Advancing Spell Like Abilities

[aeauseth]

Does anyone know where (or if) there are rules for advancing spell like abilities?

To make things a bit more clear I will use an example. A normal Dark Naga (http://www.d20srd.org/srd/monsters/naga.htm) has 9 Hit Dice and casts as a 7th level sorcerer. If you advanced the Dark Naga to 27 HD does it improve its sorcerer abilities?

Another example. A normal Djinni (http://www.d20srd.org/srd/monsters/genie.htm) has 7 Hit Dice and is considered a 20th level caster. If you advanced the Djinni to 21 hit dice does it improve its spell like abilities?

I think the answer to both examples is yes, but the rules for Improving Monsters (http://www.d20srd.org/srd/improvingMonsters.htm) does not provide any guidance for improving spell like abilities.

[DeltaEmil]

To make things a bit more clear I will use an example. A normal Dark Naga (http://www.d20srd.org/srd/monsters/naga.htm) has 9 Hit Dice and casts as a 7th level sorcerer. If you advanced the Dark Naga to 27 HD does it improve its sorcerer abilities?If you give the Dark Naga more aberration Hit Dice, then no, its sorcerer spellcasting ability do not increase. If you give the Dark Nage sorcerer levels (or levels in a prestige class which advances spellcasting), then its sorcerer spellcasting ability does increase.
However, only aberration HD do increase the Dark Naga's size. More levels in sorcerer (and prestige classes that improve spellcasting progression) do not increase the Dark Naga's size.

Another example. A normal Djinni (http://www.d20srd.org/srd/monsters/genie.htm) has 7 Hit Dice and is considered a 20th level caster. If you advanced the Djinni to 21 hit dice does it improve its spell like abilities?No. Hit Dice would only affect the caster level of a spell-like ability-using creature if it had no caster level defined in the first place. Aside from that, Hit Dice have no effect on how many spell-like abilities a creature might have. So a Djinn with 21 HD still has only a caster level of 20, and none of its spell-like abilities do change in any way.
However, a 21 HD Djinn would be huge, and quite a formidable warrior, because of its outsider HD.

[Deca4531]

I seem to remember a template a came across once upon a time, I think it was for an intelligent undead, that allowed you to gain more and better spells based on your total HD, but im afraid I cant say for sure what it was. another thing you might want to look at is the Warlock class since they work souly in SLA.

[DeltaEmil]

I seem to remember a template a came across once upon a time, I think it was for an intelligent undead, that allowed you to gain more and better spells based on your total HD, but im afraid I cant say for sure what it was. That would be the Spellstitched template found in Complete Arcane.

another thing you might want to look at is the Warlock class since they work souly in SLA.Levels in Warlock and Dragonfire Adept do not change the normal spell-like abilities of creatures like the Djinn, despite invocations being a sort of spell-like ability.

[Deca4531]

Levels in Warlock and Dragonfire Adept do not change the normal spell-like abilities of creatures like the Djinn, despite invocations being a sort of spell-like ability.

I know, I meant it more as a source of inspiration if the OP wanted to wing it.