Now, re the magic users…
you can divide the magic in Empire into two categories:
Personal magic, and Ritual magic.
The Personal magic is something you’re likely familiar with from some D&D settings: you have a store of personal mana, it refreshes daily (or with help), and you spend some of this to cast spells. Spells include offensive spells, such as REPEL, and non-combat ones such as HEAL. They may take a few seconds of roleplaying (often chanting or singing or praying or whatever) to cast.
The Ritual Magic is, functionally, pestering the magical realms and paying them crystallised mana in exchange for favours. This can be as small as (This guy gets an extra hit point or two) or as big as (On the campaign map, this army is reinforced by 3000 Faerie Knights).
The Realms are Day, Night, Spring, Summer, Autumn, Winter. Each has a different flavour and style, their own bunch of powerful beings (known as Eternals. You may find it helps to think of them as Elemental Lords? They are NOT gods). Each has their own lineage (a human physically affected by the realm of Spring may exhibit Briar lineage, for instance, and look a little bit like a dryad). And each has their own specific lore for dealing with them.
So a mage with Summer Lore 2 (bought in levels, for character points, and buffed by various things), can cast Summer Rituals up to magnitude 2. Note that’s only Summer, none of the others. You can buy multiples, but specialising is likely a good start. He might have a single ritual Mastered (“I am an expert in this one…”) and that allows him to cast it at magnitude 4.
The ritualists tend to be grouped together to cast big rituals with as many buffs as possible. This is a numbers and organisation game. If you’ve played D&D, you know this can be damn tricky…
"Now we’re all bound into this one coven so we can cast this together. There are 6 of us, we all have Summer Lore 2. We’re standing in the Magic Circle (aka Regio) that grants us all +1 effective Lore. So that’s Summer Lore 3. And we all have this one mastered, so it’s at magnitude 6. So that’s 6 x 6 for a 36 magnitude ability, the ritual is magitude 35… we can do this! We now need to practise this, as it’ll take a while, find a huge pile of crystallised mana, and get to the Regio for our slot in time… "
…okay, got carried away there.
Anyway, it looks fiendishly complicated, it’s not. Would you like some links to relevant bits of the wiki?
Have a look around, and feel free to ask questions on anything!