CR Adjustment for "Casts as an X-level Y"

[appending_doom]

For creatures that have in their entry "casts spells as an X-level Y" (Planetar, Rakshasa, Dragon), is there a good metric for determining how much of their CR is accounted for by that ability?

The more direct question is how much their CR goes down if you remove the ability.

Thanks for any thoughts!

[ericgrau]

I don't think there is a flat number you can add to the CR, because as you get to higher and higher levels low level casting becomes more and more obsolete. Likewise even if all of the creature's other abilities are weak, X level casting by itself will be something useful. I'd say his CR cannot be lower X-2 or so 95% of the time, maybe X-4 at the lowest. For beefier monsters with low level casting, consider how much it benefits him, if at all. A few buffs aren't likely to give him more than a 1 or 2 CR increase, assuming they're useful at all.

[Glimbur]

Counterpoint: swift action spells on a melee monster, or other monster which didn't have anything to do with its swift actions before, are nice. The scariest example I can think of is third level wizard casting on, say, a Hecatoncheires so that it can cast Wraithstrike and make its 100 attacks as touch attacks. Only third level casting means he doesn't have a lot of these to throw around, and each only lasts one round, but it is significant.

[Runestar]

For dragons, the xorvintaal template in MM5 implies that their spellcasting is worth ~ +1cr every 2 age categories (though some inconsistencies exist, the white dragon doesn't get spellcasting at young adult).

This is also consistent if you compare the pyroclastic dragon in draconomicon with the red dragon, the former has no spellcasting, is otherwise statistically identical, and 5cr lower.

As for the rest, I suppose you have to compare their existing stats with the next best alternatively. The raksasha would be fairly weak without its spellcasting, and will likely take the biggest hit.

The planetar can still stuffice as a decent beatstick. Also, if it retains its SLAs, then the loss of its clerical spellcasting may not result in a significant decrease in cr (you already don't have enough rounds to cast spells and use SLAs).

[Xefas]

Counterpoint: swift action spells on a melee monster, or other monster which didn't have anything to do with its swift actions before, are nice. The scariest example I can think of is third level wizard casting on, say, a Hecatoncheires so that it can cast Wraithstrike and make its 100 attacks as touch attacks. Only third level casting means he doesn't have a lot of these to throw around, and each only lasts one round, but it is significant.

Actually, I don't think I'd increase ol' Hector's CR for giving him 3 wizard levels, seeing as how I still don't think he'd be fit for CR 57.

Maybe switching his feats for stuff that doesn't suck would help. Weapon Focus (Boulder)? Really, Hector? Really?

[Runestar]

Actually, I don't think I'd increase ol' Hector's CR for giving him 3 wizard levels, seeing as how I still don't think he'd be fit for CR 57.

Maybe switching his feats for stuff that doesn't suck would help. Weapon Focus (Boulder)? Really, Hector? Really?

That is more the problem with his cr being inaccurate to begin with (a common 3e problem, where the designers didn't really understand the impact of certain abilities, or the lack thereof), and less so the usefulness of lower lv spellcasting.

Also, creatures can use their innate spellcasting to fuel abilities such as arcane strike. A dragon with 1 lv of sorc and that spellshield ACF in dungeonscape can sac a 9th lv spell as an immediate action to prevent up to 45 damage each round, dramatically extending its longevity.

So it is not just spellcasting, it is all the various abilities that interact with it which make it so useful.

[appending_doom]

For dragons, the xorvintaal template in MM5 implies that their spellcasting is worth ~ +1cr every 2 age categories (though some inconsistencies exist, the white dragon doesn't get spellcasting at young adult).

This is also consistent if you compare the pyroclastic dragon in draconomicon with the red dragon, the former has no spellcasting, is otherwise statistically identical, and 5cr lower.

As for the rest, I suppose you have to compare their existing stats with the next best alternatively. The raksasha would be fairly weak without its spellcasting, and will likely take the biggest hit.

The planetar can still stuffice as a decent beatstick. Also, if it retains its SLAs, then the loss of its clerical spellcasting may not result in a significant decrease in cr (you already don't have enough rounds to cast spells and use SLAs).

I suspected it might come down to something like this. A rakshasa might get knocked down to being an advanced doppleganger with spell resistance, but a dragon is still a giant fire-breathing lizard with spell-like abilities, and a solar can still kill anything in existence with one shot.

Of course, the DMG suggests an alternative suggestion. As an expert has -1 CR from a wizard of the same level, the subtraction of spellcasting should never remove more than 1 CR from a creature.

...

Sometimes I hate this game.

[Runestar]

I suspected it might come down to something like this. A rakshasa might get knocked down to being an advanced doppleganger with spell resistance, but a dragon is still a giant fire-breathing lizard with spell-like abilities, and a solar can still kill anything in existence with one shot.

Spellcasting actually does a lot to augment a dragon's combat prowess. You have arcane strike, the metabreath spells, personal buffs, arcane spellsurge, swift/immediate action spells and contingencies. -5cr for a great wyrm red dragon actually seems reasonable.

Of course, the DMG suggests an alternative suggestion. As an expert has -1 CR from a wizard of the same level, the subtraction of spellcasting should never remove more than 1 CR from a creature.

And as shown in city of the spider queen, is grossly inaccurate.