How do I calculate Challenge Ratings?

[Xanos]

I know this is a bit of a "Duh, stupid" question, but I can't seem to find it anywhere.
So, how do I calculate challenge ratings? For example, a 7th Level Drow Wizard?

[psychoticbarber]

It's a wizard, so, nigh-infinite? :smalltongue: Sorry, I'm not good at this kind of thing.

[Saph]

Officially? 7 for having seven levels in a PC class, then add 2 for being a Drow. So, CR 9.

However, Challenge Ratings are more of an estimation than a set of strict rules, and often a monster will be tougher or weaker than its CR indicates. In this case, being a Drow doesn't give enough benefits to be worth 2 points to CR, so I'd drop it down one to CR 8.

Then you need to take into account how the PCs will be facing him. Will he be caught by surprise? Much weaker, maybe as little as CR 6. Will he be prepared with several buff spells cast already? More like CR 9.

Basically, just eyeball it. Estimating CRs is one of the skills DMs pick up from practise; you'll get the hang of it soon enough.

- Saph

[Xanos]

Doh >_<. That was just silly

Edit: Thank you, I thought as much. It was just the formular, which is just levels + LA? (+ Racial HD?)

[Saph]

Thank you, I thought as much. It was just the formular, which is just levels + LA? (+ Racial HD?)

No, Racial HD's factored into the original monster's CR. For a monster with Racial HD, the CR is (Normal CR) + (PC Levels)*.

- Saph

*Assuming they're associated rather than nonassociated, but let's not get into that.

[Jasdoif]

Officially? 7 for having seven levels in a PC class, then add 2 for being a Drow. So, CR 9.Normally this would be the case; but Drow are weird and have a CR formula given in their entry.
Drow with levels in NPC classes have a CR equal to their character level. Drow with levels in PC classes have a CR equal to their character level +1.Wizard is a PC class, so a Drow Wizard 7 has a CR of 8.

Come to think of it...where'd you get 2 for being Drow? The listed 1st-level warrior's CR is 1, not 2.

[Saph]

Ah, didn't check that. Well, I guessed CR 8 anyway. :)

It's worth bearing in mind, though, that how tough a wizard is to fight is based almost completely on how much preparation time he has beforehand. If he has no spells up when the party bursts through the door? He'll be toast with a single charge attack. If he has armour, shield, flight, and invisibility spells running? Much much harder.

- Saph