I realize the topic of calculating the CR of a monster with class levels has been covered quite extensively on the boards, but I have a situation that I haven't seen broached yet.
According to the Bestiary, when adding non-key classes, the CR goes up 1 for every 2 non-key levels added, until the number of levels added equals or exceeds the creature's original CR. (At which point, the remaining levels are treated as "key" levels.)
My question is in two parts:
1) What if I'm adding more than one class?
Let's take a treant for example (CR 8). If I add 6 levels of druid and then 6 levels of bard, I've just added 12 total levels in non-key classes.
If I was adding 12 levels in one class, that would make this CR 16. However, neither class's class level exceeds the original CR of the treant. Does these mean none of the levels count as key? (Which would make this a CR 14.)
Total levels exceeding original CR vs. each class's class level exceeding the original CR. Which is it? The wording in the Bestiary (p.297) is unclear.
2) Same example...treant, CR 8... but this time adding only 3 levels of druid and 3 levels of bard. Is the CR 10 or 11?
Having an odd level hanging there, does it count as a half CR, which can be added to the other classes hanging half CR, or is it just rounded down in each case?
The wording in the Bestiary (p.297) is that you add 1 CR for every 2 levels added. This COULD be interpreted as 1/2 CR for every level, but unfortunately, that's not what it says.
(For this part of the question, I am leaning towards the half CRs NOT counting, as the original wording from 3.5 DID say 1/2 CR per level.)
Thanks for your consideration,
Taffer
It would take a lot of work, time, and effort to try to use that table to extrapolate the information I'm looking for. I was rather hoping someone already had the answer.
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Taffer
There's nothing to extrapolate. You already have the information, you just compare it to the chart.
I believe I've heard the Designers say in the past that creating your own encounter is part art, part science. I wouldn't try to pin down the exact CR in decimal places if I were you.
You seem to be missing the point of my question. I already know about the table. I know how to use the table. I've used it on several occasions.
I am asking for clarification of the formula that was put in the Bestiary. I know it's not perfect, I know I'll have to refer to the table sometimes, but I want to know what their intention was with the formula.
1. In my opinion, it would be total levels exceeding the original CR. So in the given example, you'd get a total of 8 levels at a discount, but the remaining 4 at full price.
2. Again in my opinion, it should be 11. Otherwise you're essentially trying to "cheat" the system by having 2 1/2-increases where neither counts.
Also, adding 1/2 CR per level is mathematically the same thing as increasing CR by 1 per 2 levels; in both systems, my answer would be the same. Except for the part where 3.5 worked off the creature's HD rather than CR, which could make for some rather unpleasant results.