What's the CR for Class Levels?

[Cheesegear]

As the title says.
I'm sure there must be some guideline I've missed in the DMG or Xanathar's.

If I was to give a Hill Giant Ranger classes, with a Dire Wolf as his Animal Companion...What would be the CR?

[BurgerBeast]

Believe it or not, there is no straightforward method to do this, and this is mostly because in 5e, the mechanics for monsters and those for PCs is entirely separate.

The best way to do what you’re asking is to give the Hill Giant “monster versions” of the Ranger abilities that you are trying to emulate. Then, calculate the new CR.

The reason I say “monster versions” is because many PC abilities have more-or-less equivalent abilities that are more appropriate to monster stat blocks. For example, multi-attack instead of extra attack.

[PhoenixPhyre]

BurgerBeast is correct. CR and class levels are only very weakly correlated.

Best (and quickest) method: give the monster abilities that are evocative of the class. Here, an animal companion and a few spells. Treat the companion as a separate monster for encounter balancing, but play it like a companion (obeying his commands, etc). Ranger spells rarely have any significant effect on CR, so they're generally a wash.

Rule of thumb: CR changes by +-1 if
a) effective HP[1] changes by +-30,
b) DPR[2] changes by +-12, HP unchanged (relatively)
c) AC changes by +-4
d) ATK changes by +-4
e) 50/50 split (in the same direction) for c and d
f) 50/50 split (in the same direction) for a and b

a, b, c, and d all assume no other significant changes.

[1] effective HP includes the multipliers for things like resistances and the contributions from Legendary Resistances. See DMG section.
[2] 3-round, best-case (everything hits, all aoes hit 2 people, all saves failed), average-damage-rolls, best-attack-routine DPR as defined in the DMG. Includes DPR from traits (see table).

[LudicSavant]

Like BurgerBeast said, there is no direct translation from class levels to CR established in the rulebooks, AFAIK.

You can however find out their offensive and defensive challenge rating using the method described in "Creating a Monster" in the DMG. Same as you do for other custom monsters.

[SanguisAevum]

Like BurgerBeast said, there is no direct translation from class levels to CR established in the rulebooks, AFAIK.

You can however find out their offensive and defensive challenge rating using the method described in "Creating a Monster" in the DMG. Same as you do for other custom monsters.

There has been a fair bit of work done by the fella at blog of holding, to establish that the DMG version of "creating a monster" is not quite the rules that the designers use themselves. (IE - it doesn't tie with MM monsters for example)

He created a better solution to designing monsters for 5e... which is supported by a lot of analysis.
If your interested in creating your own monsters for 5e, i recommend you use this, and read all the analysis he did as well.. it's interesting stuff and gives a good insight into the mechanics of Monster CR in 5e.

LINK (http://blogofholding.com/?p=7338)

[LudicSavant]

There has been a fair bit of work done by the fella at blog of holding, to establish that the DMG version of "creating a monster" is not quite the rules that the designers use themselves. (IE - it doesn't tie with MM monsters for example) I'm already aware the devs use a different system. They've talked about it being based on their own judgment as designers, playtests, etc.

Thanks for the link though, I'll take a look :smallsmile:

[PhoenixPhyre]

There has been a fair bit of work done by the fella at blog of holding, to establish that the DMG version of "creating a monster" is not quite the rules that the designers use themselves. (IE - it doesn't tie with MM monsters for example)

He created a better solution to designing monsters for 5e... which is supported by a lot of analysis.
If your interested in creating your own monsters for 5e, i recommend you use this, and read all the analysis he did as well.. it's interesting stuff and gives a good insight into the mechanics of Monster CR in 5e.

LINK (http://blogofholding.com/?p=7338)

That post, while interesting, misses a few huge points. It doesn't take into consideration resistances and immunities at all, for example. This means that his "nice simple lines" just aren't that way when you actually look at effective health rather than on-book HP. I have a spreadsheet in my signature with all the monster data. Very few are off from their DMG values by very much, and the average swing from their "book" CR is small (< 1 over any reasonable subset of the table).

And his data hides the large swings within individual monsters by mushing monsters into aggregates. Offensive and Defensive CR often vary by quite a bit; "averaged" (oCR = dCR) monsters tend to be unsatisfying in my experience, and that's all his system gives.

For rough numbers and non-special monsters, it's ok. But it's got large flaws.

Edit: and as LudicSavant says above, CR is just a rough ballpark anyway. Playtesting monsters is key. The ones that differ from their DMG values are likely so due to playtesting. They've specifically called out the Ogre (by-the-book CR 1, real CR 2) as hitting too hard for being a CR 1.

Offensive CR indicates whether the creature has a decent chance of knocking out (reducing from 100% to 0 HP) a "weak" character of level = CR - 1 in a single turn.
Defensive CR indicates whether the creature has a decent chance of surviving for 3 rounds against roughly equivalent foes.

Edit: as a quick look, his "DPR = HP/3 number is just wrong. The average deviation from this across all CRs is 7.33--that is, DPR is approximately HP/3 + 7, but with huge swings in both directions (from +30 to -41). So it's a trick of his (improper) aggregation of monsters. He's getting data points from separate monsters confused.

[LudicSavant]

I have a spreadsheet in my signature with all the monster data.

Oh hey, that's handy! :smallbiggrin:

[PhoenixPhyre]

Oh hey, that's handy! :smallbiggrin:

Thanks! I can't claim the DPR numbers are perfect, but they seem to match the DMG guidance pretty well, so they can't be too bad. Spellcasters are hard to do, however :smallmad:

It's got everything from all the major monster books. None of the adventure paths, because I don't own any of them.

[Lalliman]

If you're going to recalculate the CR of a modified creature, use this site so you don't have to do the math yourself: https://5etools.com/crcalculator.html#3,13,20,8,false,Medium,24,10,fal se,0,false,0,

I find that the CR table works well once you understand its idiosyncrasies, and if you apply sufficient common sense. Beware that a creature should almost always have Offensive CR higher than Defensive CR, because having them at the same level leads to a highly-defensive creature (as PhoenixPhyre alluded to). Also note that most published monsters are underpowered according to the CR table, so adherence to the CR table may make monsters more powerful than you're used to. I consider that a benefit, but YMMV.

[PhoenixPhyre]

If you're going to recalculate the CR of a modified creature, use this site so you don't have to do the math yourself: https://5etools.com/crcalculator.html#3,13,20,8,false,Medium,24,10,fal se,0,false,0,

I find that the CR table works well once you understand its idiosyncrasies, and if you apply sufficient common sense. Beware that a creature should almost always have Offensive CR higher than Defensive CR, because having them at the same level leads to a highly-defensive creature (as PhoenixPhyre alluded to). Also note that most published monsters are underpowered according to the CR table, so adherence to the CR table may make monsters more powerful than you're used to. I consider that a benefit, but YMMV.

They're not underpowered. The average deviation from book value is -0.07 (where negative means that book CR > calculated CR).

If you only look at base health, they have low health (compared to book value) but that's because the book value is for effective health, after adjustments based on resistances, etc.

[Ninja_Prawn]

The average deviation from book value is -0.07 (where negative means that book CR > calculated CR).

I've not looked at the statistics, but I wonder if there might be a handful of specific monsters that are over-CRed in the book, and they're skewing perceptions because they happen to get used more often than the under-CRed monsters? That sort of thing could get missed by average values.

Anyway, I generally agree with the advice elsewhere in the thread so I don't have much else to add. Except maybe to offer a hand to the OP if they have a particular honebrewed stat block they'd like me to calculate the CR for. I'm happy to deal with that sort of thing by PM.

[darknite]

It's like asking how many florins per quatloo. It's a nonsensical concept and doesn't really compute.

[tchntm43]

Using player stats for hostile NPCS can be done, but you have to be prepared to modify the results quite a bit. Usually this means multiplying final hit points by around 1.5 and the damage to around 0.75. The game is designed for characters to deal more damage than monsters, and for monsters to have higher hit points than characters. There's no direct CR comparison, but you can use the CR guide to find what you want for hit points and damage, and then add levels to the character until you have the numbers you want.

[Lalliman]

They're not underpowered. The average deviation from book value is -0.07 (where negative means that book CR > calculated CR).

If you only look at base health, they have low health (compared to book value) but that's because the book value is for effective health, after adjustments based on resistances, etc.
Perhaps I'm thinking of a subset of creatures that is not representative of the whole. But there is also ambiguity in determining effective HP, because the DMG gives rules on what percentage to increase the effective HP by, but leaves it to you to determine how many resistances are needed to warrant applying it. It also foolishly states that vulnerabilities have no effect on effective HP. As such, you gave the treant +50% effective HP, which I wouldn't give it because its vulnerability to fire cancels out its resistance to bludgeoning and piercing. It's possible that different applications of the guidelines have led us to different conclusions.

[PhoenixPhyre]

Perhaps I'm thinking of a subset of creatures that is not representative of the whole. But there is also ambiguity in determining effective HP, because the DMG gives rules on what percentage to increase the effective HP by, but leaves it to you to determine how many resistances are needed to warrant applying it. It also foolishly states that vulnerabilities have no effect on effective HP. As such, you gave the treant +50% effective HP, which I wouldn't give it because its vulnerability to fire cancels out its resistance to bludgeoning and piercing. It's possible that different applications of the guidelines have led us to different conclusions.

I use the general rule of
* below T3, the standard non-magical BPS counts. T3 or above, you need immunity to non-magical BPS or resistance to all BPS to count
* anything with as many elemental resistances as, say, your average devil counts.
* If it's just one or two, it doesn't count.

And there's a lot of monsters there with resistances/immunities. Very very few have vulnerabilities. Like, 10, max. Out of 700+. So no, those don't significantly alter the case. Anyway, the variability in calculating DPR (especially for casting-focused monsters) is way bigger than that.