Originally Posted by
quindraco
Copper is harder, because I have no idea if or how the slowing breath should impact offensive CR.
Defensive CR: HP 22 is CR 1/8, adjusts to 1 + 1/8 for AC, adjusts to 2 + 1/8 for saves.
Offensive CR: Breath weapon (acid) is DPR 12 at save DC 11. Bite is DPR 7 at +4 to hit. That's average DPR (7*2+12)/3 = 26/3 = 8 2/3. Rounded down to 8, that's DPR 8, or base CR 1/2.
Adjustment based on hit bonus: 1/2.
Adjustment based on save DC: -1/2, so 0.
The average of 2+1/8 and 0 is 1. The average of 2+1/8 and 1/2 is 1. Since the monster is listed as CR 1, I don't know how you got 1.5.
I very much appreciate you spending the time to work through these @quindraco (why isn't there a formal way to reference peeps in giantitp?). In your calculations, you used a breath weapon DPR of 12 when it is actually 18.
Here's what my code produces:
Code:
CopperDragonWyrmling
Inputs:
- iCR: 1 (initial estimate, affects computed attack bonus)
- HP : 22 (4d8 + 4; avg 18 + 4HD*+1 (Con 13))
- AC : 16 (dex=1,natural=15)
- Att: 4 (+2 prof bonus from CR 1, +2 for Str 15)
- DPR: 17
- Att1: acid breath (18) against 2.0 targets once per 3.0 rounds
- Att2: bite (7) against 1.0 targets once per round
- DPR = 18*2*0.333 + 7*1*0.667 = 12.0 + 5.0 = 17.0
- dmg is more from effects with saving throws (12) than attacks (5)
- RIV
- immunity to acid
Adjustments:
- resistances/immunites: 1 immunity
- no impact on CR
- saves: proficient in 4 (dex,con,wis,cha)
- increases effective AC by 2
Outputs:
- dCR: 2.125 (0.125 + 2) = 2
- effective HP=22 suggests AC 13 and CR 0.125
- adjust dCR by 2 ((effective AC - expected AC)/2 = (18-13)/2)
- oCR: 1 (2 + -1) = 1
- dmg is more from effects with saving throws than attacks
(using Save DC rather than Attack Bonus in DMG-274 table)
- effective DPR=17 suggests DC 13 and CR 2
- adjust oCR by -1 ((effective. dc - expected dc)/2 = (11-13)/2)
- fCR: 2 ((2 + 1)/2 = 1.5)
Summary:
/-----+------+------+-------+-----+----+-----+---------------------------\
| Var | Act. | Eff. | Def | Off | Δ | Res | Notes |
|-----+------+------+-------+-----+----+-----+---------------------------|
| hp | 22 | 22 | 22 | | | | |
| ac | 16 | 18 | 13 | | 5 | | 22hp → AC13 (Δ=18-13=5) |
|-----+------+------+-------+-----+----+-----+---------------------------|
| dpr | 17 | 17 | | 17 | | | |
| att | 4 | 4 | | | | | |
| dc | 11 | 11 | | 13 | -2 | | 17dpr → DC13 (Δ=11-13=-2) |
|-----+------+------+-------+-----+----+-----+---------------------------|
| dCR | | | 0.125 | | 2 | 2.0 | |
| oCR | | | | 2 | -1 | 1.0 | |
| CR | 1 | | | | | 1.5 | |
\-----+------+------+-------+-----+----+-----+---------------------------/
The example on DMG-275 makes it clear they are rounding average CRs to the nearest integer (2.5 becomes 3 in the example), so an average CR of 1.5 should become 2 (which does NOT match the CR 1 reported in the MM). That said, these situations where a CR is midway between integers is obviously ambiguous ... a CR of 1.5 can probably reasonably be interpreted as either 1 or 2.