gladiusdei
 member, 591 posts
Sun 26 Nov 2017
at 03:34
D&d 3.5 question on challenge rating for altered monster
I have a question on how to determine the challenge rating of a monster if it is shrunk.  The normal monster is huge or bigger, how much would the cr go down if that creature was shrunk to medium size.  It would do less to damage with its physical attacks and lose some of them, but still retain its stats.  Just trying to figure out how big of an impact that would make on a monster's lethality.
Ramidel
 member, 1348 posts
 Err on the side
 of awesome.
Sun 26 Nov 2017
at 05:46
D&d 3.5 question on challenge rating for altered monster
This is the table for determining how damage is altered by size in 3.5. Just pick a damage level that matches its power at Huge size and adjust to Medium:

http://www.d20srd.org/srd/equipment/weapons.htm

This message was last edited by the user at 05:47, Sun 26 Nov.

gladiusdei
 member, 592 posts
Sun 26 Nov 2017
at 06:06
D&d 3.5 question on challenge rating for altered monster
Yeah, I know how to alter it.  Just trying to figure out how that alteration would be reflected in its challenge rating.
meschlum
 member, 179 posts
Sun 26 Nov 2017
at 08:51
D&d 3.5 question on challenge rating for altered monster
Really depends on the monster. If it has spellcasting and usually avoids melee, keeping the same abilities and being harder to hit (and having an easier time hiding) is wholly beneficial. If it's meant to be involved in melee, it'll be a lot less effective...

Taking humanoids as an example, you have Medium humanoids ranging from CR 1/2 (Orc) to 3 (Bugbear), Large going from 4 (Ogre) to 10 (Fire Giant), and Huge going from 11 (Cloud Giant) to 13 (Storm Giant). So the reduction in size (and special powers) could be in the 12 CR range (Storm Giant to Orc). If you look at the transition to Ogre from Bugbear, it's a +1 CR, so going from Huge to Medium would be more like -2 CR.

A range of monsters that increase in size as they gain hit dice seem to change size when their CR goes up by ~2 or so, suggesting that a size increase (with extra hit dice for even bigger numbers) is worth around 2-3 CR. This work with the Orc -> Ogre transition. So going down in size without losing hit dice would probably reduce CR by 1-2 per step.

Again, it really depends on what you're looking at and how affected it is by the size change.
DarkLightHitomi
 member, 1236 posts
Sun 26 Nov 2017
at 10:29
D&d 3.5 question on challenge rating for altered monster
You shouldn't really worry about CR. The CR system is nothing more than a benchmark anyway, to get a good ballpark estimate for building encounters. As it is merely a ballpark estimate that needs to be adapted to your individual group per encounter anyway, it isn't really much help to you at all, except perhaps to communicate your experience with the monster's difficulty to other GM's, and if you plan on doing that, then you really need to test the monster out a lot and compare how easily your group defeats the monster compared to other monsters and give a CR rating similar to monsters that gave your group a similar amount of difficulty.
gladiusdei
 member, 593 posts
Sun 26 Nov 2017
at 14:56
D&d 3.5 question on challenge rating for altered monster
Thanks for the help.  I know, cr is a pretty annoying system, honestly.  Just trying to develop a few scenarios, and I don't want them to seem grossly unfair.  So I was trying to at least use cr as a rough guideline.  But I think I can manage now.