Level Up (A5E) Monstrous Menagerie - Creature Creation - Spellcasting abilities impact

[bkthomson]

I'm working my way through creating a new creature (5e) following Appendix C guidelines. This creature has spellcasting abilities, and I'm not sure how that type of "ability" factors into the creature's design.

So, for example, I'll use the Abjurer Wizard spells
At will: dancing lights, mage hand, message, prestidigitation
2/day each: dispel magic, lightning bolt, mage armor
1/day each: arcane lock, banishment, globe of invulnerability, invisibility, wall of force

What would these do or impact the creature I'm designing, if anything at all?

 

[xiphumor]

I don't have a definitive answer, but the chromatic dragons in A5e all have spellcasting variants that don't impact CR (in theory). I would compare your ideas against them as a baseline.

 

[lichmaster]

I don't have a definitive answer, but the chromatic dragons in A5e all have spellcasting variants that don't impact CR (in theory). I would compare your ideas against them as a baseline.

I think spellcasting may not impact CR if the baseline CR is already relatively high: normally spellcasting costs one action, and high CR creatures may have standard attacks that are comparable to low/mid level spells.
But for a low/mid CR creature, spellcasting can substantially increase the offensive or defensive capabilities.

 

[Uni-the-Unicorn!]

I don’t recall what A5e uses for spell design; however, the 5e DMG has an expected damage by spell level table. That, in theory, should allow you to convert a non-damage spell to damage and use that to calculate CR. However, you have to be smart about it and not use it blindly.

 

[bkthomson]

I think spellcasting may not impact CR if the baseline CR is already relatively high: normally spellcasting costs one action, and high CR creatures may have standard attacks that are comparable to low/mid level spells.
But for a low/mid CR creature, spellcasting can substantially increase the offensive or defensive capabilities.

That is a good perspective that I had not taken into consideration. The creature I'm working on will be either CR 6/7 (The difference between the two is Hit Points and Average Damage per round.) I'm not settled on the spells or if I should include them, but this is what I have in mind for the stat block.

 

[Morrus]

I think a spell would only affect the CR if it were substantially better than an equivalent CR creature’s non-spell abilities.

 

[bkthomson]

I think a spell would only affect the CR if it were substantially better than an equivalent CR creature’s non-spell abilities.

Sorry to bother you, but I appreciate the response. Taking what you said in math terms, offensive spells would have to do at least a quarter or half more damage than the average per round to increase the CR?

 

[Morrus]

Sorry to bother you, but I appreciate the response. Taking what you said in math terms, offensive spells would have to do at least a quarter or half more damage than the average per round to increase the CR?

I wouldn’t want to quote figures. I’m not enough of an expert. @duneguy would be the one to ask — he’s the monster math guy and the author of the book!

 

[bkthomson]

I wouldn’t want to quote figures. I’m not enough of an expert. @duneguy would be the one to ask — he’s the monster math guy and the author of the book!

No problem! Thanks again for your input.

 

[Uni-the-Unicorn!]

FYI, you have calculated the average damage of the Thunder attack wrong. It should be 36 (8d8) thunder damage