Factors Affecting CR and EL

[Erithtotl]

Levelled NPCs with poorly chosen equipment or abilities can dramatically alter effective CR.

Also, as a DM quickly chosing an opponent out of a published supplement, sometimes going by CR can have disasterous results, either for the party or for game balance.

I ran into a particularly vexing example when I needed a quick assassin statblock in Ptolus. I grabbed two of these guys. From page 140 (apologies to the otherwise exellent author of the DMG):

Typical Vai Assassin
Male or female human (Neutral Evil)
Rogue5/assassin2 CR 7
HD 5d6 + 2d6 hp 27
Init +2 Speed 30 feet
AC 15, touch 12, flat-footed 15
BAB/Grapple +4/+5
Attack/Full Attack +7 melee (1d4+2, dagger)
or +8 ranged (1d4+2, dagger)
SA Sneak attack +4d6, death attack (DC 14)
SQ Evasion, improved uncanny dodge, trap
sense +1, +1 saves versus poison
Fort +1, Ref +11, Will +5
Str 12, Dex 15, Con 11, Int 16, Wis 14, Cha 10
Crucial Skills: Balance +9, Bluff +8, Climb +9,
Disable Device +6, Escape Artist +12, Hide
+12, Intimidate +8, Jump +7, Listen +10,
Move Silently +12, Spot +8.
Other Skills: Disguise +12, Forgery +8,
Knowledge (local) +6, Open Lock +14.
Crucial Feats: N/A.
Other Feats: Deceitful, Iron Will, Lightning
Reflexes, Weapon Focus (dagger).
Spells: 2; save DC 13 + spell level.
1st—disguise self, true strike.
Possessions: Masterwork studded leather
armor, +1 dagger, masterwork daggers (3),
scroll of sleep, Large scorpion venom
(4 doses), dark reaver poison (1 dose),
50 feet of silk rope, climber’s kit, disguise
kit, masterwork thieves’ tools, 25 gp.

So here we have a 30 point buy, CR 7 opponent with a 15 AC, 27 hp, and 1d4+2 dmg per hit. You can argue that under the right circumstances, against an unwary opponent, this guy could be very deadly. But you can argue that for almost any opponent. A 1st level halfling rogue can kill you in your sleep just as easily as this guy. In other certain circumstances, a well chosen target for the deat attack and a bad save roll, or well targeted poison, could kill or cripple a PC with ease. But the character is so poorly optimized, and unncessarily so, that it fights way below it's CR.

He has no 'escape mechanism' (no tumble, no mobility, no invisibility potion, nothing), so if the initial attack fails he has no way of getting away. Of his approximately 4600gp in equipment, a whopping 3300gp is taken up in daggers, and 1100gp in poison, most of which he'll never use. Is that +1 to hit on the three throwing daggers really worth 900gp? How about investing the cost of ONE of those daggers in a potion of shield of faith (50gp), a scroll of invisibility (150gp), and two potions of Cure Light (50gpx2)? He has LIGHTNING REFLEXES. What, +9 reflex save just wasn't enough? 10 ranks in Escape Artist but not 1 in tumble?


Glancing at the monster manual, here are some other CR 7 opponents.
Aboleth
Bulette
Chaos Beast
Chimera
Chuul
Succubus
Hellcat
Dire Bear

Aboleth, seriously! This was against a party of 5th level characters. The character on guard duty made his listen check, and wiped the floor with them in short order. Imagine if I'd taken two aboleths against them. Or two bulettes!

 

[MerricB]

Merric, what about the Orb of Force?

ARRGGHHH!!!!

It's a rock.

Except it's a rock that affects ghosts.

It's a rock that affects incorporeal creatures as well, as far as I can tell. Maybe it conjures some meteoric rock or black hole material. I don't know.

ARRGGHHH!!!

 

[Blue]

This really hits home. I play in one game with very high stats and very high wealth with a 6 PC party. And I mean both of those VERYs. The DM keeps throwing high EL encounters at us to challenge us (and they're loads of fun!), but then has problems because everyone levels so fast.

He's put in place training rules that are designed to eat up weeks of time, including the ability to train in advance for levels so if you have the spare time and gold you won't get caught unable to advance mid-adventure.

But it really is case of exactly what you mention - PCs are a higher effective level because of multiple factors, and when you challenge them appropriately but then reward them at their "real" character level they get loads of XP.

Cheers,
=Blue(23)

 

[Phlebas]

2. Challenge-specific PC effectiveness. Some PCs will have an easier time defeating specific challenges, e.g. a ranger against his favored enemies, a 3rd or higher level paladin against an enemy with a fear attack, a cleric against undead, etc. Some PCs will have a harder time defeating other challenges, e.g. a paladin against a non-evil opponent, spellcasters against creatures with good spell resistance, lightly armored characters against heavy hitters, etc.

I think this can be a major factor for a lot of EL anomalies. I threw some constructs in to an encounter and almost wiped the party as the DR and immunity to criticals negated the fighter rogue who had previously been creaming my monsters. Since i have a city based adventure, carrying a spare Glaive in your backpack isn't really an option and so DR in this setting is worth a lot more. Similarly the party cleric missed a week and a low level shadow wreaked havoc. the following session he returned and basically dismissed the final encounter with a couple of good rolls. (Undead may not be a good example since they are CR'd assuming the base 4 class party including cleric....)

How to play this in terms of EL? at the moment I increase the EL if the party hasn't the specific ability as its more of a challenge.

 

[awayfarer]

My current group OTOH, uses lots of battlefield control spells, tanglefoot bags, reach weapons, and focuses firepower for maximum effect. We have been able to take on much larger opponents because of this.

Ugh, don't remind me. I really hoped you guys might actually run from the giant labyrinth-dwelling freak.

 

[Shazman]

Hussar, you really hit it with tactics. One thing I've noticed adventures not using too much of is "crowd control" monsters. Hold, sleep, fear. Those kinds of things. Zap the guys with the low WILL save and beat the snot out of the PC spellcasters. Target the cleric and the wizard. However, this is not terribly fun.

Another issue is that D&D CR is based on combat. Lets take a troll and give him a level of expert. CR 7 or thereabouts, a little confusing because NPC levels count one less than PC levels, but let's call our troll CR 8. As a combat encounter, this is reasonably solid. Though why a DM would make a troll with all those skill points only to use him as cannon fodder is a mystery.

Now as a roleplay encounter things get weird. Let's say our troll has skill ranks in Perform (musical theater) and Knowledge (broadway hits). The troll will not hand over an item the PCs need for a quest until they help the troll put on a performance of The Music Man for the troll's true love. How exactly do we rate this encounter? What level is it appropriate for? As Hussar noted, what if the party is made up of four bards? What if the party has no bards at all? Do we let the PCs make a Perform skill check and call it a day? If they fail the skill check, how are they supposed to get the quest item without killing the troll? Because if they end up killing the troll, the DM may as well have made it a combat encounter.

A tricky thing to evaluate.

I know this is splitting hairs, but a troll expert 1 is a CR 5 just like a regular troll is. Since NPC classes increase CR by 1 less than their level, so 1-1=0. The same is true of non-associated classes, i.e. adding a single level of wizard to a minotaur. Back to the subject at hand, I firmly believe that creatures with PC classes are highly over CR'd. A hobgoblin fighter 4 is more like a CR 2 or 3 than a CR 4. I would say that for typical PC races Cr is equal to class level-2 for NPC classes and class level -1 for PC classes. Most CR 4 creatures would dwarf the 4th level fighter in hp, saves, attack and damage. In the case of adding associated classes to montrous races, that may not be the case. IMHO, a 2nd level bugbear barbarian is a solid CR 4.

 

[shilsen]

Something the WLD reminded at least one of us of:

If you assume that you can calculate the EL of multiple low-CR foes to create an appropriate EL encounter for higher-level PCs, you will be sorely disappointed. Derro caves, I'm looking at you.

That does depend on the DM, to a major extent. I can usually still challenge my group(currently a group of five very buff 13th lvl PCs) with a bunch of foes in the CR 4-5 range. Any lower would be a cakewalk, however.

 

[Phlebas]

I know this is splitting hairs, but a troll expert 1 is a CR 5 just like a regular troll is. Since NPC classes increase CR by 1 less than their level, so 1-1=0. The same is true of non-associated classes, i.e. adding a single level of wizard to a minotaur. Back to the subject at hand, I firmly believe that creatures with PC classes are highly over CR'd. A hobgoblin fighter 4 is more like a CR 2 or 3 than a CR 4. I would say that for typical PC races Cr is equal to class level-2 for NPC classes and class level -1 for PC classes. Most CR 4 creatures would dwarf the 4th level fighter in hp, saves, attack and damage. In the case of adding associated classes to montrous races, that may not be the case. IMHO, a 2nd level bugbear barbarian is a solid CR 4.

Just an observation - if you don't give all the goodies appropriate to the class level, then the CR +1 / level is really broken. Where theres a big difference between CR and Class level, then deciding what wealth level to use can also skew the calc.
If you kit the NPC's properly, and especially if you work them as a team, then you can get some very effective encounters for the CR

 

[Derren]

Imo this is also more or less important

1. Availiable sourcbooks
Most of the time when additional splatbooks are used, only the players use the new material in it while the monsters are used like the appear in the MM. And as splatbooks mean power, either through simply broken stuff (rare) or because they have materials in them with great synergy with materials from other books (common) the monsters end up weaker compared to the party because they don't use the splatbook material and are stuck with alertness etc.
If you use many splatbooks you might want to consider to use stronger monsters or to reboild you monsters with the splatbook material.

2. Preparatiotime/availiability
Being prepared for an encounter is a huge benefit in D&D if the players know which monster they are going to fight and have enough ressources to prepare for it they (often aided by metagaming) can kill the monster easily no matter what. Here to the number of splatbooks allowed is a cruical factor as the more splatbokks are allowed the higer the chance that somewhere there is the perfect instant kill spell for that monster.

3. Specialized builds
Several PRCs, but also feats spells and items, have been published by now which are specifically tailored to fight a single creature type with a very strong, imo sometimes overpowering effect (which people try to excuse with its limited scope). If the party has such things it makes encounters with that creature type a lot easier.
For example a challenging undead encounter for a normal group would be a cakewalk for a group with a Radiant Servant of Pelor. And a dragon encounter gets much easier when the party has a Dragon Slayer with the Dragondoom feat and special anti dragon items.

 

[Hussar]

That does depend on the DM, to a major extent. I can usually still challenge my group(currently a group of five very buff 13th lvl PCs) with a bunch of foes in the CR 4-5 range. Any lower would be a cakewalk, however.

I am honestly curious how you do this Shil. If your group has a core caster, either cleric or wizard, they've got access to 7th level spells. That's some very serious firepower - a single Mass Suggestion and most of that group is toasty. Or a Huge Elemental is going to blitz through CR 4 or 5 creatures badly.

I ran into this in the World's Largest Dungeon where they threw hordes of Formians and Derro at the 15th level PC's and they didn't even break a sweat.

Anyway.

Something else to keep in mind is that EL and CR build in some pretty hefty assumptions. The assumption, beyond the 4 core classes also pertains to the die rolls. It's effectively stating that in a standard fight with a standard party with average to hit rolls and average damage rolls, an EL=par encounter should use 20% of the party's resources.

The problem of course comes when the dice hit the table. An EL=par encounter can be a cakewalk or it can be a TPK (or nearly) just from a streak of good luck. If the PC's surprise an encounter, make some decent attacks during the surprise round, and then win initiative in the first round of combat, they just might drop the baddie before it gets a single attack in. OTOH, if the baddie gets surprise, jumps on the rogue with a solid whack, then wins initiative and makes a full attack, suddenly the rogue is a fine red mist settling over the landscape. Add in something like a cleave attack and the baddie has taken a chunk out of a second PC before they've even made a single attack.

EL and CR are most certainly not sciences. They are baselines to guestimate how an encounter should fall out, but, don't be surprised when things go pear shaped.