2 variant rules, from Elementalism to Extreme Good and Evil.
Elementalism · Extreme Good and Evil
Elementalism
The world is a reflection of the Elemental Planes. Fire blazes in its core, cradled and calmed in a bed of Earth. Water brings the parched soil relief, strengthening as it soothes. All this is encapsulated by Air, which breathes life into the world. Elementalism is the belief these four elements are the components used to create all matter. Thus, magic is simply the manipulation of the four elements. Understanding these elements is the essence of elementalism.
Druidic Orders
Elementalists eschew traditional magical divisions in favor of the elemental quaternity and rarely attempt a formal education. Instead, they travel Falavririak, learning from the environment and elemental masters. These sojourns are referred to as pilgrimages, and the lessons learned along the way are called exposures or forms.
Druids are among the most well-known elemental masters, capable of harnessing the power of nature that exists below a mountain or flows through an ocean. Although some act as wardens to the world as a whole, most specialize into one of three orders that revere individual elements. Within these orders, as well as the storm order (Core Rulebook 132) that focuses on air, a sizable contingent of druids devote themselves fully to elemental magic, choosing the elementalist class archetype. However, just as many druids in these orders access magic from the primal spell list normally, believing that they can still take a wider view of nature through the lens of their element.
Elementalist druids are more common in regions with strong traditions involving the cycle of elements, such as Brafalaisias.
You can find the Flame Order, Stone Order and Wave Order on the class page.
Focus Spells
These elemental focus spells are available to druids of the flame, stone, and wave orders and to characters with the elementalist class archetype.
You can find the new focus spells on the spells page.
Monk Stances
Monks manipulate the elements within themselves to manifest magic. Mountain Stance and Wild Winds Initiate from the Core Rulebook provide earth and air.
You can find the new monk feats on the feats page.
Elementalist
You can find the Elementalist class archetype on the archetypes page.
Secrets of Magic, page 198.
Extreme Good and Evil
In this variant, some creatures exemplify the concepts of extreme good and evil by their very nature. Only fiends, celestials, and other residents of aligned Outer Sphere planes have an alignment. Remove most alignment restrictions—such as the cleric and champion restrictions—but not ones related to those extraplanar creatures. Replace the removed restrictions with appropriate anathema if necessary.
Gamemastery Guide, page 184.