum will reveal a thread on the balance of practically every monster in the book, but the best bet is to simply try the monsters out yourself and to be prepared to make adjustments on the fly to keep the party balanced.
runestar

04-16-07, 10:32 PM
One way of circumventing the problem of glass cannons is simply to not play the race unless you are in a higher lv campaign. A pixie is quite fragile in a 5th lv game(since he has just 1 HD, even with dr/sr/invis). In a lv10+ game, he will have 6+ HD, enough hp to withstand a hit or 2.

I agree with the concept of LA/ECL, even as I admit that not all LAs assigned are necessarily accurate. But this is a flaw with the calculation process, not with the design aspect of LA. :)
Crimson_Concerto

04-16-07, 10:47 PM
I'm going to agree that something to this effect DEFINITELY needs to be stated, and this thread might as well be it. I support your cause. :)
Jaxgaret

04-16-07, 11:46 PM
I'm going to agree that something to this effect DEFINITELY needs to be stated, and this thread might as well be it. I support your cause. :)

Seconded.

The OP of this thread is as good a post to sticky as any I've seen.

Kudos.
Reyemile

04-17-07, 12:18 AM
Seconded.

The OP of this thread is as good a post to sticky as any I've seen.

Kudos.Awww, shucks :blush: :blush:
Squirrelloid

04-17-07, 12:41 AM
I'd like a more neutral tone with regards to specific monsters. Saying an Erinyes is actually an ECL 16 monster outright is really funny. The thing about fast healing 3 is also really funny, actually. A post that wrote it from a neutral perspective ('this is how the designers felt' rather than 'this is the way it is objectively') would be far better. Because this is really an instance of what the rules say, not what will lead to balance or fun at the table, and thus a blatant endorsement isn't necessarily acceptable.
Reyemile

04-17-07, 01:17 AM
I'd like a more neutral tone with regards to specific monsters. Saying an Erinyes is actually an ECL 16 monster outright is really funny.
I'm not saying that an Erinyes is an ECL 16 monster--I'm saying that an ECL of 16 means a monster is equivalent to a 16th level character, which is, in fact, the definition of ECL. I know that people disagree on the ECL values for many races; there is a reason that I included a section to that effect at the end of my post. The thing about fast healing 3 is also really funny, actually. A post that wrote it from a neutral perspective ('this is how the designers felt' rather than 'this is the way it is objectively') would be far better.How, exactly is this 'funny'? For a monster, 30 HP and Fast Healing 3 are roughly equivalent--for a PC, the latter is way more valuable than the former. I am not endorsing a specific LA value for Fast Healing, or anything--all that I'm saying is that abilities need to be viewed very differently for monsters and for PCs. Do you disagree with that? If so, why? Just saying that I'm "funny" is not helpful at all.

Also, please don't post alternatives to the ECL system in this thread. The point is to have an explanation of terms and concepts to sticky for new and inexperienced players. If they need this thread to get a primer on the basics, then they probably don't have the experience to evaluate any houserules you suggest. The RAW may not be perfect, but it's still the RAW. If you have suggestions about the contents of my OP, make them, but take the tangents to another thread, please.
Squirrelloid

04-17-07, 01:23 AM
I'm not saying that an Erinyes is an ECL 16 monster--I'm saying that an ECL of 16 means a monster is equivalent to a 16th level character, which is, in fact, the definition of ECL. I know that people disagree on the ECL values for many races; there is a reason that I included a section to that effect at the end of my post. How, exactly is this 'funny'? For a monster, 30 HP and Fast Healing 3 are roughly equivalent--for a PC, the latter is way more valuable than the former. I am not endorsing a specific LA value for Fast Healing, or anything--all that I'm saying is that abilities need to be viewed very differently for monsters and for PCs. Do you disagree with that? If so, why? Just saying that I'm "funny" is not helpful at all.

Well, by your own logic, combat lasts < 10 rounds, so its actually < 30hp. Further, its really not the duration of combat that matters, but the duration of the monster in combat from the first hit it takes to the last. Fast Healing 3 is worth maybe 6 hp before the monster goes down, if its lucky.

(I just ran 2 Cave Trolls (CR 8, EL10) against my level 6 players. Combat lasted 2 rounds total, and their Fast Healing 8 was totally useless).


Also, please don't post alternatives to the ECL system in this thread. The point is to have an explanation of terms and concepts to sticky for new and inexperienced players. If they need this thread to get a primer on the basics, then they probably don't have the experience to evaluate any houserules you suggest. The RAW may not be perfect, but it's still the RAW. If you have suggestions about the contents of my OP, make them, but take the tangents to another thread, please.

If you insist I can edit it out. I was just in game-design mode.
Reyemile

04-17-07, 01:35 AM
Well, by your own logic, combat lasts < 10 rounds, so its actually < 30hp. Further, its really not the duration of combat that matters, but the duration of the monster in combat from the first hit it takes to the last. Fast Healing 3 is worth maybe 6 hp before the monster goes down, if its lucky.

(I just ran 2 Cave Trolls (CR 8, EL10) against my level 6 players. Combat lasted 2 rounds total, and their Fast Healing 8 was totally useless).So basically, what you're saying is that you agree with me, that short encounters make Fast Healing an item/spell saver for PCs but minimally effective on monsters. Not sure why you felt the need to say that my post was "funny," but I'm glad we're on the same page.

If you insist I can edit it out. I was just in game-design mode.I don't think you really need to, just please refrain in the future. I don't want this thread to degenerate into a flamewar over whose houserules are best.
Squirrelloid

04-17-07, 01:51 AM
So basically, what you're saying is that you agree with me, that short encounters make Fast Healing an item/spell saver for PCs but minimally effective on monsters. Not sure why you felt the need to say that my post was "funny," but I'm glad we're on the same page.


Not exactly - players achieve the same thing for characters without fast healing by giving them fast healing (Lessor Vigor, via wand, at ~1gp/hp, is dirt cheap healing). Basically, no one should ever go into combat at anything other than fully healed. Fast Healing is 'save a miniscule amount of gp' as an ability.
Radijs

04-17-07, 03:25 AM
This thread is going in my sig. Everybody else, do the same.
Reyemile

04-17-07, 03:17 PM
I added a little bit more about the Erinyes. She probably is not as effective as she could be in combat at level 16, but I'm not 100% sure that that invalidates her ECL; see my post for why.

Remember, though, this is a conceptual thread; if you disagree with the concept that I'm illustrating, fine, but if you want to argue over the exact numbers please keep it in confined to the Erinyes thread.
InsanePsychoRabbit

04-17-07, 04:18 PM
This is an excellent treatise, and people ask this question all the time in multitudes of topics. If this isn't stickied....I just won't be happy.
Fiddletink

04-18-07, 01:12 AM
check what the CR is on a lvl 8 Fighter, Human... wow a CR 8, now how is it again that CR is not supposed to be tied to ECL?
HappyGhoul

04-18-07, 01:29 AM
check what the CR is on a lvl 8 Fighter, Human... wow a CR 8, now how is it again that CR is not supposed to be tied to ECL?

1. Read
2. Comprehend
3. Reply

Do not skip to step 3. Reyemile's entire OP explained exactly this. I see no way you could have read and understood it and still have this question.
JLaurHughes

04-18-07, 02:06 AM
check what the CR is on a lvl 8 Fighter, Human... wow a CR 8, now how is it again that CR is not supposed to be tied to ECL?

To clarify what is meant by the OP, I hope. CR 8 humans(8 HD) don't have any special racial abilities, whereas a CR 8(ECL X) Monster might have special abilities which essentially add +1 for each powerful special ability that the monster has or special ability combo. Ex: Fast healing is a relatively powerful ability during combat, especially when coupled with DR X/Magic where X = how much damage from weapons that don't meet the requirement gets negated...in this case any non magic(masterwork or lower) weapon. Effectively if your Barbarian with his d12 weapon and his strength 18 doesn't have that +1 Magic enhancement, average is 6.5+1.5xStr with Str mod of +4 this is about 12-13 damage per swing on average with the mentioned weapon damage. Effectively negated or reduced with that mentioned combo. This is worth at least an ECL of +1 or LA of +1. I don't use a specific monster in my example for a very good reason, I can't be respectful with exact monster examples.

To the OP, I thank you for this thread, and support in the cause for which you want this stickied here. I hope my explanation is helpful to your cause and not the opposite.
Reyemile

04-18-07, 11:06 AM
I had a lot of trouble parsing the above post (please, proofread and paragraph!), but I think I get the gist of the question.

Let's imagine the Fighter Joe, an NPC with NPC equipment and the Elite Array, and Slimeball X, the hideous demon from the lower planes, have the same AC, Hit Points, and Damage. Slimeball X's special abilities are roughly equivalent in effectiveness to the fighter's bonus feats. Thus, the two of them, as encounters, are pretty much identical--their CRs should be the same.

But now, let's make them PC's.

Fighter Joe's stats barely change; if the GM is giving out a 32 point buy, Joe can bump his strength from a base of 15 to 17 and still have a few points to boost his Will Save. Slimeball X, however, can use those 32 points to give himself +6 to Strength and Constitution, since he started with all his stats at ten. If his stat mods are high enough that he is willing to take a -2 hit to his other stats, he can even set his base Str and Con to 18 for +8.

Fighter Joe's AC and Damage improve slightly; he gets about 50% more gold, so he can add an extra +1 to his sword and bump his half-plate up to full plate. Slimeball X's AC shoots through the roof, since a +1 chain shirt and a large shield both stack with the Natural Armor bonus he relied on as a monster. his damage, too, increases drastically as he upgrades from a 1d8+Str slam to a 2d6+(1.5*Str) greatsword.

Fighter Joe and Slimeball X still have the same amount of hit points; Joe's three extra Hit Dice make up for X's racial +8 to Con. This won't last, though; every level, X will gain four hit points (or more! X can afford to sell down wisdom for con) above what Joe gets, ensuring a slow but steady gain.

This is why two encounters with identical CRs can have a radical differential of effectiveness as a PC.
runestar

04-18-07, 09:23 PM
Oddly, enough, while the OP's exact same points are done to death in the FAQ, no one ever seems to care, notice or give a darn, and he has to specifically point it out before people actually start sitting up and taking notice.:(

Still, I believe it is a start in the right direction. Note that he is only stating that there is no necessary correlation between cr and ECL, not that all monsters' ECLs are balanced. So don't go faulting him when you start finding unfair ECLs.:)
Reyemile

04-19-07, 10:19 PM
:bump:
Pole4life

08-03-07, 09:09 AM
:bump:
Ecalsneerg

08-03-07, 09:13 AM
Excellent thread, should make it clear to some people.
Reyemile

08-03-07, 01:10 PM
Thanks. I just edited it to make it a little more clear and remove some niggling typos.
Onikani

08-03-07, 03:55 PM
count me for voting for the sticky!!!!

Clear and well written.
:cookie:
sigma999

08-03-07, 06:49 PM
Sticky! Well written, easy to understand.

True, CR is indeed by whim of the designer, usually for worse. Monsters are slapped together and 'eyed up'. It's a marginal improvement up from AD&D with its single XP value for every "kill".
When will WOTC learn????

Every character and NPC should be compared to each other on a 1v1 basis. No class or monster should be left behind in capabilities of a 1v1 fight!
Then when you assemble any group of such balanced characters, accidentalTotal Party Kills and 'rocket tag' should be reduced dramatically as result.
Instead, CR is based on the assumption that a party has a well-equipped 4 person group of Wizard, Cleric, Fighter, and Rogue. DUMB.
Reyemile

08-06-07, 02:31 AM
Sticky! Well written, easy to understand.Thanks!
Every character and NPC should be compared to each other on a 1v1 basis. No class or monster should be left behind in capabilities of a 1v1 fight!
Then when you assemble any group of such balanced characters, accidentalTotal Party Kills and 'rocket tag' should be reduced dramatically as result.
Instead, CR is based on the assumption that a party has a well-equipped 4 person group of Wizard, Cleric, Fighter, and Rogue. DUMB.but it looks like it was hard to understand after all.

Take another look at the part where I describe campaign breakers. Is the Erinyes I use as my example were balanced according to a 1v1 fight, she would probably end up around ECL 12 or 13. But at ECL 12 or 13, she would absolutely dominate everything OUTSIDE combat in a way the rest of her party couldn't compete with, between her teleportation, true-sight, and charm person abilities.