When a druid wild shapes, what is the DC of abilities?

Question

Under the polymorph rules

The DC for any of these abilities equals your DC for the polymorph spell used to change you into that form.

The druids wild shape ability

At 4th level, a druid gains the ability to turn herself into any small or Medium animal and back again once per day. Her options for new forms include all creatures with the animal type. This ability functions like the beast shape I spell, except as noted here. The effect lasts for 1 hour per druid level, or until she changes back. Changing form (to animal or back) is a standard action and doesn’t provoke an attack of opportunity. The form chosen must be that of an animal the druid is familiar with.

And as a druid progresses in levels, more options are added than just beast shape 1.

However no where in the wild shape description does it mention what I should be using for the DC's of abilities. As a clear example lets take elemental body 1. I become a small air elemental which has the whirlwind ability. Now the small air elemental whirlwind is based on 10 + 1/2 HD + str mod, so in this case is DC 12.

However, the polymorph rules indicate that it should be based off the spell, except that its supernatural (SU). So if it was being based off of a spell, BS1 is a 3rd level spell, so DC should be 10+3+4=17 (I assumed our druid in question has an 18 for wis). Now DC 17 is pretty good.

However, what happens at higher levels (assuming I am staying as a small air elemental)? Does the DC change each time I gain access to a more powerful version? Thankfully it seems that Beast Shape, Elemental Body, and Plant Shape are all accessed at the same level, so BS1 is 3rd and accessed at 4th druid level, BS2 EB1 are 4th and accessed at 6th druid level, and so on so the DC's are equal at each level and dont encounter mismatches.

• Level 4 - DC 17
• Level 6 - DC 18
• Level 8 - DC 19

Answer 1

You always use the DC of the spell, unless said otherwise.

You don't have to recalculate your con bonus, calculate your HD or anything, simply use the spell save DC for any abilities that require a saving throw.

From Transmutation (Polymorph):

Each polymorph spell allows you to assume the form of a creature of a specific type, granting you a number of bonuses to your ability scores and a bonus to your natural armor. In addition, each polymorph spell can grant you a number of other benefits, including movement types, resistances, and senses. If the form you choose grants these benefits, or a greater ability of the same type, you gain the listed benefit. If the form grants a lesser ability of the same type, you gain the lesser ability instead. Your base speed changes to match that of the form you assume. If the form grants a swim or burrow speed, you maintain the ability to breathe if you are swimming or burrowing. The DC for any of these abilities equals your DC for the polymorph spell used to change you into that form.

Reading Elemental Body, we have the following:

When you cast this spell, you can assume the form of a Small air elemental, Small earth elemental, Small fire elemental, or Small water elemental. The abilities you gain depend upon the type of elemental into which you change. Elemental abilities based on size, such as burn, vortex, and whirlwind, use the size of the elemental you transform into to determine their effect.

Air elemental: If the form you take is that of a Small air elemental, you gain a +2 size bonus to your Dexterity and a +2 natural armor bonus. You also gain fly 60 feet (perfect), darkvision 60 feet, and the ability to create a whirlwind.

As we can see, there is nothing replacing the more general text from the Polymorph subschool. Meaning that we use the DC of the spell used to assume the elemental form.

This can be seen on other spells, like Form of the Dragon's Frightful Presence ("DC equal to the DC for this spell").