[SIZE="4"]Magic Explained[/SIZE]
There are three arcane magic units, adepts can only cast level 1 spells, they upgrade to mages which can cast level 2 spells, and they upgrade to archmages which can cast level 3 spells. You can only have 4 archmages, and the spells they cast are generally very powerful. Only adepts can be built, in order to get mages or archmages you must upgrade. Arcane units gain a passive xp gain, like the priests of winter which means that over time they will gain levels and promotions, this is necessary as promotions are what unlock spells, and without them you have a crappy and expensive warrior. To upgrade to mages or archmages you need to reach a certain level of xp, so start building adepts as soon as you can if you want to get mages later!
Access to spells comes from mana nodes, which are unlocked by the second level arcane technologies(And also sorcery). If you have multiple copies of the same node then your arcane units can get free promotions. I have two Ice Nodes, so all of my adepts will gain Ice 1. If I had 3 ice nodes then all of my mages would get Summon Ice Elemental for free.
The four second level arcane technologies let you build different mana nodes, and each node gives your casters access to spell promotions, unlock different towers needed for the Tower of Mastery victory and often have a useful secondary effect. I've talked about them a little before but I probably need to do a more in depth analysis on the magic system, since it is what I'll be focussing on. The four different technologies are:
[SIZE="3"]Necromancy[/SIZE]
Caution:Slight chance of ending world
Necromancy controls the "evil" mana. In SP games they carry a diplo malus for use in many cases. They also have a lot of powerful effects. The four mana that come under necromancy are
Entropy. Entropy nodes make opponents heal slower in your territory. With a few entropy nodes controlled it actually has a noticeable impact on enemy forces, particularly ones without medic. Not one of the better secondary effects, but not one of the worst. It allows some good spells as well. Rust is the low level entropy spell and is one of the most useful in the game. What it does is remove metal promotions until units go to a forge. Very handy little spell, and I'll make sure to have a few adepts with that ability when I get an entropy node. The other spells are moderately good. In my opinion both are overshadowed by Ice spells though, so I won't be using them.
Shadow. Shadow sucks. It has no secondary effect. It has poor spells. I rarely if ever make use of it. I'll be getting a node off Sareln to build the tower and that is it.
Chaos. Chaos is fun. It doesn't really have a secondary effect to building it, but occasionally your units will spawn with mutations. It's spells are decent at all levels, and I'll be making a few chaos adepts to give my units dance of blades. I'm not going to be using the two higher level spells. Mutate can cause either good or bad effects, Wonder can be the most powerful spell in the game or it can screw up and actively cause you harm. Both are a good sideline for use by mages and archmages.. but I'm not going to use them in this game.
And finally the star player of Necromancy
Death. Death mana has no secondary effect, but is by far the best mana in the game. At first level it summons skeletons, which are handy disposable units to help in garrison duty, as mage bodyguards or just to mildly injure the foe before an assault. At second level is summon spectre. This spell is insanely good if you have focussed on building death mana nodes. As soon as I have the luxury to do so, I will use as many death mages as I can. Spectres are hypermobile, and with death affinity become hyper strong too. Seriously scary critters. The third level spell is summon wraith. A fairly good summon spell, which works well with the aforementioned spectres, the fear they induce can be used to push enemy stacks into open ground away from hills, where they will be carved up by spectres with ease. Death 3 also allows you to create liches, which mean that instead of the 4 archmage slots that you would ordinarily have, you can effectively have 8. Yowza.
The big achilles heel of Death Mana is life mana, although only partially. More on that later.
The tower of Necromancy is one of the better towers, but it heavily focusses you towards death magic. It gives you a free Death Mana(Nice) and makes all your Undead units strong(+1 str also very nice). If you aren't going to be using many death magic summons though.. it's pretty useless. Since I'm going to be using Ice Elementals for quite a while, this will be the last tower I build, and necromancy will be the last of the magic techs I research.
Necromancy also gives access to the Mokka's Cauldron wonder. Mokka is a frostling hero spawned by the Samhain ritual, so I'm a little curious what his cauldron is doing under this technology. It resurrects units killed in the city it is is built in as weak undead. I guess it could be useful for a border guarding city, but I've never really tried it.
[SIZE="3"]Alteration[/SIZE]
Because playing god is fun, and what is a god without the ability to mold flesh?
Alteration is a weird one. It is annoyingly high up on the great sage lightbulb list, making that specialist pretty useless until you have researched this. It gives access to only three mana instead of 4, but 4 mana are still required to build the tower. The tower itself doesn't actually help the mana associated with Alteration at all. However it gives access to two of the best mana in the game, and the tower is a pretty useful accompaniment to many strategies.
The three mana it gives access to are:
Enchantment. Enchantment has one of the best secondary functions, comparable only with mind or law as a non magic users node. Every node counts as a luxury resource, giving a free happy face. Not content with that it also gives access to three exceptional spells. At level one it gives enchanted blade, which is a 20% bonus to melee units. Essentially a free combat promotion. At level two it gives the flaming arrow spell, which gives archery units +1str, and is really awesome if you focussed that way(Ljosalfar, Amurites, I'm looking at you). At third level it gives access to Enchant Spellstaff, which essentially lets you save up a turn of spellcasting to be used when it is needed. Getting an extra archmage spell in can turn the course of a battle, so that one is nice.
Body. Body has a nice secondary function, increasing heal rate. Far more importantly however, it has some of the best general use spells available at its first two levels. Haste gives a bonus movement point to all units in a stack. At second level is the equally lovely regen spell. This is like a free march promotion for every unit in the stack(although it wears off after the unit is fully healed). Both of these only apply to "Living" units. Demons, angels, elementals, siege weapons, golems and undead do not gain this effect. Tough luck for the not alive I guess. At third level is flesh golem. This spell makes a frankensteins monster that can gain the abilities of units added to it. It's a lot of fun to piss around with in SP, making an unholy death machine that would make Eurabatres himself shudder in fear, but we're definitely not going to be doing that this game.
Free access to haste and regen(as well as spectres) is part of what makes vampires so insanely deadly. Although the incredibly easy experience gain also helps. Part of what makes centaurs good is their ability to cast haste naturally.
Nature. Nature has no secondary effect. It is a fairly underwhelming mana, first level is mostly junk that can be good situationally. The second level spell helps you if you're going for recon units, which I am not. The third level spell can fix crappy terrain, and is incredibly awesome in SP, when you can create a lush grassland over the desert. I don't need it, I have Temple of the Hand. Not going to be using the spells from this mana. It's another one I'll get from Sareln, build the tower, then not think about again.
The tower of alteration is really nice.. but not for helping alteration spells. It reduces enemy chance to resist spells by 20%. Spells like slow, blinding light, charm person, dominate person , entangle and a few others are all made better, and they're all already pretty good. I'm going to be building it third. After the tower of the elements. The non-alteration mana it requires is life.
[SIZE="3"]Elementalism[/SIZE]
Raw unfettered power
Elementalism gives access to Fire, Water, Air, Earth and sadly not ice. The tower is almost always awful, but I think in this game it may actually be pretty good. The mana in this category are.. I'd call them solid. Nothing awful, nothing insane. Only Earth has a secondary effect to owning nodes.
Water. Water is probably the worst of the 4 on this map. The first level spell is junk for me, but is normally a useful terraforming spell, turning desert into plains(It also counters fire 1). The second level is junk on this map(Water walk can be used to bring an attack from an unexpected angle, but only PB and Cull have worthwhile coastal cities. Against Iskender, Bob or Sareln I'd probably only take out fishing villages. Not worth the investment.). The summon spell is.. well it can be broken with a twincaster on Keelyn. It is one of the big reasons to be building the tower of the elements, as Water Elementals are made more than twice as good. I'm probably not going to be using it, but the water elemental is one of the better summons.
Fire. Fire is solid and dependable. Each spell has a function. You'll never be annoyed that a mage took a fire spell. Fire 1 sets forests on fire. A great screw you to the elves who absolutely need forests. Fire 2 creates a fireball. This is effectively a free catapult, it can either reduce city defences or attack units and cause collateral damage. Fire 3 gives you a Fire Elemental summon, which is a decently powerful unit, but more importantly causes heavy collateral damage. I don't use Fire Elementals all that much though. Fireballs are almost always going to be handy though, and I'll probably have a few mages with that ability.
Air. Air is a mixed bag. It has an awful first level spell. It then has an incredibly good second level spell. Maelstrom does up to 40% damage to all units within two tiles of the caster. Its a really really useful ability, and a typical mage attack force will lead with a few maelstroms to weaken the foe, before attacking them with summons. Air3 gives Air Elementals, which aren't all that powerful, but are fast, ignore terrain and are good at cleaning up weakened foes since they create weak Lightning Elementals. I'm going to be getting quite a lot of Maelstrom mages.
Earth. Earth is one of the better manas. It has a secondary ability which is to drastically increase the chances of discovering new resources in mines. If you stockpile 10 earth mana then it is not unusual to be discovering multiple new resources every turn. The spells are all good too. The first level creates a stone wall in the city, which is helpful for defence in a pinch. The second level gives Stoneskin to the mages, which turns them from assassin fodder into actually legitimately tough units. The last spell is earth elemental, which is a slow lumbering unit which has a very high base strength. A very nice stack defender.
The tower of the elements gives all elementals the strong promotion. It also creates an elemental guardian for the city, which I have never ever needed. Earth Elementals, Fire Elementals and Air Elementals as well as the Aurealis summons from Sun all don't care too much about being strong. The two elementals that really feel the benefit are Water and Ice. Ice Elementals because they can't get much mana affinity, and have a much lower base strength. Water Elementals because their special ability is to split, and strong water elementals can split then split again, making them a hell of a lot better.
Anyway, the boost to Ice Elementals and the fact that Ice Elementals are a core part of my force means that I'll be getting this technology and tower early. Early access to Maelstrom is also a key feature.
[SIZE="3"]
Divination[/SIZE]
Because knowing is half the battle
Divination has 5 different nodes associated with it, although only 4 are needed to build the tower. The tower of Divination is awesome, as I've already said. Of the mana that can be used with divination, 2 are almost always useful, 2 are almost always awful but have good secondary effects and 1 is situational. It also unlocks the Shrine of Sirona, a vaguely useful wonder that gives out some free healing.
Sun. Sun has no secondary node effect. It has what is for my money the best spell in the game, as well as two decent spells. I'm actually annoyed at the Sun 1 spell "Scorch", because it gives people a method to destroy some of my lovely snow

. It also turns plains to desert. Whoo. The 3rd level spell summons an aurealis, which has mana affinity 2, making it very powerful if you stockpile sun mana. Aurealis have no fun secondary abilities though, so I've never been a big fan. The main draw of Sun however is Blinding Light. Blinding Light immobilizes any enemy units within one tile of the caster for two turns. There is a chance to resist, but it can blunt an assault incredibly effectively. Even non living units can be affected. This spell gives you so much time.. letting you pull up defenders, or rip apart an enemy squad. It's a nasty nasty spell, and will be key to my defensive strategy.
Mind. Mind is the other really good mana in Divination. Brilliant spells at every level. Brilliant secondary effect. Every mind node gives a 3% bonus to research rate. If you aren't using your nodes, you could do a lot worse than set them all to mind nodes to get that research edge. And speaking of research edge, Mind 1 gives the spell Inspiration, which adds 3 research points and a Great Sage Point to a city. That is better than an elder council. At level 2 is Charm Person, which is kind of like a slightly worse Blinding Light. It stops them attacking, but lets them move and is partially countered by Law 1 and doesn't affect non living units. Mind 3 is domination, which lets you steal the best enemy units. Very very awesome, although it has a resist chance, and if the target resists then you lose the ability to cast the spell. Also partially countered by law 1. Mind is one of the best mana in the game. It's not going to carry the day on its own, like death, but almost every empire has a good use for mind mages.
Law. Law spells suck. It does however have a really good secondary effect, dropping maintenance by 5% per node. If you stockpile this then you can effectively run your empire for free. Law 1 acts as a counter to mind spells, and the command promotions. Law 2 is a crappy summon. Law 3 is a decent unit buff that really belongs at level 2. I think Law would be a lot better balanced if they put order high priest spell which allows an infinite Happy Cap as the law 3 spell, removed Host of the Einherjar from the game and put valor as the level 2. Law is not going to be used by me, even though I have the node in my capital.
Spirit. Spirit also sucks, but slightly less. Probably worth getting 1 guy with spirit 1 or 2 to give the promo. Spirit 1 gives Courage which is a slight buff to heal rate, and allows units to ignore fear effects, handy on rare occasions mainly involving dragons. Spirit has a handy secondary ability to increase great person generation, but I find Mind, Law or Enchantment are generally more useful when focussing on economy.
Life. Life is either awful or brilliant at every level. Extremely situational. Sanctify is great if you want to cleanse hell terrain, but bad if there is no hell terrain on the map. Destroy undead is fantastic against an undead heavy enemy force, as one of the few lethal spells it can kill entire stacks of undead easily, but bad in any other situation. (Although remember, summons like spectres will generally be created on the opponents turn so will attack before you can destroy them. It completely wrecks their utility as stack defenders though, and if you can kill the mages then the spectres are gone.) Resurrection is really nice if you have a good civilization who died unluckily, but bad if you have a crappy civ hero (I can take an archmage out of commission for 7 turns to bring back Wilboman with no XP? Pass). Not going to be using life at all this game unless I need to.
The free technology from the tower of divination is great. It means I can get to sorcery fast. Divination also includes the fabulous Sun and Mind mana, which is another reason to prioritize it really highly.
[SIZE="3"]
Sorcery[/SIZE]
The last type of mana is unlocked at sorcery. Sorcery is an extremely important technology because it unlocks Mages, the level 2 spellcaster. But it also unlocks Alchemy Labs, a nice but expensive science boosting building. And metamagic mana.
Metamagic. Metamagic is a handy node. You're going to want a few mages to know some spells. It has a secondary ability of making your spells more powerful, mildly more damaging or harder to resist. The first level spell gives you a floating eye minion. Handy for recon. Second level is your bread and butter in a tower of mastery strategy. Dispel magic is the spell that makes this victory condition a possibility, since it lets you shuffle around your nodes to your hearts content. It also removes spells that affect your own or enemy units. Summon Djinn is the capstone ability. A summon that has affinity to all mana, it can often end up being the strongest summon if your nodes aren't set up to specialize in Earth, Air, Fire, Water or Sun but it is a bit generic. Metamagic is an essential mana, at least on a few mages.
Going forward I will be setting up around 4 or 5 mages to act as Nodemasters, with dispel magic promotions to dispel and rebuild nodes as needed. Properly controlling your nodes is a very important part of the magic based gameplan.