I often see posts from people asking how to optimise a wizard, or wondering if Wizards are even viable in 4th.
The most common response I see is to start as a witch (for instinctive diction) and then move into wizards apprentice and go from there. This is a hold over from when 4th was first released and channeling was arguably not worth the effort, and I don't believe it is necessary any more for reasons I will explain below.
Wizards apprentice and petty magic
Whichever wind you channel, you are going to start your career as a wizard apprentice/Acolyte/ or whatever else your order calls students of magic.
The only magic open to you at this point is petty magic, and frankly it might be best to skip it.
From a legal perspective, petty magic is considered to be dark magic and therefore discouraged at best. This is not something you are going to be taught by your order, and not something you should practice openly.
From a rules perspective it is not great - at least not in combat. Dart is probably less effective than a good staff or crossbow, so unless you desperately want to fling spells at people you should probably give it a miss. You are not a wizard yet, you are essentially a fighter. Get used to it.
This is probably the single most common complaint I see about people playing Wizards apprentices. They want to cast spells but end up hitting people with a big stick instead. WFRP characters start small. Relax, get used to using your weapon, that way you will always remember it is there as a back up.
If you are going to flaunt the law and make use of petty magic, stick with utility spells. Look for things that give your party capabilities they wouldn't have without that spell. Open lock can fill in a gap in the party of you don't have anyone capable of picking locks for instance. Eavesdrop is another spell that can trivialise some situations.
On the whole though, you essentially a not so big or stupid are a fighter with a big stick. And not a very good one at that, because you are going to be spending your experience on things that you can't even make use of yet.
Aethyric Attunement
The big dilemma facing a Wizards apprentice is that aethyric Attunement is hugely useful later in your career but completely useless now, yet has to be bought now because it doesn't show up in later talent lists.
You need to take it, but it is a point sink that will do nothing immediately other than put you behind your allies in terms of effective advancement. That means it should probably be the last thing you take before graduating to become a proper wizard.
You need to get it once. This will mitigate miscasts when channeling, and make your channeling more effective. If you can spare the experience I would advise taking it a second time for an extra boost to channeling. You don't need any more than that because "winds of magic" gave you more efficient ways to boost your channeling that I will talk about later.
Characteristics
It goes without saying that you should be pumping Int and WP as high as you can. As a wizard, they will be your most useful characteristics by far. All through your career you are going to be judging whether it is more cost effective to boost Int/WP or language(magic)/channeling, or wether there is a different way to boost those skills more cheaply.
I would probably start with WS however as an apprentice, because it is going to be more immediately useful while you rely on your staff to get the job done.
Skills
Basically the same advice as above, but it bears repeating; itgoes without saying that you should be pumping language(magic) and channeling as high as you can. As a wizard, they will be your most useful characteristics by far. All through your career you are going to be judging whether it is more cost effective to boost Int/WP or language(magic)/channeling, or wether there is a different way to boost channeling and casting more cheaply.
After that melee (pole arm) is going to be useful, especially early in your career. In fact I would focus on this first as an apprentice, for the same reason I would focus on ws first. Channeling and language(magic) are mostly useless until you actually have some spells to cast.
Cool is another useful skill to have, because not only will it help you resist fear but it will help retain the magic you have channeled when you get interrupted. And you will get interrupted.
Fancy robes
A small change with a massive effect is that magical robes now give bonuses to channeling - and you are given them for free when you rise in your career!
This means that as a graduate wizard with some standard robes you will be getting +1SL on your channeling tests (in addition to the aethyric Attunement bonuses you picked up). This should be enough to channel the power to cast a CN 4 or maybe even 5 spell in a single round.
As you get more powerful, and want to cast more powerful spells, your robes get fancier and the bonus grows with you.
This is why you only need 1 or 2 levels in aethyric Attunement.
Rituals are your friends
The second thing winds of magic added are rituals, and they provide a huge boon to Wizards.
Enchanting your staff will provide +1SL on casting tests and you should be capable of performing it during your second career as a newly graduated wizard. If you have access to your college (or an outpost of it) then you should probably be able to get access to a grimoire containing this ritual. It strikes me as something that should be fairly ubiquitous. Performing it from a grimoire requires channeling a lot of power however and as a graduate will require a lot of dice rolling (I was tempted to do it as part of my Wizards graduation until I realised that it would take an average of 200 or so channeling tests) and quite a few rolls on the miscasts table. Learning it will make it much more manageable and is a bargain considering it is 100exp for what is effectively an extra level of instinctive diction that doesn't increase the experience costs.
The second ritual you are interested in is summon familiar. A power familiar assisting you will grant +20 to both your channeling and casting tests. This takes a lot more channeling, so is probably best left until a bit later in your career. It is also probably harder to convince your college to give you access to it. Given the high CN it is also probably worth learning, if only to avoid endless dice rolling, but 450rxp for effectively getting +20 to two skills (and it helps with research as well) will quickly become a bargain as the costs of getting more advances in those skills mount. Once you have gotten your first familiar it can even help you summon your second.
Potions
They are expensive to buy ingredients for, but making them relies on a skill you are boosting anyway so potions should always be something you consider for your arsenal.
There are several potions that benefit you, but the most important is probably a draught of power because it can half the CN of a ritual - making it easier to get the enchanted staff and familiar mentioned above.
Spells
As I have mentioned, it is going to be some time before you have any effective combat spells available to you so you need to get comfortable using your staff until well into your second career.
Once you do however, you want to learn spells that you can reliably cast after channeling for a single round. Remember that you don't have to choose your spell until you know how much power you have channeled however so it is ok to learn one or two that need a higher channeling roll to prepare, just so long as you have something a bit more reliable as a backup. This means you are aiming to cast a spell every other round.
As a freshly graduated second career wizard with 2 levels of aethyric Attunement and standard robes you will gain +3 to your channeling tests. Given that a successful test should get you at least 1SL, you should be able to reliably cast spells of CN 4 , maybe CN5.
As you climb the ranks and gain fancier robes with higher bonuses, not to mention better skills and maybe a power familiar, the power of the spells you can reliably prepare and cast will grow. By the time you are a wizard lords with elaborate robes you will be gaining +5 on channeling tests with a further +20 to your test from your familiar (or +40 of you have two of them) allowing you to reliably cast the most powerful spells.
So why not start as a witch
In the early days of 4e, channeling was not seen as worthwhile by many. Now that reducing CN to 0 by channeling IS a viable game plan, I think instinctive diction is less essential than it once was.
Of course instinctive diction is still really good, but you have to balance the cost of taking a whole career to get it, further extending the amount of time you will be relying on your staff with no benefits until you finally get around to learning spells.
Given that you can probably get an enchanted staff early in your career that will grant an extra SL anyway, and you will be channeling to reduce CN to 0 and overcasting through that, instinctive diction can probably wait until your third career. The only real problem is that you will not be immune to miscasts when rolling total power.
It is a balance. If you are willing to wait to become effective and actually start casting magic, then starting as a witch to gain instinctive diction might be worthwhile (and has the benefit of role-playing a societal misfit as they find their way into the college's of magic), but I don't think it optimal.
