Magic gems are condensed magic energy and seven out of the eight paths of magic has gems while Blood magic has Blood Slaves. Magic gems are used to fuel rituals, powerful battle spells and in forging magic items. Magi can also expend a great number of gems of appropriate type so as to gain a permanent increased level in magic (called Empowering).
All battlefield spells have some kind of path requirement to cast. In addition, some battlefield spells also require the expenditure of gems to cast. Further, a mage in combat that has a gem that is of same type as one of his magic picks gets a +1 bonus to that path. For example, a Nature 1 mage with one Nature gem would count as a Nature 2 mage while casting a spell. Such a gem is consumed during the casting. Only the first such gem per cast grants a path bonus, so a Nature 1 mage with 2 nature gems still only counts as a Nature 2 mage.
Magi can also expend gems to reduce battle fatigue. For example, if X extra gems are consumed during casting, fatigue from the casting is reduced to 1/(X+1) of normal. Battlefield spells which cause at least 100 fatigue all require the use of enough gems so as to reduce casting fatigue below 100 (or need to be cast in a Communion, so the fatigue is shared between multiple magi).
Tip: Since magi tend to spend any available extra gems even on unscripted spells, it can be helpful to just give a mage only enough gems to properly cast their scripted spells. Give a stealthy scout a stockpile of gems and have him tag along with the army in stealth mode. After the battle, distribute gems from the scout to any magi in need for the coming turn.
Through empowerment, gems can also be used to bestow your commanders with a new magic path or increase a existing one. You need gems corresponding to the specific path and the cost is the new level times 15 or 50 for the first level.
Empowerment can only take place at a lab, and it takes a turn. So it must be balanced against not performing another action. Increasing the magic path of your pretender god does not increase your bless level.
Each level of magic adds +1 to research in addition to the effects of Magic or Drain scales. This is true for magic items that boost your magic paths, as well as empowerment. Some commanders such as Sages come with additional increased research ability or have research magically affected by scales such as Ulm's Smiths.
While the vast majority of sites generate one or more gems per turn, the following items, spells and commanders also generate gems.
The presence of these forgable items in-game generally leads to late-game "gem factories" where players can generate literally hundreds of extra gems/turn. Not only does this make for extreme abuse of globals- and summons-mechanics, but it entails massive amounts of tedious micromanagement to gather all the gems each turn from your commanders. For that reason, in competitive MP games, they have been eliminated from such popular mods as CBM.
- Fever Fetish
- (Const-2 F1N1) diseases wielder and has chance to generate 1 Fire Gem per turn as follows:
- - 25% chance to bring a gem when its wielder has max HP
- - 50% chance when wielder has 1 HP less than max
- - 75% chance with 2 HP less than max
- - 100% chance with 3 or more HP less then max
- Note: Neither shapechangers nor undead ever die of disease, but the fetish still works on them as listed above. Regeneration halts the loss of hp due to disease.
- Clam of Pearls
- (Const-2 W3N1) generates 1 Astral Pearl per turn.
- Blood Stone
- (Const-4 B3E2) +1E and generates 1 Earth Gem per turn.
- Ruby Eye
- (Const-8 F3) generates 1 Water Gem per turn.
Mother Oak (Alt-5 N5) Costs 50 N gems, generates 10 N gems/turn
Gale Gate (Thaum-8 A5) Costs 60 A gems, generates 20 A gems/turn
Maelstrom (Evoc-8 W6) Costs 80 W gems, generates 15 W, 5S, 3A, 1E, 1D, 1F, 1N gems/turn
Earth Blood Deep Well (Ench-7 E6) Costs 80 E gems, generates 20 E gems/turn
Eternal Pyre (Ench-6 F6) Costs 80 F gems, generates 20 F gems/turn
Well of Misery (Conj-8 D6) Costs 80 D gems, generates 21 D gems/turn and increases tax revenue everywhere by 10%
Stellar Focus (Ench-7 S5) Costs 30 S gems, generates 5 S gems/turn
Wish (Alt-9 S9) Costs 100 S gems. Can wish for 25 gems of all types (no blood slaves) or 250 blood slaves
Arcane Nexus (Ench-9 S8) Costs 150 S gems. Half of all gems used to cast spells and forge magic items are collected by the owner of this enchantment.
- Sea King 1W gem/turn. (Conj-6 W3) Comes with Sea King's Court
- Barathrus 1E gem/turn. (Conj-8 E5) One of the possible Kings of Elemental Earth
- Mother of Rivers 2W gems/turn
- Great Enchantress 1S gem/turn
- Arch Druid 1N gem/turn
- Lady of Springs 2W gems/turn