Reducing All Spell DC's
 

I need to reduce all players Spell DC's by 12. I found the adjustment to add a DC modification to a spell, but I was hoping there was an adjustment or a set of adjustments that could apply to to all so I don't have to add one for every single spell each character knows.

The All Checks does seem to cover it, but obviously it is applying to every other check.

If anyone has already done this, or know of a setting I could use to accomplish it, I would appreciate it immensely!

Thank you!