Hi folks, new guy here.
In the enthusiasm of rediscovering world building through Pathfinder after a long semi-retirement from the hobby, I wanna do something special for my next project. It's a bit specific so please bear with me.
In this campaign setting true dragons aren't tied to standardized alignments or terrain preferences and they are more or less equally powerful between their various multicolored flavours. Because fluff.
I will also add 2 metallic, 2 chromatic and 7 mineral (rock dragons? Oh yeah!) new dudes, change the appearance of everyone back to the iconic Lockwood stile where possible, (others will have awesome images stol... ehm, borrowed from other illustrators, mainly Kerem Beyit)and get ridden of every other true dragon.
Maybe I will even think something for minor ones.
In order to accomplish this I decided to pick the Red one as a base so to ensure a big bad progression of power.
Looking at the upper right table on page 98 of the bestiary (I have the 3rd printing) I see that the "Special Abilities" column needs a heavy cut: everything except the spell-like abilities, DR, SR and frightful presence needs to go.
This leaves me with six spell-like abilities (level 0, 2, 3, 4, 6 and 8. In order)and the aforementioned "all dragons have them" stuff.
I would like to change detect magic to a supernatural permanent ability for every true dragon and keep the rest only for the red one: the other dragons will have suitable spells of the same level that I will choose later.
I also want to give all true dragons the water breathing Ex ability to ensure that everyone has the options to get one of those cozy underwater tropical lairs in their retirement years. (aka they can lair everywhere they damn well please)
Everything else I think could easily stay the way it is keeping the red dragon stats from wyrmling to great wyrm.
For the breath weapon everyone will have his own (either a line or cone of energy, no fancy mumbo jumbos) and obviously each kind will have it's own corresponding energy immunity.
So here's the question: how do I set a challenge rating for this variant? They lose something and gain less, but it doesn't strike me as a big decrease in power.
There's some official way to establish this in some book I don't own?
Ok, I'll admit it, it's my fault beacuse I don't have a group of players to pit against my creations, but surely the guidelines in the bestiary don't help me in the slightest.
Oh, and just to satisfy a curiosity... If I where to go further and strip dragons of their sorcerer spells how much would affect CR?
I found in these message boards topics similar to my own, but not quite the same. Plus they where never answered properly...
Thank you to everyone who will be so kind to respond and sorry for the text wall, I'm sure is full of typos and bad grammar.
D.