I have seen way to many god awful death knight guides, so i am going to make one for PvE DPS and Tanking, as well as PvP.
First off the most important thing to remember when playing a death knight is to have a good rotation(Sequence of spell/skills in order to maximize DPS/TPS).
Acronyms
PS: Plague Strike
IT: Icy Touch
OBL: Obliterate
FS: Frost Strike
DS: Death Strike
DC: Death Coil
BS: Blood Strike
HS: Heart Strike
PST: Pestilence
DnD: Death and Decay
SS: Scourge Strike
UB: Unholy Blight
HB: Howling Blast
BB: Blood Boil
RP: Runic Power
I will start with PvE dps.
Blood is physical damage based, is also the probably the most RNG(random number generating) dependent, due too Sudden Doom.
Cookie Cutter Blood Build
Rotation:
Single target: PS>IT>DS>HSx4> RP dump
AoE: DnD>PS>IT>PST>DS>BB>BB> RP dump
Blood Build with Pet
Very strong Single Target damage, kinda lacking on AoE ability, this is a very underrated build.
Rotation:
Single target: PS>IT>DS>HSx4> RP dump
AoE: DnD>PS>IT>PST>UB>DS>BB>BB> RP dump
Next up is frost, frost is my personal favorite spec, frost has both Physical and magic type damage, mainly Frost Strike and Obliterate. Also Frost strike takes Priority over all else, so when ever you have a slight space in Rune Cool Downs use a Frost Strike.
Cookie Cutter Frost Build
Rotation:
Single Target: PS>IT>BS>BS>OBL>OBL> RP dump
AoE: PS>IT>PST>HB>OBL> RP dump
Frost with UnHoly Sub spec
This is a more gear dependent build
Rotation:
Single Target: PS>IT>BS>BS>OBL>OBL> RP dump
AoE: PS>IT>PST>HB>OBL> RP dump
And NO! as of right now there is no good Duel wield spec for frost, or any spec for that matter.
DUEL WIELDING IS BAD!!!!one!
Now on too UnHoly. UnHoly is based around diseases damage, the only physical done with UH is Blood strike, Uh has alot of diffrent builds that can be played, and they all very with gear.
I really can not say there is a cookie cutter UH spec, So i'm just going to post some of the more popular builds.
UnHoly /w a blood sub spec
Rotation:
Single target: PS>IT>BS>BS>SS>SS> RP dump
AoE: DnD>PS>IT>PST>UB>BS>SS> RP dump
00/10/61
This is a geared UH DPS build
Rotation:
Single target: PS>IT>BS>BS>SS>SS> RP dump
AoE: DnD>PS>IT>PST>UB>BS>SS> RP dump
07/10/54
This is a similar spec to 00/10/61, but requires less gear
Rotation:
Single target: PS>IT>BS>BS>SS>SS> RP dump
AoE: DnD>PS>IT>PST>UB>BS>SS> RP dump
Tanking
I'll start by explaining a Few important tanking terms and concepts.
Parry haste: After every parry be it done by a player or NPC the nextattack done after the parry is 40% faster. This is why DW tanking is bad, because it increases you chance to be parried, unless your hard capped on expertise(49).
Diminishing Returns on Avoidance
│------│expected││diminished││expected││diminished││expected││diminished│
│rating│-│dodge│---│dodge│----│parry│----│parry│----│miss│-----│miss│
│0│------│0.00│----│0.00│------│0.00│-----│0.00│----│0.00│-----│0.00│
│100│----│2.54│----│2.58│------│2.03│-----│2.03│----│0.81│-----│0.81│
│200│----│5.08│----│5.01│------│4.07│-----│3.90│----│1.63│-----│1.54│
│300│----│7.62│----│7.31│------│6.10│-----│5.62│----│2.44│-----│2.20│
│400│---│10.17│----│9.49│------│8.13│-----│7.20│----│3.25│-----│2.81│
│500│---│12.71│---│11.55│-----│10.17│-----│8.67│----│4.07│-----│3.36│
│600│---│15.25│---│13.51│-----│12.20│----│10.04│----│4.88│-----│3.87│
│689│---│17.51│---│15.16│-----│14.01│----│11.17│----│5.60│-----│4.29│
│700│---│17.79│---│15.36│-----│14.23│----│11.31│----│5.69│-----│4.34│
│800│---│20.33│---│17.13│-----│16.27│----│12.49│----│6.51│-----│4.77│
│900│---│22.87│---│18.82│-----│18.30│----│13.60│----│7.32│-----│5.18│
│1000│--│25.41│---│20.42│-----│20.33│----│14.64│----│8.13│-----│5.55│
│1100│--│27.96│---│21.96│-----│22.36│----│15.62│----│8.95│-----│5.90│
│1200│--│30.50│---│23.42│-----│24.41│----│16.54│----│9.76│-----│6.23│
│1300│--│33.04│---│24.82│-----│26.43│----│17.41│----│10.57│---│6.54│
│1400│--│35.58│---│26.17│-----│28.46│----│18.23│----│11.39│---│6.83│
│1500│--│38.12│---│27.45│-----│30.50│----│19.00│----│12.20│---│7.10│
│1600│--│40.66│---│28.69│-----│32.53│----│19.74│----│13.01│---│7.35│
│1700│--│43.20│---│29.87│-----│34.56│----│20.44│----│13.83│---│7.60│
│1800│--│45.75│---│31.01│-----│36.60│----│21.10│----│14.64│---│7.82│
│1900│--│48.29│---│32.11│-----│38.63│----│21.73│----│15.45│---│8.04│
│2000│--│50.83│---│33.16│-----│40.66│----│22.33│----│16.27│---│8.25│
│10000││254.14│---│66.19│-----│203.31│---│38.50│----│81.33│--│13.47│
Dodge, parry, and miss are subject to diminishing returns. When you determine how much dodge/parry/miss you gain from rating or defense, it must be converted into the diminished amount. The diminished amount is what is added to your dodge/parry/miss chance.Diminishing returns on avoidance do not work like diminishing returns on stuns! There's a common belief that if you avoid an attack, your chance to avoid subsequent attacks is reduced, which is not true.Basically, you get less avoidance for every point of rating than you got for the last one.
-The diminishing returns on dodge, parry, and chance to be missed are independent of each other
-Avoidance contributed by defense is subject to diminishing returns
-Your base avoidance and avoidance given by talents and racials is NOT subject to diminishing returns
-Block chance is not subject to diminishing returns at all (Not really that important for DK's)
-The miss chance on the defense tooltip does not have diminishing returns
Effective Health
Is kinda complicated, and i will probably do a bad job explaining it, so I'm just give you a link the TankSpot Forums.
Effective Health
(sue me I'm lazy)
Now a Few specs
Frost Tanks have the most avoidance, but the lowest Health.
Cookie Cutter Frost Tank
Rotation:
Single Target: PS>IT>BS>BS>OBL>OBL> RP dump
AoE: PS>IT>PST>HB>OBL> RP dump
This spec is more for Trash tanking, because your Giving up 9% Crit on your main Ability (OBL).
AoE Frost Tank
Rotation:
Single Target: PS>IT>BS>BS>OBL>OBL> RP dump
AoE: DnD>PS>IT>PST>HB>OBL> RP dump
UnHoly is a really week tank spec as of right now, but is still very viable for AoE fights.
Deep UnHoly Build
Rotation:
Single Target: PS>IT>BS>BS>SS>SS> RP dump
AoE: DnD>PS>IT>PST>BB>UB>SS>RP dump
High Health UnHoly Spec
Rotation:
Single Target: PS>IT>BS>BS>SS>SS> RP dump
AoE: DnD>PS>IT>PST>BB>UB>SS>RP dump
Blood Tanks are doing Very well in 3.1, It is a Flexible tree that's good for most boss Fights.
Deep Blood
I Personally do not like this build because as a tank your HP is over 75% maybe 45% of a fight, but non the less it a good build
Rotation:
Single target: PS>IT>DS>HSx4> RP dump
AoE: DnD>PS>IT>PST>BB>BB> Rp dump
Blood Tanking, Mixed spec
This is a more played blood spec but has low TPS(low compared to other Builds, still more then other Tanks by a good amount).
Rotation:
Single target: PS>IT>DS>HSx4> RP dump
AoE: DnD>PS>IT>PST>BB>BB> Rp dump
Blood /mid UH build
This spec Uses UB for more AoE threat, but is also good for Boss fight that need a high Health tank.
Rotation:
Single target: PS>IT>DS>HSx4> RP dump
AoE: DnD>PS>IT>PST>UB>BB>BB> Rp dump
Now Remember, a good tank is a tank that can bend to a situation, and every spec is subject able to veneration based on gear or a specific stat.
EX: If you have High Expertise you can get Blood-Caked Blade over Ravenous Dead, BBC is more TPS but also gives you another chance to be parried, hence why you need high expertise.
Well as of right now my wrist are inflamed and i have full blown carpal tunnel, but i'm going to move on a PvP.
PvP
A Death Knight dose not need as much resil as other classes, because Death knight are a extremely survivable class, and have a ton of out's such as IBF(Ice bound fortitude), UA(unbreakable armor) and DS(there are alot more). I personally hover around 650-750 depending on the class i'm fighting. PvP on a Death knight is not hard by any means.
Here are some Popular pvp builds, but like any other spec it is based on your play style and team make up.
Frost/blood
This is more a 2's / BG build made for burst and survivability.
Frost/blood
This build has very little survivability but has more Dmg out put, more for 3' with a healer.
Also just a Note but While under the effects of Lichborne you can use CD to heal yourself. the Macro I use for it is
#showtooltip Lichborne
/cast !Lichborne
/cast [target=(your name here)] Death coil
Unholy Frost
This spec has a lot of snares and lows, and is a very strong pvp build.
Blood as of right now is a extremely week spec for pvp, but is some what viable in 5's and 2's.
Blood/frost
This is the most played blood build, and it's fairly good, has a lot of snares, also a nice thing to know is that blood worms are always aggressive and some times pop rouges out of a vanish.
Blood/UnHoly
This build is a spec for survival, over damage, and being able to lock down healers with a extra stun from your Ghoul.
There is much. much more I could say about every topic here, but I am doing my best to put every Death knight thread ever made into one. any questions anyone may have I will be happy to help. If you have any think constructive to say or like to theorycraft a bit with me feel free to post about it.
This guide may not be colorful or flashy but it correct information and well organized hope this helps.