Pk is a major part of Medievia and can be affected by many things. One of the most serious aspects is alignment. I tend to focus on pk as a cleric. One of the most unsual classes for pk, however one of the most capable by far. Most players on med tend to remain evil alignment due to equipment. As good align it may difficult to achieve extreme stats, but it is overlooked how easy it is to get decent stats. Pking as a cleric is dependant on 2 forms of attack, harm and hammer of faith, and defense is dependant upon 4 main forms: Protection from evil, Protection from good, Sanctuary and Fireshield.
On the offensive end your attack should be based on your alignment, as well as your target's alignment. If you are 1k and your opponent is -1k, you should naturally use hammer of faith, you will do massive amounts of damage, and will offer no saving throw to your victim. Same goes if you are -1k and your target is +1k. As a note to evils do not use demonfire, it tends to do less damage than harm and is really a rather useless attack spell. Anyhow the offensive strategy comes in when you are of similiar alignment. You should only use hammer of faith if the message you receive is "You devastate" or better, other wise harm will do more damage, and cost signifigantly less mana to cast.
Timing is probably the most important of pk as a cleric. Timing is everything. If you are fighting a mage or cleric and he is falling low, you can be just about sure that he will flee, attempting to live. You should never spam spells, the tides can turn in just a single round very quickly, you should instead get the feel of when you can cast a spell each round, and cast only at that time. If this time is near the end of a round, you can often follow and get in the required few attacks to finish them, as flee incurs a slight lag and they will most likely read the exits, taking up valuable time. If you spammed you will sit in the room, lagging yourself and leaving yourself extremely vulnerable. As well, if you are fighting a thief or multiclass warrior you can be sure they will flee, and attempt to return and deliver a crushing backstab. If your timing is on, you can follow any person I would say around 70% of the time. With the constant fleeing, and inability to attack, the said opponent will be inflicting little damage while sustaining constant damage.
To defense, but of course. I usually determine defense by once again
heading to alignment. If I am fighting an opponent of opposite
alignment I will use protection from
Now when I am fighting an opponent of equal or neutral alignment
I will usually use sanc, as nearly any triple backstab through
fireshield will kill anybody. Will most likely just follow the
basic attacking techniques I mentioned earlier, though a cast
of fireshield at the perfect time can be one of the quickest ways
to ensure a victory.
This is very true when fighting a victim of opposite alignment,
who is using backstab as his primary offensive tool. You can be
pretty sure your target is going to flee,scan, and then type the
direction and backstab together, often failing to correctly react
to a backstab. This can be devastating. With protection on you will
inflict several hundred points of damage, assuming it was a backstab
of decent power, and then your victim will be just sitting there for
3 rounds. If you time a fireshield to be cast right after your target
flees and looks to return his bs, you can often achieve a kill in
this time period, as this is assuming you have already inflicted at
least 3 rounds of damage..
Over time, everybody will develop their own strategies and tricks.
This is just an overview of what I have personally learned and found
effective over the years. Best of luck.