Inner Planes
There are 6 Inner Planes:
Earth, Fire, Air and Water are the 4 traditional elements and they are joined by Positive and Negative planes to make the 6.
Earth is opposite to Fire Air is opposite to Water Positive is opposite to Negative
Therefore, although balance is a combination of all 6, it can also be considered in pairs. For example, if Earth and Fire are both equally weak then that is less destabilising than if Earth alone is weakened.
The Inner Planes are critical to balance in the multiverse. They are not aligned (law/chaos, good/evil) but are simply a reflection of the pure element. This is particularly important for the negative and positive planes, which we intuitively but incorrectly link to evil and good respectively.
The 4 Elemental Planes are linked to Rings
All 6 Inner Planes are linked to [Crowns]
All 6 Inner Planes are linked to [Dragons]