A Thought About CR

[D'karr]

We get two sentences relating CR to appropriate challenge. Then we get about a page and a half showing how to use it to calculate XP.

I'm not sure which DMG you are looking at but starting on Page 100 and continuing for the next 2 pages it explains in rather great detail how to prepare encounters for adventures. There is even a sidebar explaining some of the thought process behind it. It seems like a lot of people complaining about how CR is "this or that" haven't actually ever looked (much less read) the information on those pages.


XP calculations have nothing to do with adventure preparation. That is covered by a table about 60 pages later.

 

[I'm A Banana]

CR should be determined by an encounter that would push a party to its limits- basically having a 50/50 shot at winning.

Why?

I never understood why they chose an encounter with a CR equal to the party's as depleting 20-25% of their resources. It seems like a completely arbitrary number, especially since what comprises 20-25% of a party's resources will vary greatly from party to party, but an encounter that pushes them to the make or break point will be more uniform (though still not perfect).

1) The 50/50 chance is arbitrary. The 20-25% was based on research that said most groups prefered to have about 13-14 encounters per level, and thus diseminated into the XP system.

2) 20-25% of resources will not vary greatly form party to party. Just stubtly. Following the guidelines on treasure and XP awards, it can be resonably determined what the 'resources' of a 'typical' party will be.

3) What makes a 50/50 chance more uniform?

The 20% number is an unrealistic number because it is counter-intuitive and difficult for a DM to estimate easily. When you design encounters, do you design them to be even CR with a group (a cakewalk), or more challenging?

1) 20% is not unrealistic or counterintuitive or difficult for me to estimate easily. About 4-5 encounters between resting periods, about 3 'periods of rest' per level.

2) My group tends to like a faster pace of level and resource gaining, so I design the encounters to be more challenging, sucking up 50-100% of their resources per encounter, with only one or two resting periods per level. Effectlively, this churns out to 1-3 encounters per level. Since my characters gain levels about five times as fast as the average party, I have to mutliply the treasure by five, too.

Doesn't assigning a CR based on an even-odds fight make more sense than trying to figure out how many encounters of a given CR would deplete 25% of resources?

No, because most parties aren't fighting one or two battles per level, they're fighting around 13-14.

(stuff about the point of CR)

CR's are an approximation of a monster's toughness first and foremost. The toughness of the monsters you fight compared to your own ability to handle that toughness dictates how much XP you gain, which therefor dictates how quickly you advance.

CR isn't used for calculating XP directly -- the toughness of a monster vs. your party's touchness is what's used to calculate XP directly. CR is a numerical represetnation of a monster's toughness that can easily be plugged into a formula to determine how much XP something of that toughness is worth.

 

[Umbran]

I was just thinking about CR and what it is supposed to mean, and something just occurred to me. CR should be determined by an encounter that would push a party to its limits- basically having a 50/50 shot at winning. I never understood why they chose an encounter with a CR equal to the party's as depleting 20-25% of their resources. It seems like a completely arbitrary number...

It isn't arbitrary. Try thinking about it this way - the system is set up with respect to the encounters you'll use most frequently.

Most games are not constructed of encounters for which it's a coin toss of whether the party survives. Usually, an adventure is constructed of a number of encounters that slowly wear the party down, perhaps building towards something particularly tough.

 

[Grog]

CRs are worthless. Abso-freaking-loutely worthless. Even as a guide. A girallon is a CR 5 monster that can reduce a 7th level fighter from full hit points to below -10 in one round. The vrock is listed as CR 13 (high) and the bebelith is CR 9 (low). Dragon CRs are completely out of whack. So many of the numbers are just flat-out wrong that using the CR system causes much more problems than it solves IME.

 

[I'm A Banana]

A girallon is a CR 5 monster that can reduce a 7th level fighter from full hit points to below -10 in one round.

This is why the fighter needs the cleric. And why the wizard should be tossing fireballs and lightning bolts at the creature from a distance. And why the party needs to stay generally away from it unless it can only get off one attack.

The Girallon is a fine CR5 monster, as it will drain a party's resources -- but not wipe them out. With a rogue, a wizard, a cleric, and a fighter, the guy's nothing more than a tough physical customer. Charm him, hold him, slow him, ranged attack him -- he can't touch you and he's meat in a matter of rounds.

Not every monster problem should be solved by going up next to it and hitting it on the head until it dies. Sure, a CR5 Fey may be the perfect victim of that, but a big four-armed gorilla? You expect it to hit like a pansy little elf?!

 

[The_Gneech]

Maybe I should put my point into different words. All I was trying to say was that as you get large numbers of variables and wide ranges of randomized numbers flying around, predicting how a combat will go in D&D or in any system becomes increasingly like trying to forecast the weather -- difficult and sometimes downright impossible for even the best tools!

I will grant that CR can be useful in the vaguest "broad brush" sort of way; but you can't simply plug in 4 combats at the party CR and know they'll need to rest, for instance. My point was just that isn't useful for gauging the result of any given combat.

-The Gneech

 

[Zappo]

All too often, I have the feeling that people expect of CR more than what can reasonably be expected. CR works wonderfully for the simple tool it is. Anyone here really thinks that WotC should have devised a system that provides with anything more than a guideline to the creature's overall power?

Most definitely, I think that anyone who expects CR to allow him to pick three random monsters and call it a balanced encounter is delusional. It doesn't work for that - well of course it doesn't. That would be a miracle.

 

[BryonD]

All too often, I have the feeling that people expect of CR more than what can reasonably be expected. CR works wonderfully for the simple tool it is. Anyone here really thinks that WotC should have devised a system that provides with anything more than a guideline to the creature's overall power?

Most definitely, I think that anyone who expects CR to allow him to pick three random monsters and call it a balanced encounter is delusional. It doesn't work for that - well of course it doesn't. That would be a miracle.

You are exactly correct. But WotC represented the system as working much better than a guideline. A reading of the DMG leaves one to think that CR leads directly to XP and that some times special circumstances should lead the DM to modify it. But the default assumption is that the system works better than could reasonable be expected to really do.

I think the reason for this is that, for a large group of casual gamers, a fixed, purely mathematical *correct* answer is better than an open-ended interpretational system. Even if that *correct* answer has wildly varying degrees of error. I think ENWorld is strongly slanted towards gamers who take these matters more seriously than the average 3E player, many of which never come here. IMO, this error bothers us a lot more than many others.

So, IMO, it is fair for people to expect WotC to do what is really impossible, because WotC said they would. But at the same time, WotC should be able to say that they did do the impossible, they just had to very allow a large margin of error to get there. People, such as myself, who want a more consistently accurate system should understand this, and give WotC a break.

 

[mmadsen]

So what exactly is the complaint? That a single number can't capture how challenging a monster is in every situation? That the number represents the wrong thing? That people put too much faith in the number?

 

[Petrosian]

IMO, the best thing that can be done for the CR system is to take the section on scenario setups to CR/El where they discuss orcs in ambush vs orcs in the open and expand it into about 10 pages of scenario design 101.

IMX with 3.0 the significance of scenario setup is grossly understated. Whether a party is buffed for combat, buffed for the day, or caught totally unawares is a drastic 500 lb gorilla of a threat assessment after just a few levels.

Having seen way too many "our party is being straffed by an Imp invis flying wizard in the open and our Dm wont quit" threads, as well as too many "ogres are not CR 2!!!" when the presupposition is that ogres start at full attack melee range and even once when i saw a guy screaming about how wrong the CR was for a critter that had 7 attacks because it mauled his fighter and whole party... after they ignored that it was an open street encounter and the critter has only a 10' move per round when they CHOSE to rush to full attack melee range and stay there... there is clearly a need for some very decent scenario design instructions to help these Gms and players figure out what a "situationally broken" encounter is and how to avoid it.

yweaking the Crs is useless without helping them understand the setup issues involved.

Now i have seen in 3.5 that some of the critters are getting a "first few rounds" tactical plan included. if done well, these might be a step in the right direction.

FWIW, in my games, less than 1 ogre in 10 ever got to melee range when my guys were at levels 2 and 3. Lumbering morons with negative hide and silent scores and no reasonable ranged capability just do not seem all that effective. My bugbears were a lot more of a threat.