FINISH WHAT YOU STARTED
Finish what you started simply means, don’t hit another monster, when the previous one isn’t dead. A wounded monster still hits as hard as a healthy one. Just finish the monster you started with first, then move on to the next one.
RETREATING
Don’t think retreating is for cowards only; it’s NOT! If you don’t retreat while too many monsters are heading your way, you’ll probably get killed. Retreating is the best thing you can do when too big a force is heading your way. Not all monsters will follow as far as the others, and thus the posse will scatter into smaller groups, which you might be able to handle. Retreating to strategic points like doorways and obstacles is a very wise thing to do. Don’t be ashamed, be proud you're not one of those morons who prefer to stay and die. If the monsters are way too strong for you, watch out you don’t retreat to corners; retreating a second time will be nearly impossible because you're stuck in a corner.
THE WAY BACK
If you get surrounded by monsters, kill the ones first that block the way back. This way you can always retreat when you want to.
BLACK DEATHS
Watch out Black deaths (those yellow radio-active zombies) don’t hit you. “Why not?” Because each time they hit you, they steal one hitpoint PERMANENTLY! Kill them from a distance with your arrows or spells like holy bolt. If they still manage to come too close. retreat or leave the game (on time!) In a level with black deaths I advise you to stay away from the wall when going around a corner. This way when one is immediately around the corner you have still time to kill it before it reaches you.
(This picture was taken on nightmare difficulty. The black deaths were able to come so close so I would have more than one of them on this picture. I advise you to kill them from as far away as possible.)
SHRINES
Only touch shrines you know the effect of (the effect itself has to be good of course.) So never ever touch a goat shrine or cauldron! You never know which effect they have, so don’t touch them! Avoid fighting near cauldrons and goat shrines; you might accidentally touch one. It happened to my warrior twice! One time the effect was harmless, the other time I lost 9 mana PERMANENTLY!!! And I already had so little mana. So watch out for them!
READING GLASSES
When you play with a Warrior or a Rogue, or Sorcerer whose magic isn't that high, keep reading glasses. Reading glasses are items that increase your magic, but which you don't have equipped. When you find books that you can't read, go to a safe place, equip the items (the reading glasses) and read the book. After reading it, put back on your normal stuff.
RE-ACTIVATING
Re-activating looks a lot like retreating. It’s a bit different than the normal retreating though(where monsters can follow.) When you accidentally activated way too many monsters, get out of there as fast as possible. The fastest way is to use teleport multiple times. This way the monsters can’t see you anymore, and will stop. You de-activated the bunch. Now go back, but very slowly! This way you’ll re-activate just a few monsters of the pack again, and not the whole bunch. Now use the normal retreating method; retreat to safe ground, preferably safe ground with strategic points. Kill the monsters there, and go back again (very slowly!) Re-activate some more, and retreat again. Repeat as often is necessary.
HIT THE WALL WITCH!
This is a tactic I use the most when fighting with my rogue with the bow setup. It looks like something between retreating and the peek-a-boo tactic. When I fight against witches (who follow when I retreat) I retreat around a corner (a few steps away from the corner itself.) The witches then appear, but they will stop as soon as they see you again. (Most of the times that is!) They will shoot, but will hit the corner (as you can see on the picture.) I can hit them though, and thus kill them without getting hit. Sometimes a witch takes a step more, and can thus hit you too (this mostly happens when you activated a lot of witches.) In that case kill the ones that can hit you first.
SUCCESSORS MUST WAIT
Kill the monsters without a successor or with the least successors first. This way you’ll decrease the amount of monsters facing you. The only exception of this rule is when a monster with more successors blocks the way back. (You should prevent this though.) On the picture below you should kill the one on the right first, since nobody will replace him. If you do this you will face only one blood knight. The one behind him will wait.
TRAFFIC LIGHT OF FIRE
This is a recent discovery of mine. It is an extremely powerful strategy for those of us who play melee characters. Especially if you’d like to do a 1@17, 2@20, or 3@30, or just have a hard time in hell, you had better read on.
I call this tactic the “Traffic light of fire.” It only works (as far as I’ve tested it) on Vipers and Knights that are not immune to fire. It also works on Diablo himself. (I thought it would also work on Lightning demons, but Deebye proved me wrong there.) When you find some (non fire immune) vipers and or knights in a level, retreat to a place less broad than your firewall. (Like hallways and entrances.) Throw ONE (!!!) firewall immediately and straight in front of you (between you and the monsters to be precise.) Then wait till the monsters arrive. Only one will enter the firewall, the rest will wait till he’s dead! Once he’s dead, only one will replace him! (They want to walk around your firewall, but they can’t since both ends of the firewall touch a wall.)
There are only two conditions to make this tactic work:
1) Don’t move! If you move the monsters will leave the firewall! Use the shift key to prevent yourself from moving when swinging your weapon.
2) Throw only ONE firewall directly in front of you! If you stack the firewall directly in front of you, the monsters will leave the firewall!
(Picture above shows how the Blood Knights wait till their companion has died. Only one shall replace him.)
That’s all there is to it! It could be done more effectively though! Point 2 says you may not throw two or more firewalls directly in front of you. You may throw firewalls behind (!!!) the first firewall though. These firewalls may be stacked. (It’ll be more effective to stack those.) Watch out though, you don’t accidentally throw a firewall on the first firewall! If you cast these additional firewalls (behind the first firewall) when the monsters are already present, they will burn while waiting for the one in front of you to die. Even if the second, third, etc row of firewalls are stacked, they will remain in it, till the one in front of you (in the single firewall) is dead.
If you’ve thrown the firewalls prior to the arrival of the monsters, one monster will enter the first (and single (!!!)) firewall, one will enter the second row, one the third etc. If there are more monsters than rows of fire, the rest will wait behind the last firewall. When the one in front of you has died (green light ;-) all will move one step forward, and burn again.
(Picture above shows the real traffic light. If a monster dies, the ones behind him will take one step forward. Then they wait for the next one to die.)