Advancing Creatures by type

[kramis]

I'm having a little trouble with advancing creatures by size and type. Mainly with setting the new DC for special abilities. The ones listed in the beginning of the MM are easy since they give you the formulae, and it seems that most things are half HD plus Cha bonus. However, some things are obviously not and then I get stuck.

For example, the special attacks from a Chaos Beast, I can't see how they came up with the DC's and so I'm not sure how they change if the creatures gets more HD (if they do at all).

Anyone got any answers?

 

[Urbannen]

The DCs of the Chaos Beast's special attacks are based on its Consititution. The formula is 10 + 1/2 HD (4) + Con modifier (1) = 15. Somewhere in Savage Species it talks about determining the DCs of special attacks. Essentially any attack originating in the creature's body, such as poison or hideous, touch-induced transformations are based on Con.

The DCs increase by 1 for every two additional HD and by 2 when the creature increases to Large size and gains +4 Con.