Dragons and Practised Spellaster

[Erik Vale]

A thought occured to me with dragons when I was thinking about a dragon [monsterclass]/Other Class character, dragons also count as a sorcerer of 3/4 their HD [Well, some of them, but assume for ones that do], in this case, how would the Dragon levels interact with Practised Spellcaster (http://dndtools.eu/feats/complete-arcane--55/practiced-spellcaster--2231/) [Try and give RAW readings], particularly:
-Would it raise the effective sorcerer level to 3/4 level + 4 up to the dragons HD?
-Would it raise the dragons level for determining effective sorcerer level by 4 [up to HD]?

I'm expecting any rational GM would rule the later, but again, looking for a RAW ruling over a RAI or If I Was GMing answer.

[DeltaEmil]

It would gain 4 caster level for its sorcerer spellcasting ability, I'd guess, if it counts as a valid target for the feat.
So, point 1, but not 2.

[Nettlekid]

Well strict RAW, nothing would happen because it raises your CL for the chosen spellcasting CLASS, and the Dragon racial HD is not a class.
Apart from that it's kind of hard to say. When you're dealing with actual classes like Sorcerer and Wizard, it's easier to manage because CL and spells known/spells per day aren't actually linked, so a caster can have a higher CL but still be limited to lower level spells. Dragons seem to cast spells per day and have spells known as a Sorcerer of their CL, so it blends the two a little. I'd say a reasonable interpretation is to treat it like you would a class, in that if a Dragon who cast as a level 12 Sorcerer took the feat, it would have CL 16 for purposes of duration and range and other spell effects, but still only have the spells known and spells per day of a 12th level Sorcerer, just as a human Sorcerer 12/other 4 who took that feat would.

[tyckspoon]

A thought occured to me with dragons when I was thinking about a dragon [monsterclass]/Other Class character, dragons also count as a sorcerer of 3/4 their HD

I'm rather curious where you found this, as this is not a general rule AFAIK. RAW, you determine a dragon's effective sorcerer level by checking its Age Category, and then looking on the chart to see how much casting that particular Age and Color combination gets. HD is irrelevant except as it relates to Age (that is to say a 15 HD Juvenile Copper and a 16 HD Juvenile Copper both have 3rd level Sorcerer casting, because that's what Juvenile Coppers get.) Practiced Spellcaster then improves their caster level +4 over the number from the chart, to a limit of their HD (it will never hit this limit on any printed dragon I have ever seen, as dragon HD is usually double digits higher than their sorcerer level.)

Standard reminder: Practiced Spellcaster does not actually advance casting. All it does is increase caster level- although the example Juvenile Copper I mentioned would, with Practiced Spellcaster, make Spell Penetration checks and have the damage and durations of a 7th level caster, he still has the spells/day and spells known of a 3rd level Sorcerer.

[Erik Vale]

Like said in the OP, I was fiddling around with monster classes that grant spellcasting based on HD.

However, it looks like it lies in the not-valid target area for said feat.