I like to know stuff. Googling of "player killer servers" produced this(and, yes, it's nerdier sounding than I thought):
Overview
Some versions of Ragnarok Online have special servers in which Player Killing (or PK) is allowed in certain maps outside of PvP. The original kRO server of this type is called Urdr, and some services also named their PK servers the same. For information on which services have PK servers, see Servers. Although popular in past years, PK servers have been gradually phased out, concurrent with the introduction and growth of F2P servers.
PK Server Rules & Mechanics
The rules and mechanics vary between different versions of Ragnarok Online, particularly which maps are set to PK. The following rules are examples only and may not exist on your server.
Experience and Drop Rates
On a PK server the experience and drop rates are modified from that of a regular server. Base Experience and Job Experience gained is doubled that of a regular server. Drops are increased by 1.5 times.
Death Penalty
On a PK game server, the experience lost when you die is increased. If killed by a monster, your experience drops by a random amount between 1% to 3%. However, if killed by another player (finishing blow), you lose between 3% and 5% exp.
PK Maps
Any map that is not directly adjacent to a city is considered an open PVP zone. Several exceptions exist; Wild Roses (1n 1w of Geffen) and Mi Gaos (1 map south of Louyang) are considered PVP fields.
Who Can PK
Not all characters can fight other characters. Players can only be attacked or attack other players once they hit level 61, or change to second class, whichever comes first.
Warp Portal
Any map that is considered a PVP zone cannot be memorized for use with Warp Portal. In addition to this, marriage recall skills cannot be used on these maps.
Teleport and Fly Wings
The skill teleport (any level) or fly wing items cannot be used in a PVP zone. In addition, the Rogue skill Snatch will not cause teleporting on these maps. However, butterfly wings can be used to return to your save point.
PK Points
Gaining Points
Each player on server begins with 0 PK points, and can gain and lose them based on killing other players (it is possible to have negative points). In a successful player killing, the killer gains one PK point, and the person killed loses 5 PK points. Two conditions are required for this to happen however:
- The killer must not have gained any PK points within the last hour.
- Also, the person who is being killed must not have lost PK points in the last hour.
If the killer has already gained points, or the target already lost points in the last hour, the points of both players will not change. It is also impossible to gain Player Killer points by killing the same person more than once in 24h.
Penalty System
When a player kills another player, they are penalized for their actions. If you kill another player, and you gain PK points for the kill, you are muted for 5 minutes. During this time, you cannot talk, use any skills or any items. It is possible to lose points yourself if you are killed while muted.
Mass Murder System
If you kill one person, you’re penalized, but if you kill many, it can be quite advantageous. If a player manages to gain 100 or more PK points, they’re considered a murderer. As a murderer, the following things happen:
- Your name will show up in red for everyone to see.
- You are given +3 to all stats (+5 if you have 400 points).
- You are given +10% attack and +10% magical attack.
- You gain 10% bonus Discount and 10% bonus Overcharge (to a maximum of 25%).
- When a murderer kills a player, they gain the 3% ~ 5% exp that they lose.
- A murderer gains double experience from killing monsters (so 4x that of regular servers).
Of course, all these bonuses can be lost if you are somehow knocked back below 100 PK points.