Are monster spell lists set in stone?

[DaLucaray]

Do monsters that cast spells as spontaneous casters or as spells-known casters (I don't know if there are any of those, actually) vary their spell lists from individual to individual? Or does every Aranea know Invisibility and Mirror Image as their level 2 spells? I would assume no, but I scoured my Bestiary and have not found any indication one way or the other.

In fairness this is more a curiosity question, as I plan to ave monsters knowing whatever is useful to them, but it seems odd to me that I can't find any indication that that's how it should be played.

[PossibleCabbage]

Bestiary monsters are "a typical member of whatever class". If a GM has a reason to include a variant one, they can. A bestiary is really mostly a GM resource as it saves you the trouble of filling the entire cast with bespoke antagonists (and is also a world-building document.)

[avr]

Wow, that's a lot of duplicate threads.

Yes, those are suggested not required spells.

Edit: Especially for monsters with prepared (such as cleric) spellcasting, who can change their spell loadout overnight.

[Zhayne]

Absolutely nothing in a monster's spell block is set in stone. Feats, ability scores, everything can be changed at the GM's discretion.

[Brew Bird]

If a creature casts spells "as a particular class", then they usually have the same freedom in spell selection that that class does. Dragons can select whichever sorcerer spells they want, for example.

[Vidmaster7]

If I ask 15 times I can be really sure.

[wraithstrike]

The game assumes that the stock(book version) of the monsters are what the players will run into, but it's not a hard rule that the GM is limited to what is printed in the book.
Since GM's are allowed to add classes level and templates I see no reason why they can't change spells or SLA's.

If I run a dragon I often change the spells they know since they cast as sorcerers.

[Dasrak]

Just like feats, I would say the GM can swap them out as desired. From a strict RAW perspective, it's not like monsters can't make use of the retraining rules ;-)

[toastedamphibian]

A creatures spells known is just what those creatures generally know. If your making an individual, then pick any spells it could legally take. I'm quite certain the given spells are just there so people don't have to pull their hair out and pick spells for an 8th level sorcerer everytime they want a random Naga or whatever.

Changing SLA's is a bit of a different story, those are usually set by race.

[ericthecleric]

There are lots of examples of monsters with spellcasting in Adventure Path books having different spells.

[tonyz]

I always update the spell lists for whatever this particular monster is likely to do, or what they might know about the players, or what I think makes sense.

Also note, it's often worthwhile to see if later-published spells are the sort of thing that an earlier-published monster might have reasonably had.

[Saldiven]

From the Bestiary:

"While each monster is a unique creature, many possess similar special attacks, defenses, and qualities."

The first clause of this sentence, to me, indicates that there is no reason that every individual of a specific type of monster has to be identical to the rest.

[DungeonmasterCal]

I've done it for years. I see no reason game-wise where this would be a bad idea.

[Zhayne]

Especially when some monsters get lame feats like Alertness ...

[toastedamphibian]

If you pick really good feats or spells, you might want to consider bumping them up a cr or two... Almost killed a 4th level pc once with a pair of house cats who had Burning Brand martial maneuver from a feat. (3.5 Book of Nine Swords)

[ryric]

Overly pedantic reply: No, the spell lists are written on paper or displayed on screens.

I run it as the "generic" version of the critter has the listed spells. Otherwise, summons become exponentially more powerful as you can pick a summoned monster with exactly the spell list you want. Heck no to that.

SLAs innate to race don't change for me. Actual caster spell lists can be altered to make a unique creature.