AKA
Atrele's Wizarding Guide, aka Hogwarts with less Rowling Mold-Huffing
Alright! So if you're reading this, you're either bored or you have no idea what you're going to do as a Wizard. Well, this bo^H^Hforum thread will help work out just how you want to bring your magical wrath upon anything looking at you funny.
Tier 1 and Tier 2 Skill choices.
By and large I won't go into the lower tier skill choices. What skills best support your Wizarding will be described with each particular "path". However there are a few standalone skills that merit note.
Mortal
Athleticism: Wizards do not natively get a way to have 1/2 AP movement cost, and do not natively have flight, so Athleticism remains useful, even with Blink.
Strength and Stamina: Both quite useful, for carrying more spellgems and/or weapons and/or whatever. Wizards do not get any sort of HP improvement skills, so Stamina both allows you to take another hit, or take another hit of SM.
Tap Font and Tap Ley Line: Situationally useful, but when available really, REALLY useful. Good for buffing and charging spellgems, just watch the MP: people get cranky if you drain the font and then the next time you go to use it it'll blow up in your face like nine times as well as be barred so hard you're better off not using it. It's happened. As a note, dropping the right potion on a font can increase it's reserve by a whopping 20 points which can do a lot to mollify said cranky people. Tap Ley Line allows you to access fonts remotely as long as you're on it's ley line. That can be useful, but it's fairly limited in location: any movement off of the Ley Line cuts the connection immediately.
Sorcerer
Alchemy and Deep Alchemy: The Wizard's biggest source of self-buffs, investing in Alchemy will give you means to improve your damage, improve your accuracy, improve your defense, recover HP and MP, a source of flight, and chances to invisibly teabag people. Deep Alchemy makes Alchemy far easier to manage and gives you a few more potion options.
Heal Self and Mystic Vigor: Heal Self is a handy on-demand poison removal, other than that there's more effective healing options. Mystic Vigor is situational, but if you have a lack of AP and an abundance of MP, it's an option. You just have to find a way to keep your MP stocked.
Pattern Weaver:Share your spells with your friends, and share your spells with your enemies for cheaper! Not a necessity, but if one intends to keep a large number or variety of spellgems in stock for whatever reason...
Sorcerer's Might: The Wizard MP recovery system of choice. Try to do this in a safe place, not only are you injuring yourself, but a full SM sesh will render yourself unable to heal for up to an hour or more.
Tier 3 Support Skills.
Before going into the various means the Wizard will wreak havoc upon their foes, I'd like to go into some of the skills that are useful to ANY Wizard.
Blink: The Wizard Travel skill. Allows you to move to any tile within view, skipping over tile between. Add a flying potion, and a Wizard can cover an amazing amount of ground. Athleticism will reduce the cost of Blinking into rough terrain and water.
Cosmic Mastery: More MP is never a bad thing and this along with Cosmic Affinity and Magical Reserves will give a Wizard a ridiculous amount of MP to play with.
Cosmic Oneness: You regenerate MP twice as fast. Useful I suppose, but I don't see it.
Greater Infusion: Requires Infuse from Sorcerer. Allows you to infuse for less MP. Infusion is kind of the weird thing in the Nexus, so it can be useful if you're pushing for your side to "win" the current game but it's mostly just "something to do"..
Glyph Mastery: Makes your glyphs and dispels stronger. Useful if you use glyphs, but they're very expensive support spells.
Spell Parry and Spell Turning: A pretty potent defense against other spell users, and also funny when their spell rebounds in their face. Rewards having a thick spell book: the right spell choices can make you into a particularly situational headache.
Attuned Palate and Persistent Spellcraft: Useful for lategame buffing, this can allow you to pre-buff for cheaper.
Augury: A fun curiosity to dink with if you want to keep up with the local news.
Spell Choices.
As for spells, like any good Wizard should know a few. Spell choice is fairly cosmetic: There's really no difference between Caustic Bolt, Force Bolt, or any "Bolt" spell (or any two touch spells, or any two similar spells) aside from the type of damage, which is only relevant if the target has soak or resistance to the damage type. When choosing which spells you want, you'll want to consider the likely defenses of potential targets: Fire and Acid usually aren't particularly good against demons, for example. The minimum you will want to learn, in all cases, is at least one support spell for your preferred combat tree, and all six spells of your preferred damage type to maximize damage and access to that element's capstone ability. A full spell set of any particular element will cost 30 T2 CP and 50 T3 CP, so a Wizard should not have any trouble fitting at least one into their build, and two aren't out of place either. For a quick rundown of capstone abilities:
Acid: Deals +4 damage to 0 or less Acid Soak
Cold: Reduces soak by 1 across the board up three times
Death: Causes a target to die at 15% HP or less
Electric:Reduces defense by 5% up to three times
Fire: Double damage against doors/forts
Impact: +2 damage
Piercing: Effective soak is reduced up to 2 points
Slashing: Chance of critical hit for +5 damage
Arcane: Reduce target MP and deal bonus damage (Only available with Deep Spellcraft)
The Trees
The Wizard has roughly four options when it comes to the particular means of damage dealing: Ranged Spells, Touch Spells, Treeless, and Guns.
Spells
In general, spells will use the same supporting skills. Pattern Weaver or a high MP pool is required to use offensive spells frequently, Fortify Spell to improve damage, Arcane Affinity to improve MP economy and Eldritch Mixing to take advantage of multiple capstone abilities. (Cold + Acid Eldritch Mixing tends to be a popular combination, for example) Note that to take full advantage of Eldritch Mixing, you only need to have ONE full spell set, but you will have to use that type to receive your full spell affinity bonus and both capstone abilities. (For example, if you only have the Cold spell set, you need to cast a cold spell or use the cold Eldritch Mixing charged attack.)
In all cases of the Wizard relying on spells, their MP will be their most important asset: Cosmic Affinity and Cosmic Mastery add 30 MP, pushing the Wizard's max MP to an impressive 94. Arcane Affinity's biggest boon to spellcasting is making buffing and T3 autohit spells cheaper (As with charging those specific spellgems).
Ranged
Ranged spells come in two types: Autohit, and Ranged. Autohit spells are relatively high cost for their damage and automatically hit, while Ranged spells do more damage for cheaper, but require the Spell Combat tree. The full Spell Combat Tree (Spellcraft + Spell Combat and Battle Magic) gives a total of 70% accuracy, which can be easily improved by a Sharp Vision spell and a Combat Clarity potion. Fully kitted, a T3 ranged spell will hit for 22 damage for 3 MP without modifiers, while T3 autohits inflict 17 damage for 4 MP. Ranged spellcasters can also take advantage of the Spellwand skill, which grants an innate weapon attack that can be charged with spellgems, but this just gives the spellwand the damage type and damage value of the spell for up to 15 shots. Spellwand attacks are not spell attacks, which can be important.
Touch
There's really only one touch spell for each element, which fully kitted inflicts 17 damage for 2 MP. Touch spells have an important synergy with their matching elemental auras: having the aura up will increase the spells damage by 6, to 23/2 MP. Note that A) only one aura can be on at a time which makes damage switching tougher, B) Touch spells run afoul of enemy auras, and C) Touch spells don't get Capstone bonuses. Touch spells are touch attacks, which means that it either uses the higher of 70%, Hand to Hand, or Melee accuracy. While the Hand to Hand and Melee trees on their own will not grant accuracy over 70%, having those trees means you can use buffs like Combat Clarity and Tiger Claw to make these spells even more reliable (as well as grant an offhand option if your spells just aren't working!). Note that Tiger Claw is useful for touch spells, but Conjure Sinews is not. As a note, even a touch spell user will find autohit spells (particularly T3) valuable for when accuracy or that capstone bonus matters.
Treeless
Treeless is the least demanding on the Wizard's low-tier CP, and take advantage of two things. The first is that Autohit spells (any "Dart" or "Bolt" spell) well... automatically hit without consideration for accuracy. The second is that Touch spells have a minimum of 70% accuracy, which is higher than even a full Hand to Hand tree (which tops out at 65%). Because of this, it's entirely possible to dismiss the combat trees entirely and just rely on those two types of spells. However, Autohit spells (especially Tier 3 autohits!) are expensive for the damage they deal, and 70% accuracy really is kind of low at T3, and that accuracy cannot be improved by ANY means without investing in a combat tree. However, this does mean you can ignore accuracy to an extent, and that's at least 60 CP you can put to more interesting uses. If you're going treeless, it becomes more important to establish a large MP pool with Cosmic Affinity and Mastery. Arcane Affinity can ease the strain on your MP, and Fortify Spell is necessary to get as much damage as you can out of those spells.
Guns
Wizards get three skills involving guns, all of which makes them gunslingers of impressive power. Arcane Marksman allows the Wizard to spend MP instead of ammo firing guns using any damage type the Wizard knows at least one spell, and also use any aura spell they have on for supplemental damage. Arcane Deadeye improves Arcane Marksman damage by the type's spell affinity and allows access to the type's Capstone, all for 1 MP. Add in a common rifle and a Sharp Vision spell, and the Wizard is pretty much set for combat. Gunsmithing is highly advised if one is going Gunwizard, but is not necessary, even if one doesn't have a source of repairs: Conjure Gun makes sure the Wizard will always have one at hand. But it's still, you know, a shotgun. That can be a problem if accuracy becomes really important. Unlike with spells, establishing a large MP pool is not as necessary: Arcane Marksman attacks are very cheap and unless the Wizard is throwing around MP left and right they'll probably be fine in that regard. But even then... you have a gun, dude. Note that you're going to need at least one unit of ammo in a gun to fire it, regardless. If a Wizard decides to rely on conjured guns, Cosmic Affinity at the minimum won't be out of place: 6 MP every 4-6 shots adds up real fast, especially if you're not keeping track of your MP and are prone to forgetting to use Arcane Marksman.