So, in a previous post I made here, I mentioned I'm making a Campaign Setting, using the Pathfinder Rules as a base, based on the Mana Series games. Stuff like Secret of Mana, Legend of Mana, Sword of Mana and so on.
I came upon a road block, in the world of Fa'Diel, where most of the Mana Series games take place, the balance of magic is kept by several elements. Each element also has a specific elemental spirit.
Fire - Salamander
Water - Undine
Earth - Gnome
Wind - Jinn
Wood/Nature - Dryad
Moon/Celestial - Luna
Light - Wisp
Dark - Shade
These Elemental Spirits are the children of the Goddess of Mana, the only real deity in the game.
How the games normally go:
Fire beats Earth
Earth beats Wind
Wind beats Water
Water beats Fire
Wood and Moon are both strong and weak against eachother.
Light and Dark are both strong and weak against eachother.
Clerics/other Divine Users are limited to one Goddess.
Now, what I'm wondering is how to translate this into Pathfinder.
Simplest way to represent this in game mechanics is by varying saving throw DCs.
Pick your creatures that will be "aligned" with a certain element, and say that all creature/spellcasters/etc that are aligned have a -2 penalty to saving throws from the element they are weak against, while getting a +2 on saving throws against spells they are strong against.
So say you have a Fire Elemental. When someone targets him with a Water spell with a save DC of 15, for him it's 17, but when someone else uses an Earth spell, the DC is 13 instead of 15.
The +/- amount can be changed depending on how significant you want this different to be.