Really bad faction = KoS (Kill on Sight). This really
stinks, as the merchants of Norrath are one tough bunch
(all that elite merchant combat training, methinks).
Some mobs adjust faction in ways you wouldn't think.
For example, aviaks around Butcherblock are loved by
the guards - therefore, you kill enough of them, the
guards take a dislike to you. This is really bad if
you happen to be a dwarf! In beta, bandits would also
adjust your faction negatively towards the race of the
bandit (ask Krys, he killed enough dwarf bandits to
be KoS in Kaladim), which, in my opinion, is wrong,
but that's how it is. Another bad effect was killing
human bandits, which are KoS for most folks, made the
gypsies dislike you, which was a hard lesson when you
traveled all that way just to buy some good weapons.
A general rule of thumb is that if it walks on two legs
and doesn't attack on sight, it probably has a faction
hit to it. This seemed to be pretty true for me throughout
beta. Of course, wolves and bears kill your faction
with those tree-lovers in Qeynos, so it's not an absolute.
If your uncertain and don't want to risk poor faction,
then do what I do: if it's a 2-legger and it doesn't
attack you, don't attack it.
One of the great things about Norrath is that not everyone
is gonna like you, no matter what - so don't sweat it
too bad. Your race or class alone can make some folks
hate you no matter what you do. Try to avoid these characters
when selling items, however, since your goods will fetch
higher prices when selling items to those with whom
you have a good faction standing with, such as those
within your class's guild.
In P3, debug code was in place that displayed what kind
of faction hit you were taking for killing a mob. This
usually helped only to determine if a mob was a free
kill (no penalty), or if somewhere, something hated
you just a bit more because of the kill. While this
code has been taken out, some mobs
will give a hint to what your faction hit is by their
dying sentences. When you kill a Crushbone orc, and
the last thing he spits at you is "You'll have all the
Crushbone orcs after you", you can be sure that's a
faction hint. So don't ignore those words - they play
an important role.
Finally, the way to determine another mobs attitude
towards you is with /con. Here's a quick rundown:
XXXX scowls at you, ready to attack. [REALLY hated]
XXXX glares at you threateningly [hates you, but *might*
not attack if you don't hang around too long]
XXXX glowers at you dubiously [won't sell to you or
talk with you except insults, but won't attack either]
XXXX glances at you apprehensively [you aren't their
favorite person, but they will sell to and deal
with you]
XXXX regards you indifferently [just what it sounds
like]
XXXX regards you [they like
you]
XXXX regards you warmly [they REALLY like
you]