Dread Necromancer Class Features
Weapon and Armor Proficiencies:You get light armor w/ no ASF, meaning you'll want mithril breastplate ASAP, w/o costing you too much. You get all simple weapons, and a single martial proficiency. The most common choice is the Longbow, but any reach weapon can be great too. Lance works for mounted builds, and is great w/o any investment into the mounted feats, and the Guisarm can make trip attacks, too, and being reach you don't have to worry about being tripped back, just about being disarmed. Don't pick the mighty 2H Sword: you shouldn't rely on your weapons as the way to do damage, but rather your spells and class abilities to disable opponents (the lance is an exception to that, being capable of really getting a lot of multipliers on a charge really easily).
I also like the Throwing Axe: you threaten, you have ranged options, and its finessable. One of the last weapons I used was a +1 Spellstoring Throwing Axe (which generally was under a Brilliant Energy Aura from a Wizard), and I must say it was pretty awesome: Spellstoring only cares about the spell level, not the spell slot, so you can put in funky metamagic combinations. I don't know if its RAW, but a Chained Ray of Exhaustion fits in just as well as a spell that takes a 3rd level slot, and I believe will hit every one as a normal Chained spell (Spellstoring doesn't change its range, nor does "Chain" change it away from a "targeted spell", after all).
Charnel Touch:Useful at the lowest levels for damage, but will be used for healing yourself and your undead between battles after that.
Rebuke Undead:Turning isn't that bad of a strategy at low levels, but starts to suck exponentially with level. K's handbook has the best advice on it. It's really stupid, but you just gain Rebuke Undead "as a Cleric, see p 33 of PHB", which in turn refers to p 159 of the PHB. Its all worded to work off your Cleric level, of which you have none. RAW, a Dread Necro has no ability to Rebuke anything. Had they just said "as a cleric of their class level", it would work. No sane DM would play it that way, but at this point the hope for errata is long past, so you have to appeal to some common sense.
Lich Body:the best thing a Melee DN has going for it. DR 2 at 2nd is pretty awesome, but as usual, the DR doesn't scale well.
Negative Energy Burst:As mentioned by K in his handbook, its primarily a quick heal ability. If you aren't undead or tomb tainted (possibly as a result of DM nerfage), this ability becomes basically worthless, as you would be hurting yourself to use it.
Fear Aura:This ability is soooo freaking good. You'll have a ton of fear effects that leave them shaken, that combined w/ this you can frighten everyone. Combine this w/ Intimidate's demoralize opponent and you become a one person per round frighten machine. Stack it with the 'Never Surrounded' skill trick from complete adventurer and you can frighten every enemy adjacent to you.
Advanced Learning:Its good, but can be hard to find a lot of spells that aren't essentially duplicates of what your spell list already provides. Recommendations for individual spells can be found in the Spells section of this guide.
Mental Bastion:You'll either become a Necropolitan early on or a Lich much later, but the bonus on saves is good until then.
Scaberous Touch:By the time you get this, you don't want to be using it, unless you still are focusing on Charnel Touch, which is losing power by this point. As such, this is more for flavor. You could buff w/ Spectral Hand, activate this ability, cast a touch spell, and deliver a Charnel Touch all w/ one attack, but that's a lot of effort for what you get.
Undead Mastery:This ability is AWESOME! Hordes and Hordes of skeletons on your side. Unfortunately, its keyed off your class level, so if you PrC out after 8th, you'll not get full benefit out of it, but it probably is worth it (even having 4 times your HD in undead is usually more than enough as a PC): You'll have (8 X Cha) + (4 X HD), which should be enough. Of course, even the normal undead HD limit from Animate Dead is enough to strain most campaigns to the breaking point, so the primary benefit will likely be the enhanced stats and HP on your undead. Note that only the HP bonus will stack with the 'Corpsecrafter' feat, however.
Light Fortification:See Mental Bastion above. If a rogue actually had Grave Strike, and you were a Necro, this would still apply RAW. That's a highly situational benefit, though.
Evervating Touch:This is a powerful ability, particularly when combined with a wicked touch spell (like Harm, for example). This is one of the few real benefits of leveling past 8 as a Dread Necromancer.
Craft Wonderous Item:Considering your limited spell list, you probably don't want to take a lot of item creation feats. Getting one for free isn't bad, although it comes pretty late in the game.
Lich Transformation:According to Wizards Custserv (Incident: 070501-000021), you do not gain the Lich template with this ability. You do gain the undead template and have lich-like class abilities. Clarification is needed concerning the phylactery. RAW gives a useless phylactery but the class description implies that you would gain the phylactery ability. If you are already undead, there may be no reason to take this level as you only are gaining the 9th level spell and the ability to make a useless wonderous item for free. If you're DM rules that the phylactery is functional, then an undead Dread Necromancer will have to pay for a True Resurrection before taking this level.
Familiar choice is really important, as they're much more powerful than your standard choices
At 7th, the DN gets the equivalent of Improved Familiar for free, but RAW it doesn’t have to match your alignment at all. You may want to wait a few levels to get the Stiched-flesh Familiar feat (see feat section). There’s 2 choices which really stand out: Quasit and Ghostly Visage. Realize that since these are familiars, there special ability saves will increase at 10+1/2 your level + stat, which is slow, but just a little less rapidly than your spells and class abilities, generally. (Note: the Monster Manual listing for Imp and Quasit has been errata'd from the SRD version; the MM versions allow up to any two polymorph forms, and is very, very powerful: if your game uses only the books, then I suggest you take one of these two familiars.)
- Ghostly Visage: (K pointed out this one): Gives some great immunities, if you haven’t gone Necro yet, and if you want to melee it has some nice uses. Paralyzing gaze affects everyone w/in 30' every round, which is awesome.
- Quasit: These guys have detect magic at will, invisibility, and can polymorph into a Wolf, improving both your sneakiness and your stealth. A great way to really confuse your allies is to max out Disguise and have your familiar always in Wolf form. They’ll never figure out what you’re playing! They should ALWAYS have Detect Magic and Invisibility up and running. Between you having Detect Undead up when its appropriate and the familiar doing its thing, you should have a pretty good thing going. The poison DC scales somewhat, but is a weak effect.
- Imp: A close second, IMO, to the Quasit. They have a Boar form instead of a Wolf. Although it has a better Con, it lacks the movement, and RAW, you won’t get any extra HP from the higher Con. They get both poison and Suggestion that scales ok: this might make it better than the Quasit if you plan on doing a lot of subterfuge.
- Vargouille: The Paralyzing Kiss can be used to take out a massive population pretty quickly, but you won’t be getting control over them. The fact that your familiar can’t even talk to them really prevents anything useful happening from it. The Shriek effect is of too low of a DC to be really useful, and doesn't scale well (having Con based abilities and undead really sucks).