Challenge Ratings

[taliesin15]

I've been playing 3.0 for almost 5 years (longtime 1st edition DM/player), and have been having some fundamental questions with Challenge Ratings.

First--what would the CR be for a party (PCs or NPCs, doesn't matter) for a party of 4 1st LVL adventurers? Let's assume they are Fighter, Wizard, Cleric and Rogue.

 

[Ruslanchik]

Unless I'm mistaken, all PC class characters have a CR equal to their character level.

 

[Jhaelen]

Yep. Unless a race with a Level Adjustment (LA) and/or racial Hit Dice are involved a pc with class levels has a CR equal to his/her level.
If the pc has levels in an NPC Class, the CR is equal to the character level - 1.

So, if you'd like to create an encounter with a npc party of four level 1 characters the encounter level would be about 4 (the progression for CR1 enemies is a bit irregular; normally you'd add 2 to the EL for each doubling of the number of enemies...).

 

[taliesin15]

CR 4--yeah, that's what I thought, but found a few references suggesting such a party would be CR2, which didn't make sense at all to me. IOW, a fight with with 4 Orcs, given they are CR 1/2, should be, all things on balance, an easy fight for 1st lvl adventurers. A fight with 6 Orcs (or a few more) would be more balanced.

Its been a while since I've run 1st lvl adventures, and I was wondering if I was missing something or the rules were stated a bit vaguely there.

 

[taliesin15]

Back to Challenge Ratings. If a party of 4 1st LVL Characters is CR 4, then an equal challenge would be a CR 4 Monster, 2 CR2 monsters or a party of 4 CR1 monsters, right?

Well, what about this, p. 100 of the DMG (3.0)

"A monster of CR 5 is an appropriate challenge for a group of four 5th lvl characters."

Wouldn't such a monster be easy pickings for four 5th lvl characters?

OTOH, a CR20 monster would be wa-aa-aayy too powerful.

Seems to me an encounter with 4 CR 5 monsters would be an even fight with a party of 4 5th lvl Characters.

 

[Herzog]

the encounter rules consider the fact that you are expected to face approximately 5 challenging encounters per day.

an encounter of CR equal to your level should consume 20% of your parties (dayly) resources.

After 5 of such encounters, the wizard and cleric will be out of spells, and continueing would be dangerous.

A group of 4 first level NPC's is a EL4 encounter, because they can use up all their resources in that single combat and, assuming the PC's win, the PC's will have to spent far more than 20% of their resources to overcome that challenge.

Herzog

 

[werk]

Back to Challenge Ratings. If a party of 4 1st LVL Characters is CR 4, then an equal challenge would be a CR 4 Monster, 2 CR2 monsters or a party of 4 CR1 monsters, right?

Well, what about this, p. 100 of the DMG (3.0)

"A monster of CR 5 is an appropriate challenge for a group of four 5th lvl characters."

Wouldn't such a monster be easy pickings for four 5th lvl characters?

Right and not so right.

A CR5 monster should be a fair fight for a standard party of 5th level characters assuming they are 5th level which includes standard point buy (or ability score range) along with wealth (equipment) and in equally advantageous conditions.

If you have a party of really high statted primo-equipped bad-asses, then yes, the CR5 monster would be a piece of cake, but that's because you've underestimated the power of the party by not taking everything into account. Same applies to setting up the encounter to favor one side or the other, for instance a kobold lair becomes a lot more difficult because it is stacked in favor of the kobolds with traps/terrain/etc.

Say for instance, and this is a crazy example, but let's say a ranger is able to sneak into a white dragon's lair where an old dragon is found sleeping, helplessly trapped under a layer ice, and the ranger is able to kill the dragon by dropping a giant stalactite precariously dangling overhead. Even though the CR of the monster may be much greater than the party, the challenge as presented is much much less so and the party should not be rewarded with full XP based on the monster's CR alone.

Due to so terribly many variables, many of which are unknown to the players, XP awards are pure estimation by the DM using CR as a starting point. Many of us here prefer to reward xp as we see fit to advance the campaign as best suits the players and DM.

 

[Jhaelen]

Well, what about this, p. 100 of the DMG (3.0)

"A monster of CR 5 is an appropriate challenge for a group of four 5th lvl characters."

Wouldn't such a monster be easy pickings for four 5th lvl characters?

Well, it certainly won't be difficult. This is supposed to be a (somewhat misleadingly called) 'challenging' encounter. A level 5 party is supposed to be able to deal with four of these in a given day without problems, since each encounter should cost them about 20% of their resources.

Seems to me an encounter with 4 CR 5 monsters would be an even fight with a party of 4 5th lvl Characters.

Correct, however an 'even' fight in this case means about a 50% chance of failure! This is something you generally shouldn't do often.

4 CR 5 monsters are an EL 9 encounter. This is a 'very hard' encounter, supposed to cost the party 80% of their resources.

What are these resources anyway? Well, mostly spells and hit points, sometimes also magic items. Here's my point of view on resources:

An encounter with an EL equal to the party's level is generally a 'safe' encounter for a party of four because each of them is supposed to lose only 20% of his/her resources: If you add these up you get a total of 80%, i.e. if only one character is losing any resources, she'll still have 20% left.

An encounter with an EL of (party level +4) on the other hand is quite dangerous. There's a realistic chance of a dead character because in total they're going to lose 160%. It's not possible for a single character to lose that many resources, so one potential result of such a fight would be one character losing 100% of his resources (i.e. dying) and a second losing 60% of her resources, while two of them don't lose anything at all.

This is why encounters of this difficulty are best reserved for boss fights. If there's no other encounter after it, the characters should be fine.

Note, that an encounter with an EL of (party level +5) or more is supposed to be 'overpowering'. This is mostly because these encounters are extremely 'swingy'. A streak of bad luck at the beginning of such an encounter will likely doom the entire party.

Edit: There are also several browser-based calculators available, like this one.

What werk was referring to - an this is also definitely worth considering - is the degree of power-creep in your campaign. The more splatbooks your players are using when they build their characters the more likely are they to be more powerful than their CR indicates.

Similarly, the later Monster Manuals contain several monsters that are lot tougher than their CR seems to indicate - at least compared to a MM1 monster of equal CR.


A final comment:
Since you seem to have the 3.0 DMG, just have a look at page 102. It shows the recommended percentages for the different encounter difficulties. The table is just as true in 3.5.
I'm using it all the time with mostly good results.

For 'random' encounters I use encounter levels of (party level -2) to (party level +4). In a given day there can be 0-6 encounters (I roll 1d6 / 4 hours, a 1-2 results in an encounter).

For 'random' encounters I stopped using 'overpowering' encounters, since it's not very satisfying to have one or more dead characters after an encounter that is not meant to be particularly significant.

I still use them in 'planned' encounters, though. I believe it's a good thing to include encounters that are not meant to be defeated every once in a while. Otherwise the players get careless. Your mileage may vary of course.

 

[taliesin15]

Thanks for your feedback, folks.

So what you're saying is even fights, let's say 4 Bugbears vs. 4 2nd lvl PCs, tend to result in more than a 20% depletion (closer to 50%) of character resources?

XP aside, the formula of 13.33 CR-appropriate encounters for raising a level should, on average, be ones that balance out to a 20% depletion of party resources?

I can understand that doing so promotes the "dungeon crawl" paradigm. Honestly, I've always designed encounters that I thought were appropriate based on previous experience, and never thought that much about Challenge Ratings. I always use the 13.33 guide for levelling up, and not the XP. I guess I've always assumed that the CR was a mechanism for determining fair and close to equal fights, when actually it looks like they tend to be weighted to favor the PCs.