Challenge Rating and Monster Manuals

[Greenfield]

We're in a 3.5 game, currently 2nd level.

The DM threw a dinosaur from MMIII at us, a CR2 creature.

My experience has been that the CR system, while questionable, is generally stable within any one version of the Monster Manual. The higher the MM version, however, the higher the actual power of the creatures at any given CR rating.

The Dinosaur in this instance is called a Fleshraker, a relative of the Velociraptor.

His attack sequence is 2 claws (+6 melee, D6+3 + poison), and a bite (+1 melee, D6 +1) and a tail slap (+1 melee, D6 +1 +poison). He can't use both the bite and tail slap on the same target. The poison is a DC 14 Fort save, D6 Dex/D6 Dex.

It has a Pounce attack that allows a charge, full attack, and an extra Rake attack (+2 melee, D6+2).

Improved Trip, which allows an immediate Grapple check. Success results in both Grapple and Pin. Target receives automatic claw and rake damage every subsequent round.

It's AC 20, 4 hit dice, and has 26 hit points.

It prefers to strike from ambush (+12 hide checks, +24 Jump checks), and a base move of 50.

To me, that looks a lot like a CR 4, maybe a 5.

It would eat a Black Bear (Monster Manual I, Page 269) for breakfast.

Black bear, also CR 2, AC 13, 3 HD 19 hp, attack 2 claws (+6 melee D4+4) plus Bite (+1 Melee D6+ 2). No poison, no Rake, no tail-slap, no trip, no free grapple. The bear would likely be gored on the 1st round and dead on the 2nd.

I'm not ranting about a monster though. I'm just asking if there is some semi-official guideline on CR adjustments for the different Monster Manuals.

My own rule of thumb seems to to take the listed CR, add the MM version, and subtract one.

Any help (other than the inevitable "The CR system is broken") is appreciated.

 

[Celebrim]

Be prepared to redo the CR of every thing in the books.

Tons of bad decisions were made, even in the early supplements. For example, they deliberately marked down the CR of dragons as 1-2 less than they knew them to actually be because they wanted dragons to be scary.

Check out the CR on the bigger elementals, most of whom can one shot characters of similar level with a full attack.

 

[Dandu]

Be prepared to redo the CR of every thing in the books.

Insofar as CR means anything - after all, a level 10 party consisting of a monk, paladin, healer, and warlock is going to perform very, very different compared to one composed of a warblade, cleric, druid, and wizard. There may honestly be too much variability in party composition and composition to make CR meaningful.

You're going to have to sit down, examine the monster, and do the math as to how it'd affect your party in the environment you choose to have the encounter in.

 

[delericho]

My experience has been that the CR system, while questionable, is generally stable within any one version of the Monster Manual. The higher the MM version, however, the higher the actual power of the creatures at any given CR rating.

Agreed.

I'm not ranting about a monster though. I'm just asking if there is some semi-official guideline on CR adjustments for the different Monster Manuals.

My own rule of thumb seems to to take the listed CR, add the MM version, and subtract one.

I'm not aware of any guideline. However, the one you suggest is probably not bad - though I'd probably cap it at MM3. I don't think 4 and 5 are significantly more powerful again.

(Oh, and don't forget to apply an adjustment for monsters in non-MM books - the monsters in the Eberron setting book are definitely more powerful than those in MM1!)

 

[Grogg of the North]

I've long thought that when the first monster manual was written the designers had the idea that the group consisted of a fighter (tanking), a cleric (healing the fighter), a rogue (flanking), and a wizard (lobbing AoE evocation magic). IIRC the monster manual stated when estimating CR of a monster that it should be pitted against a party consisting of those classes.

As the later books were written, I feel that the designers either gained more system mastery themselves or assumed a higher level of optimization was being used by players. While the party they considered fighting the monsters may still consisted of those classes they were definitely using different tactics. (Magic buffs, Touch AC is Your Save magic, Tripping, etc.)

Either way, CR is best used as a measuring stick. Before I drop a monster against the group I try to think quickly if the party will survive the fight or be a smear on the wall. I think we've all had that encounter. Where you sit there as DM and think "What the heck happened? This was only CR 6!" as the fighter gets eaten, the cleric is knocked out trying to save the fighter and the wizard high tails it back to town.

 

[Voadam]

3e's system always seemed a little backwards to me, starting with a base that seems based around HD (~1/2 HD?) then adjusting for added classes or HD or templates. It was fairly easy for adjusted creatures to be out of whack on their core numbers versus CR.

Pathfinder's monster creation systeml seems a decent guideline for estimating CRs based on their ending stats.

Spells and special abilities can be wild cards in CR though. Poison pounce should probably be an increase above the base HD with natural weapons.

At CR 4 or 5 26 hp looks really weak.

 

[Dandu]

I think we've all had that encounter. Where you sit there as DM and think "What the heck happened? This was only CR 6!" as the fighter gets eaten, the cleric is knocked out trying to save the fighter and the wizard high tails it back to town.

The answer, as always is insufficient optimization.

 

[delericho]

I've long thought that when the first monster manual was written the designers had the idea that the group consisted of a fighter (tanking), a cleric (healing the fighter), a rogue (flanking), and a wizard (lobbing AoE evocation magic). IIRC the monster manual stated when estimating CR of a monster that it should be pitted against a party consisting of those classes.

Yep. IIRC, they actually say as much in the 3.0e DMG.

As far as I can tell, they also assume that the Fighter doesn't have access to weapons that can bypass damage reduction, and that in cases of 'trick' monsters the party doesn't have the item to bypass the trick (eg Improved Sunder vs the Hydra).

As the later books were written, I feel that the designers either gained more system mastery themselves or assumed a higher level of optimization was being used by players.

This is also true. With the consequence that CR, which was always no more than a very rough guide, because progressively useless as the books progressed. (At least if they'd kept the CRs consistent, DMs could then apply a consistent correction for party optimisation. As it is, the DM has to correct both for party optimisation and a moving CR system. Or completely ignore CR and just eyeball encounters.)

 

[Greenfield]

The problem is about to be resolved.

The DM went straight back to MM III and threw 5 "CR2" opponents at our 5 person, level 1 and 2 party. Ww were in the middle of a TPK when we broke the game due to time considerations.

I could have my character run, but there's a poor chance of escape. Better to just let it end. We'll have to come up with a new campaign.

 

[Dandu]

Death resolves all problems!

Seriously, though, 5 CR2 enemies?