Leveling Hardcore characters is no joke, because
obviously you need to be careful every step of the way.
This guide should help give you some pointers on how to
level your hardcore characters quickly!
Here is a basic strategy I have used myself with great
results with many hardcore characters so far:
I do the following:
1) Start with some +xp gear with no/low level
requirements in stash.
2) Level with this gear straight through Act I normal
(end ~level 15) to Act II Maghda, upgrading from
stash/AH with better +xp gear and weapons as I can.
3) Once I've killed Magdha, I do the quest to kill her a
few times till I'm 22-23.
4) Then, after a few upgrades, I quest until I've killed
Kulle (Soulstone Chamber quest).
5) Run Kulle (more info below) from 24-30 (takes about
1-1.5 hours solo, 2 if you're slow and spend some time
on the AH in between).
6) Run Act 3 straight through, should get you to 32-34.
If things get too hard, repeat some of the easier quests
and/or spend some gold at the AH.
7) Run Act 4 straight through. (Should finish at 34,
maybe 35)
8) Run Act I NM until Wortham.
9) Repeat Wortham NM until level 40.
10) Run Act I NM from Wortham until Butcher (should get
you through 41).
11) Run Act II NM through to Maghda NM (level 42).
12) Repeat Maghda 42 -> 45 (or whenever you're ready for
Kulle, HP should be around 12-15k, can be lower if
you're awesome).
13) Run to Kulle (45), repeat until 50.
And that's where I am now. I've done this or a subset
with every class so far, and haven't lost a character
yet.
After Act 2 NM is where things get interesting I hear,
but I imagine questing straight through from 50 to Act I
Hell Wortham, and then repeating that until 60 or close
to it.
Continuous Farm Runs
One thing that I highly recommend doing with hardcore
characters is farming the same spots over and over
again. The reason why is because you will know what you
are up against, and you will know what you will need to
do to clear the mobs out, and it is extremely safe to
level a hardcore character quickly.
Zoltun Kulle Run:
For
example, Kulle running IMO is a great farm run for
hardcore characters:
What you need:
A friend with a character (preferably a Demon Hunter)
that can run Kulle with ease in seconds.
1) Friend makes game on the Kill Zoltun Kulle quest
point and enters game.
2) Once in-game your friend takes waypoint to Kulle and
enters his room. (Demon Hunter is good because vault
with sprint passive makes running fast to portal).
3) Now he whispers you "ok" and only now can you join
the game (enter before and you cant skip the 'join boss'
popup).
4) Wait in town and hand in the quest to Adria when
done.
5) Both leave, repeat as many times as you wish.
It takes between 4-6 runs per level past the first
couple, but I timed our runs at only 1min each. I went
from 1 to 22 in maybe 65 mins. Definitely faster than
questing through.
You also get just over 1k gold per handin so you can
make 60k easily as you boost up.
Other good farm/XP
runs:
-Wortham is another good run for hardcore characters.
Wortham gives 20k as quest reward, and about 10k from
the mobs if you're not too over leveled.

-The "Lieutenant Vachem" under "Road to Arcanus" in Act
II. Take waypoint, go in cellar, Talk/Fight Maghda,
leave cellar, help Iron Wolves kill hidden guards. Takes
about 2 minutes each time and worth a decent amount.
-In Act I, not sure about exact place. I just call him
the crazed weaponmaker. Help him out. Get XP, but be
careful not to step to next waypoint. He doesn't always
spawn either, so just exit and restart if he isn't
there.
-In Act II "Unexpected Allies" is relatively safe and
good experience.
-The Maghda fight. A bit more XP than Alcarnus but takes
longer.
-I find the first two quests in A3 (lighting signal
fires and raising catapults) is pretty good too, and
since it takes a while you do not get so insanely bored
and you usually get a few rares per run.
Learn to safely escape
when in trouble
Hardcore in D3 is incredibly more difficult than D2. I'm
not even talking about the monster difficulty. Blizzard
basically took away the safety net:
- no escape+exit to get out of jam
- no more spamming potions/rejuvs to keep your health
up.
- no town portal escapes.
The time delays on all the above makes hardcore mode
feel impossible when you get in over your head. Now your
only solution appears to be to somehow stop/slow enemies
as you try and runaway. Especially as a wizard this is
quite difficult. Tell me it's easier when you get
Teleport :) I haven't had a chance to try it yet to even
see what types of limitations that has. My last wizard
died just before reaching this skill.
Here are some safety tips for Diablo 3 if you fear you
will get close to dying:
-Always make sure you wait for your escape abilities to
complete cooldown before engaging in battles.
-Never run into unexplored areas. Keep an eye on the map
and run back in the direction you have already cleared.
Run all the way back to the last waypoint if you have
to.
-Use defense abilities! But don't be too
defensive. You have to have damage and hitpoints too!
Killing quickly is just as important as having a high
HP.
Lastly, studying professional hardcore strategy guides
for Diablo 3 would greatly help your chance of living.
Diablo 3 Billionaire provides these guides and more.