Circle

The Eight Circles of Magic are the system used in Britannia to sort the spells of magic according to difficulty and mana drain.

Description
The system of the eight circles of magic was developed by the mages of Britannia some time before Ultima V, in order to bring order into the list of magic spells, which up to then had been pretty chaotic and without much of a system.

They decided after long research of the workings of magic on a system where the spells were divided into eight circles of ascending difficulty. The more experienced the mage is, the higher the circle he or she can access. This is also reflected in in the mana cost, with is always equal to the number of the circle the spell is located in.

The system was not chosen by chance. These eight circles correspond with the ethereal waves, which are made up of eight rings or circles of ascending power. Each circle is one of eight swirling vortices, all spinning one within another and expanding out through the universe in the Ethereal Void. Unlike what a non-mage might think, the higher cicles are the inner ones, which are smaller and therefore more difficult to reach. Only master mages can hope to manage and access the 8th circle, which is an exclusive level, as hinted at by Xiao in Ultima VI.

Outside of this system stand the linear spells, which are part of no ring and therefore can be accessed without any mana cost at all, needing only a certain amount of intelligence to be used.

Note however, that the system of eight circles is restricted to Britannia.

On the Serpent Isle with its different connection to the universe, magic actually has nine circles of magic, but no linear spells. It is unknown why exactly this is the case, as the chaotic nature of the ether is a mystery still in the process of being discovered.

Gameplay
In gameplay mechanics:
 * The level of the caster determines which is the highest accessable level. For example: level 4 = maximum circle is the 4th.
 * The mana cost is equal to the level, i.e. circle 4 spell = cost of 4 mana points.

In the Ultima Underworld games, the spells are still divided into eight circles, but do not correspond with the levels, of which there are 15.

In Ultima VII Part Two, the system is expended to 9 circles by just making it more challenging to reach the ninth level.