Calculating CR

[Kesnit]

I know somewhere, there is a table/list/something that has calculations to calculate CR of a creature. (I don't mean a creature out of the MM. I mean one made up out of whole cloth.) In our last session, the DM threw a homebrew encounter at the party that he called a "CR 3." I'm more inclined to call it "at least CR 20," but would like to have a basis for my thinking.


The party is 6 PCs of level 10 or 11.

While walking through the forest, the party came across a Tree standing over an unconscious gnome. Said Tree was clearly draining the life force of the gnome. The goal was to get the gnome away from the Tree.

Said Tree had:

32 HD
An attack bonus of over 29, since the DM was making called shots to the mouth, and said he only had to not roll a 1 to hit the PC with AC 25.
If a caster was hit twice by a called shot, they had to make a DC 15 or 20 (not sure which) to use a wand.
Touch AC of 27 or 28
Saves between 25 and 28
Enough melee damage to 1-shot any PC that came in range
Auto-heal to full every round
Psionic attacks that could only be blocked by psionic resistance/defense. (No magic-psi transparency)

[LOTRfan]

TheVorpalTribble created a very good CR calculator a while back. It was as follows;

#1. Divide creature's average HP by 4.5 to 6.5.
4.5 for 5 HD or lower, 5 for 6-10 HD, 5.5 for 11-15 HD, 6 for 16-20 HD., 6.5 for 20-25 HD.

#2. Add 1 for each five points above 10 its AC is, subtracting 1 for every 5 below.

#3. Add 1 for each special attack (+2 to +5 or more if its got a decent number of spells in its spell-like abilities).

#4. Add 1 for each quality unless you deem it worthy of more. Add 1 for each resistance and 10 points of DR it has, and 2 for each immunity. Subtract 1 for each vulnerability.

#5. Add 1 for every two bonus feats it has.

#6. Divide total by 3. This should be its rough CR

Assuming that the creature had 144 hit points (the average for a 32 HD Plant with a Constitution score of 10), the creature is CR 6 at a minimum (144 divided by 7.5 = 19.2, 19 divided by 3 is 6.3), and that is before you take into account its armor class and special abilities.

[Kelb_Panthera]

Even at a glance that's clearly much higher than CR 3.

I'd hazard a guess that you were supposed to snatch the gnome and run rather than try to stand and fight the thing. It's a poorly executed railroading attempt by my estimation.

It's also clearly homebrew. That heal to full each round ability doesn't exist in RAW as far as I know.

[Stux]

Did he actually say the encounter was CR3, not the creature? Because then perhaps there was simply a CR3 appropriate solution that you missed.

[Squirrel_Dude]

the DM threw a homebrew encounter at the party that he called a "CR 3."Are you sure it wasn't CR +3 (as in an encounter that is 3 levels above your party level. That clearly isn't a CR 3 encounter.



The party is 6 PCs of level 10 or 11.You should be facing CR 12 or 13 encounters on a regular basis, so if this is a CR +3, he would be between a CR 14 to CR 16.

Even with 32 HD, that might be possible, but it's unlikely.

[Kesnit]

TheVorpalTribble created a very good CR calculator a while back. It was as follows;

Thanks. That helps a lot. :smallsmile:


Even at a glance that's clearly much higher than CR 3.

I'd hazard a guess that you were supposed to snatch the gnome and run rather than try to stand and fight the thing.

That was the goal. However, since we could not get into melee range (and the tree was standing right over the gnome), the only way to grab the gnome was somehow neutralize the tree first.


It's also clearly homebrew. That heal to full each round ability doesn't exist in RAW as far as I know.

Based on the DM's explanation, it was using a psi power to drain the life force of all the living things around it. Since we were in a forest, that meant the trees. (The party was not being drained since the Tree had not had a chance to put psionic "hooks" in us. It tried on me, but I made my second save.)


Did he actually say the encounter was CR3, not the creature? Because then perhaps there was simply a CR3 appropriate solution that you missed.

He never gave a CR for the Tree. He said the gnome was CR 15, since our Truenamer asked so he would know how to roll his healing power. (That was before we realized the Tree was draining the gnome. At the time, we thought the Tree had beat up the gnome.)


Are you sure it wasn't CR +3 (as in an encounter that is 3 levels above your party level. That clearly isn't a CR 3 encounter.

No, I'm sure he called it CR 3. My wife and I asked him about it later, and he replied in a text with the CR.

[Kelb_Panthera]

You've never heard of harrying tactics and baiting?

Hit from outside its range in a position that it can't charge then, after you've got its attention and it's moving toward you, withdraw, rinse, repeat. Meanwhile someone sneaks in from the other direction and snags the gnome then everybody bugs out and leaves the evil tree scratching its head wondering what the heck just happened.

Even if it doesn't work it's immensely better than failing -and- getting mauled by an angry, killer tree.

Btw, why couldn't you get into melee range? I'm assuming some terrain feature made doing so too dangerous but not impossible?

[Kesnit]

Hit from outside its range in a position that it can't charge then, after you've got its attention and it's moving toward you,

1) We couldn't hit it. It's AC and saves were too high.
2) There was no "outside its range." Even from 60' away, it was hitting everyone on every throw. (And it had some ability that allowed it to target every PC on its turn.) Dropping an Entangle on it did annoy it enough to move it, but because it had to be dropped in such a way to not Entangle the party, the actual area of Entangle near the tree and the party was very small. (I think it moved 20' parallel to the road. Obviously, it made its save not to be Entangled.)


Meanwhile someone sneaks in from the other direction and snags the gnome then everybody bugs out and leaves the evil tree scratching its head wondering what the heck just happened.

Hiding was allowed, but not if anyone moved to get the gnome. "There are no trees on the road, so there is nowhere to hide." Also, "the tree is psionic and can see you through your minds."


Btw, why couldn't you get into melee range?

It would one-shot kill anyone it hit in melee. And it would hit anyone in melee. (Only by rolling a 1 would the DM not hit any of our AC's.) Even if the DM rolled low on a damage roll and someone survived a hit, they would actually have to at least 3 - 2 AoOs while moving in and out, and at least 1 on the Tree's turn.

[Bronk]

It sounds like there was confusion all around about this thing's CR, but maybe your DM was expecting you to lasso the gnome or something similar using magic.

Oh, or tying a rope around a character, waiting until the tree used it's actions, running up and grabbing the gnome, then having the rest of the characters drag both back...

[Chronos]

Wait, your party included a Truenamer? In that case, stupid rules can rescue us from other stupid rules. If the tree was a CR 3, then its True Speech DC was only 21-- You can hit that with your eyes closed.

[cerin616]

By these rules, shouldn't a 5 inch stone wall between you and your goal be cr 4?

EDIT: would beat that tree encounter by punching your dm square in the nose.

[Telonius]

Here's the "Improving Monsters (http://www.d20srd.org/srd/improvingMonsters.htm#advancedMonsterChallengeRati ng)" section of the SRD.

Given that, I think I can see what happened. DM thinks, "Hey, we have a 32-HD plant (+8 CR), Size increased to Large or Larger (+1CR), most likely Elite Array (+1CR), special attacks that increase combat effectiveness in a major (+2) and minor (+1) way, for a total of CR 13. Looks legit!"

If that's what happened, he's made a major error: that table is for improving existing monsters that already have a CR (however imperfectly that CR is determined). Auto-hits and full regeneration each round are worth a whole lot more than +1 or +2.

[Drachasor]

No, I'm sure he called it CR 3. My wife and I asked him about it later, and he replied in a text with the CR.

A typo where he left out the '+' seems likely. That said, he misjudged it's CR. He gave it the equivalent of Fast Healing 160 or more which is ridiculous. I'd point that out to him.


Anyhow, I find the CR guideline posted to be rather odd since it doesn't include damage. There's a huge difference between two creatures with the same stats except one has 6 natural attacks and the other just has one.

[Kelb_Panthera]

1) We couldn't hit it. It's AC and saves were too high.

Nobody had anything that could hit it? The truenamer at least should've been able to nail it with a reversed word of nurturing pretty reliably if the DM set it to CR 3.


2) There was no "outside its range." Even from 60' away, it was hitting everyone on every throw. (And it had some ability that allowed it to target every PC on its turn.) Dropping an Entangle on it did annoy it enough to move it, but because it had to be dropped in such a way to not Entangle the party, the actual area of Entangle near the tree and the party was very small. (I think it moved 20' parallel to the road. Obviously, it made its save not to be Entangled.)

60ft isn't all that far. It's the limit of range for a number of short range abilities but surely there was something you could do from further away.




Hiding was allowed, but not if anyone moved to get the gnome. "There are no trees on the road, so there is nowhere to hide." Also, "the tree is psionic and can see you through your minds."

You hide -until- the opportunity to grab the gnome is presented. Then you rush in, grab him, and flee as fast as possible.

That it had mindsight is a bit much.




It would one-shot kill anyone it hit in melee. And it would hit anyone in melee. (Only by rolling a 1 would the DM not hit any of our AC's.) Even if the DM rolled low on a damage roll and someone survived a hit, they would actually have to at least 3 - 2 AoOs while moving in and out, and at least 1 on the Tree's turn.

One instance of movement can only provoke one AoE from each threatening creature, no matter how many of a creature's threatened squares you move through. Unless the creature has combat reflexes it's not getting more than one in a given round, period.




All that said. This was clearly a terribly misguided setup. I don't know what your DM thought this would accomplish but he seriously flubbed something here.

[WhamBamSam]

That was the goal. However, since we could not get into melee range (and the tree was standing right over the gnome), the only way to grab the gnome was somehow neutralize the tree first.Summon Monster I+Benign Transposition. The Gnome is safe and no one faces any real risk except your summoned minion, unless the Psionic abilities somehow cause this not to work.

Two first level spells is about CR3, though just because it's CR3 for a Shrodinger Wizard doesn't necessarily mean it's CR3 for anyone else. A decently optimized high tier party probably could have handled this without much trouble at ECL 10-11 without preparing for it, but encounters really shouldn't be CR'ed based on what full casters can do against them.

You had a Truenamer in your party, so I'm assuming that as a whole you guys average out to T3 or T4ish. There might have been a solution to this that you didn't see, but you're probably right in thinking that this was above your pay grade.

Out of curiosity, what are the classes in your party?