I'm trying to understand how CR is really working. For specific and irrelevant reasons, I've started by trying to reverse engineer the Necromancer. So I start from the DMG workshop and I crunch the numbers.
Defensive Challenge Rating
The dude has 66 HP and an AC of 12, but if we assume he starts off with Mage Armor and Stoneskin, we can think of him as a 132 HP AC 15 beast. Which, according to the tables, gives a defensive challenge rating of 5.
Offensive Challenge Rating
Stronger spell is an AOE and I don't know how to deal with this. I'm going to assume an average of 2 PCs in the AOE and disregard save (since To-hit / Save DC are factored later in the equation).
So basically our Necromancer best damage outputs are:
Circle of death, avg 72 dmg (36 each), one use Cloudkill, avg 45 dmg (22.5 each), two uses Blight, avg 36 dmg (single target), two uses
Which gives us a 5-round average of 46.8, a CR 7 value. Save DC of 15 is coherent with this assessment.
Average CR would then be 6
VGtM places the Necromancer at CR 9 but I'm 3 points short of that and I have no clue how to bridge the gap.
Unless Animate Dead is worth 3 whole points of CR because HP-bags and action economy?
(What I'm actually trying to do is to downgrade that duderino to CR 4, but I don't know how many caster levels to remove)
Have you looked up any other CR 4 casters to see what caster level they are? Most of the ones that I found seem to have a cut off at around 3rd or 4th level spells.
Depends a lot on the base monster. I found exemple as low as 5th level and as high as 11th.
I don't think I'll exceed 7th, since I'm sure I'll kill them all, but I'd really like to crack the maths behind the assigned CR. Building encounters we put lot of trust in those numbers and it's nagging me how little I understand them.
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Hi fellow DMs
I'm trying to understand how CR is really working. For specific and irrelevant reasons, I've started by trying to reverse engineer the Necromancer. So I start from the DMG workshop and I crunch the numbers.
Defensive Challenge Rating
The dude has 66 HP and an AC of 12, but if we assume he starts off with Mage Armor and Stoneskin, we can think of him as a 132 HP AC 15 beast. Which, according to the tables, gives a defensive challenge rating of 5.
Offensive Challenge Rating
Stronger spell is an AOE and I don't know how to deal with this. I'm going to assume an average of 2 PCs in the AOE and disregard save (since To-hit / Save DC are factored later in the equation).
So basically our Necromancer best damage outputs are:
Circle of death, avg 72 dmg (36 each), one use
Cloudkill, avg 45 dmg (22.5 each), two uses
Blight, avg 36 dmg (single target), two uses
Which gives us a 5-round average of 46.8, a CR 7 value. Save DC of 15 is coherent with this assessment.
Average CR would then be 6
VGtM places the Necromancer at CR 9 but I'm 3 points short of that and I have no clue how to bridge the gap.
Unless Animate Dead is worth 3 whole points of CR because HP-bags and action economy?
(What I'm actually trying to do is to downgrade that duderino to CR 4, but I don't know how many caster levels to remove)
Have you looked up any other CR 4 casters to see what caster level they are? Most of the ones that I found seem to have a cut off at around 3rd or 4th level spells.
Depends a lot on the base monster. I found exemple as low as 5th level and as high as 11th.
I don't think I'll exceed 7th, since I'm sure I'll kill them all, but I'd really like to crack the maths behind the assigned CR. Building encounters we put lot of trust in those numbers and it's nagging me how little I understand them.