I'm trying to create a custom werecreature for my PCs to battle, a wererat; but I'm running into a discrepancy. By the rules of building werecreatures, under Curse of the Werecreature: "Saving Throw Fortitude DC is the standard DC for the werecreature's new level – 1."
The DCs for Curse of the Werecreature in existing werecreatures are all over the place.
The Werebat, Wereboar, & Werecrocodile all use a Level 2 moderate DC 15. The Wererat curse uses a Level 2 high DC of 18
The Werewolf uses a DC of 19, which would fit a Level 3 high DC 20-1
The Weretiger uses a level 4 moderate DC 18. The Werebear uses a DC of 22, which doesn't fit any of these formula as far as I can see.
Does Standard DC mean Moderate DC or does it mean whichever I prefer? Is there a reason the wererat and werewolf are high DC? And only Werewolf uses the DC -1.
What's with Werebears? High DC would be 21, and moderate would be 18. It seems to be high +1.
If I'm making a wererat midboss, should I base the DC on a wererat of the creature level (like DC 21 for a Creature 4 wererat,) or creature level -1 (DC 19) Or moderate DC -1 (DC 17.)
Is this one of those things where I should still just eyeball the DC?
Standerd DC is just a reference to point to the original DC before apply the template modification. If your are build your own monster based in Building Creatures guide you will build the monster as normal using the scale that you prefer and then will apply the were-creature template over it.
It's impossible for us to know the exact thought that went into published Bestiary creatures.
The guidelines for the DC basically tell you to look at the DCs for a creature of its new CR and give it an adjustment.
There's always a degree of just making it up as you go. Don't try to look at existing creatures for some sort of scientific exact method or logic, because they weren't made that way. It's not like someone wrote a NPC generating excel spreadsheet were you choose a CR and generate all the monsters stats.