[MUD-Dev] Gamasutra: Online Justice Systems

Koster Koster
Wed Mar 22 09:49:37 New Zealand Daylight Time 2000

My friend Derek Sanderson wrote an article for Game Developer quite some
time ago on methods of handling playerkillers in a commercial online world.
Gamasutra just posted it. It's out of date in the following respects but
still interesting.

- EQ has shipped by now, of course.
- EQ now has "PVP only" servers. Some of said servers are team-based PvP and
one is free-for-all.
- AC uses a system exactly like EQ's, down to the PvP server thing.
- UO has added longer-term consequences. There is now a long-term murder
count and a short-term one. Both increment upon a kill being reported. One
decays away at 8 hours, the other much slower. Losing stats upon death is
determined by the short term count, being red and therefore attackable is
determined by the long count. Lastly, there's also a "ping pong" count which
increments each time you go from blue to red. It does not decay--do this too
many times and you are forever red.
- UO is about to go to having very large -PvP areas via doubling the map.
- Derek isn't at Simutronics anymore. :)


Quoted here so that it sticks around in the archives:

start quote--->
Online Justice Systems
by Derek Sanderson

A Few General Guidelines
In order to build a successful online game, you must build a sense of
community among your players. One of the biggest challenges to successful
community building in online role-playing games is tempering the problems
caused by players killing or stealing from other players. Such problems are
known more generally as player-vs.-player conflict (PvP). Over the course of
time, different games developed by different companies have sought to
control this problem through a variety of methods. This article touches upon
PvP control strategies used by Simutronics Corp., where I am currently
employed, as well as strategies used by Origin Systems in Ultima Online and
by 989 Studios in its game Everquest. While there is no single correct way
to maintain order in an online game, by examining these companies'
strategies for restraining nonconsensual PvP, I have created a set of
general guidelines that should be considered when designing an online
justice system.

The Current Methods

While existing systems for controlling PvP show some very creative design
solutions, each of the following strategies nonetheless suffers from certain
flaws that arise from the different priorities assigned to game play

Administrative Control (Simutronics' Gemstone and Dragonrealms) Simutronics
gives its players wide leeway in resolving conflicts among themselves, and
generally limits its hard-coded restrictions on attacking other characters.
New players may not be attacked and are not strong enough to harm one
another. Stealing from a person's inventory is limited to coins and small
gems, and corpse looting is either not possible (as in Gemstone III) or has
safeguards that allow careful players to prevent it from happening (as is
the case in Dragonrealms). The leeway afforded the players allows the
responsible players a great degree of freedom in how they play their
characters. To balance out this freedom, though, Simutronics strictly
polices its player base. Its players' terms and conditions agreement, for
example, states, "What is not acceptable is to initiate combat against
unsuspecting victims. Anyone exhibiting such behavior, especially one who
chooses to prey upon weaker players for his or her own enjoyment, may be in
violation of...policy."

Dragonrealms' rogues' gallery. 

"Unsuspecting victims" can be a difficult standard to enforce. It's fairly
obvious when someone is on a mass-murder spree, and we remove such
characters from our games immediately. If the offender is an experienced
player who knows better, we generally penalize the account with official
warnings and restrictions from playing for a period of time. If the player
is new to our game, we explain our policies. If any player is unwilling to
abide by the rules, Simutronics usually recommends that he or she try a
product better suited to his or her tastes.

Simutronics' methods are effective for controlling those players who
understand the rules and deliberately choose to violate them. The system's
main weakness, however, is in handling conflicts in which the two parties
disagree over whether consent to violence was given. For example, if player
A makes a few choice comments about Player B's suspected lineage, and Player
B attacks, is the conflict consensual? Some Simutronics staffers would say
consent was implicit in the insult, but others consider consent to be
something that must be explicitly stated by the victim prior to any attack.
When staff tread such nebulous ground, they're fighting a battle that is
impossible to win. No matter how they handle the conflict, their
intervention often creates hard feelings among the players. Resolving these
squabbles also uses staff time that could be spent on game development,
requiring a higher developer-to-player ratio than would otherwise be
necessary. Simutronics has made the choice to incur these higher costs in
order to maintain games in which our customers may play in relative safety
from arbitrary attacks. Whether such a solution would be viable in another
game depends on the developers' goals and budget.

Player Policing (Origin Systems' Ultima Online) Ultima Online's developers
decided to forgo administrative policing and leave its justice system
entirely in the hands of the players. Raph Koster, Ultima Online's lead
designer, said Origin designed the game this way in the hopes that, "given
the tools to police their own environment, [players] would do so.... Our
experience was that every method of administratively imposed policing either
failed or led to intense resentment of the administrators of the game. We
were particularly concerned because traditional models on MUDs for enforcing
social mores were very administrator-intensive, requiring a large number of
skilled administrators willing to devote a lot of time to soothing ruffled
feathers on the part of players who felt wronged. In a commercial venture of
a large scale, we didn't think this was sustainable."

Allowing your customers to police themselves is a noble goal, but one that
is difficult to implement. The most infamous result of the Ultima Online
hands-off policy was the gangs of player killers (PKs) that formed. Such
gangs would station themselves at key locations in the game and ambush any
poor soul foolish enough to travel with a group smaller than a mob. "I just
got PK'd," was a refrain commonly heard outside the game's banks, where
naked adventurers would come to beg for money to re-equip themselves. Some
players formed anti-PK militias, but, as Raph says, they were "inadequate
for handling the problem of player killing. The actions of the few police
were both insufficient in quantity and inadequate in severity to curb the
activity of the player killers and the player thieves."

An innocent is attacked in Ultima Online 

In response to the problem, Origin instituted a variety of tools to allow
the players even greater control over their environment. Under the current
system, all characters begin the game flagged as "innocent," with their
names highlighted in a bright, happy blue. Steal from, attack, or loot the
dead body of an innocent - including an NPC - and your character's name will
be highlight gray, branded a criminal and open to attack by anyone. Kill an
innocent player character, and that person is given the option to report you
as a murderer and place a bounty on your head. Kill five or more innocents
in a short period of time, and your character is flagged a "murderer,"
unable to use shops or access your bank account, and subject to being slain
on sight by other adventurers who wish to collect the bounty on your head.

Ultima Online's facility for reporting crimes. 

Ultima Online's greatest strength is that it places administration of PvP
entirely in the hands of its players, giving them an unrivaled sense that
they, and not the Origin staff, control their world. The benefit of this
feeling among players shouldn't be underestimated; it's a powerful
contributor to a sense of immersion in the game environment. The system is
weak, however, in controlling random aggression. Only after five reported
kills does PvP activity have any real repercussions for the aggressor, and
the game does little to track long-term aggressive behavior. If a player
waits just eight hours of online time between murders, he can kill one
player a day without ever reaching the murderer threshold. No penalty exists
(other than being flagged a "criminal" for a short period of time) for
attacking someone unless that person dies as a result of his or her
injuries. Harassment attacks that fall short of a murder are still extremely
common in Ultima Online. I was, for example, attacked by total strangers an
average of once a day over three weeks of playing while writing this
article, and killed three times. (Note to game designers: other game
designers get really grumpy when your players kill them, especially when
their colleagues make fun of their poor fighting skills.)

Player-toggled Flags (989 Studios' Everquest) The developers of 989 Studio's
Everquest implemented a flagging system that will mark characters either as
able to attack and be attacked by other players (+PK), or completely unable
to engage in such activities (-PK). The method is a common one for
controlling violence in small text-based MUDs, but my experience suggests
that in a large-scale game, where the community is of sufficient size to
allow true anonymity, the use of "throwaway" (also known as "mule")
troublemaker characters with -PK flags will abound. Such characters, immune
from physical harm, can do many nonviolent but extremely annoying things to
other players, such as following another character around wherever he goes,
blocking entries to important areas, attacking monsters other players are
already fighting, engaging in verbal harassment, holding goods stolen by +PK
characters, running cons and scams, refusing to leave someone's home, and

Brad McQuaid, Everquest's producer, says his team is aware of the PK flag's
potential abuses and is prepared to combat them. The game will have a
squelch command to combat verbal harassment, and out-of-context
(non-role-played) harassment will result in punitive measures against the
offender's account. As for killing the creature another person is fighting,
Brad says, "...the player or group that does the most damage to an NPC gets
to loot it and receives the experience for the kill. This stops the jerk who
comes along and gives the killing blow to a creature even though another
person or group had engaged the NPC long before. He's welcome to deliver the
killing blow, but he will receive no experience for doing so."

In Everquest, players who wish to attack other players must be flagged +PK
and even then
can only attack other +PK characters. 

The general principle behind the Everquest kill-stealing prevention is
sound, but what does one do about the high-level, -PK player who goes to a
low-level hunting ground and steals kills repeatedly, doing more damage to
creatures than the new players fighting them by virtue of an incredible
advantage in skill? Does one block entry to such areas for high-level
players? Does one prevent high-level players from attacking low-level
monsters? Does one simply warn the player for disruption? The number of ways
to get around the game design illustrates the greatest danger to the PK flag
solution, namely that it creates an invulnerable subclass of character that
players will be unable to police, thus shifting the burden (read: increasing
staffing costs) to the game administrators. However, I suspect the flagging
solution will be popular with a significant portion of Everquest's customer
base, because it allows responsible players who don't enjoy PvP to play
without interference from their more aggressive cohorts.

A Few General Guidelines

If the perfect solution has yet to be implemented, then what is the answer
to managing PvP? A complete system design is beyond the scope of this
article, but here a few things to be considered when designing an anti-PvP

Reduce overhead by minimizing staff intervention in player affairs.
Minimizing staff intervention in player affairs is a principle that should
be followed across all aspects of your game design, and it's particularly
true for your game's PvP controls. Players will always exploit loopholes in
your design to their advantage, and when they do, the best way to resolve
the problem is to alter your code to prevent the undesired activity.

A good example of players using a system contrary to its intended design is
the process by which a character of the cleric class may resurrect another
character in Dragonrealms. When a character dies, a counter starts tracking
skill loss, and the longer a character has been dead when resurrected, the
larger the loss will be. Clerics are able to cast a Soul Bond spell that
will neutralize this skill loss, and players generally expect that a cleric
will do so before performing the resurrection. In the early implementation
of this system, however, players used the process to force skill loss by
intentionally resurrecting characters without first casting the Soul Bond

Although the system mechanics allowed such activity, it didn't fall within
the behavior expected by the staff, and several clerics had their ability to
cast the spell temporarily taken away for abusing the loophole before we
coded changes to close it. Although our intervention took care of the
immediate problem and made the victims of the aggression happy, it tended to
make the players against whom we took action resentful. A pattern of such
staff interference can result in an antagonistic relationship between your
customers and staff and increased expenses to cover the lost development
time spent correcting player behavior. It can also foster an environment in
which players expect staff to handle their disputes, generating an
ever-increasing number of assistance calls as your customer base grows.
Whether you are willing to pay such costs is up to you.

Bounty available for the heads of 
Ultima Online criminals. 

Make all methods of PvP reportable to a hard-coded justice system. Players
should be able to report all forms of PvP to the game's justice system.
Possible methods include presenting murder victims with a pop-up window,
such as the one Ultima Online display, or allowing players to file
complaints with NPC guards or magistrates. Whatever the reporting mechanism,
it's important to include all forms of PvP, such as theft, corpse looting,
casting offensive spells, being harmed by an area-effect spell, being
attacked with a weapon, being killed, or having player-controlled NPCs or
creatures perform any of these offenses. The reporting mechanism should be
intuitive and easily accessible, but should involve some effort on the part
of the reporting player so only the truly important attacks are reported.

Extra care must be taken with area-effect spells. (Area-effect magic spells
affect all characters within a certain radius of the character who cast the
spell.) A common player-killer tactic in Ultima Online is to enter someone's
area-effect spell deliberately, then kill that person after the system flags
them as "criminal" because of the damage the spell causes to the
player-killer's character. If you cannot detect such behavior with your
code, possible solutions are either not to design such spells or to make
them non-harmful to other player characters. You'll lose a bit of realism,
but the loss will be vastly offset by your closure of this common PvP

Another area of special attention should be your PvP theft-detection
mechanism. Here's an all-too-common scenario: Character A has a pocket full
of coins, and encounters Character B. Character B steals the coins from
Character A, but Character A fails his skill check to notice the theft
attempt. The person playing Character A, however, notices the coins are
gone, and draws the very reasonable conclusion that they were stolen by
Character B. Under most game systems, however, Character A has no recourse,
and will be labeled criminal if he attacks the thief in an attempt to
recover the money. Such thefts are generally the most frustrating for your
customers, because the person playing the thief will often use his immunity
to taunt his victims. The solution is to allow the victim to report anyone
to the justice system, with penalties for false accusations.

Make anti-PvP systems activate only upon player request. Only the victim of
an online crime truly knows whether the actions against his or her character
merit a reaction by the justice system. The person who harmed the character,
for example, may be engaged in a friendly duel, or the violence may be a
role-played conflict that the victim wishes to avenge personally.

Ultima Online has an excellent implementation of player-initiated justice,
although it contains a few loopholes. If one attacks an innocent, for
example, one is automatically flagged "criminal," even if the attack were
accidental or entirely consensual. A character of mine was once killed and
looted by a stranger for being "gray" (indicating criminal status) after I
accidentally hit a companion while in combat. My killer wasn't impressed
with my explanation, and I signed off that day much poorer than when I
began. If I'd been murdered as "innocent," however, I would have been able
to report the attacker and place a bounty on his head.

Ultima Online also has a way to remove players entirely from the justice
system if they are members of a player-run guild. The guildmaster of a guild
may issue an official declaration of war on another guild, and if the
declaration is reciprocated, the two guilds enter into a state of conflict
in which members may attack, kill, steal from, and loot each other freely
without becoming criminals. A second level of warfare offers even more
uncontrolled PvP conflict. When a guild's leader becomes famous enough, he
or she is given the power to declare the guild an Order or Chaos guild. Upon
doing so, the guild enters a state of perpetual warfare with all guilds of
the opposing type, and members may fight with opposing guild members at any
time, anywhere. "This provides the 'ambush around every corner' feeling that
this type of player values," says Raph. "The warfare system proved to be
very popular, with 10 percent of guilds converting over to the
'free-for-all' guild type as soon as it became available."

Ultima Online's guild system allows a 
sort of regulated PvP. 

In Everquest, those characters who are flagged +PK will be able to attack
and kill other +PK players at will, but a hard-coded race and alignment
system will determine how the rest of the world reacts to the slaying. A
player-character ogre, for example, is from a classically evil race. If that
ogre kills a player-character elf, which is a classically good race, the
ogre will, says Brad, "[when] he returns to his home town, be welcomed as a
hero.... In this sense, player killing is encouraged in Everquest where it
makes sense." However, if elven guards observed the ogre attacking the elf,
they would likely intervene. Furthermore, a character that kills members of
his or her own race would eventually find NPCs of that race reacting poorly
to the character.

Make revenge an option. This section merits an entire article in itself, so
I'll mention it only for completeness and keep my comments brief. The key
idea here is that many players would prefer to fight back when subjected to
a PvP attack and wouldn't enjoy reporting the activity to an NPC system.
When a character is the subject of aggression, the aggressor should be
flagged so the victim may fight back without penalty, whether it be an
immediate response or a later ambush. Ultima Online has implemented this
principle by flagging an aggressor attackable for two minutes per attack. My
experience suggests that this isn't enough time; for me, at least, my
initial reaction to an attack was to flee to heal myself. By the time I'd
recovered from the initial ambush, my aggressor was usually no longer
eligible for a penalty-free attack.

Make PvP much less profitable than player-vs.-game activity. A certain
percentage of those who kill or steal from other players do so simply
because player-characters tend to be far more wealthy relative to the level
of danger they present than NPCs or creatures. Take away the profit from
PvP, and you'll curtail a certain percentage of it. Ensure a stable supply
of player-vs.-game activity, and you'll decrease it even more.

The most obvious way to lessen the profitability of player-killing is to
restrict looting of dead characters, without removing the ability for
players to help their fallen comrades. One method is to prevent looting
entirely, although a corresponding mechanism must be created to allow
recovery of stolen items if a thief is tracked down and slain. Another is to
allow looting only under specific circumstances. Ultima Online flags looters
as criminals, making them vulnerable to attacks or having the NPC guards
called to execute them.

Everquest had not yet finalized its corpse-looting restrictions at the time
I wrote this article, but Brad says that the developers are considering
several options. "...If you are -PK and you die, only you or someone to whom
you give consent may loot your corpse. If you are +PK and come across the
corpse of another +PK character, you currently are free to loot it. We are,
however, experimenting with some limitations to make player killing more
viable. We will test a system in which the killer may loot his victim only
once, and may take only one item of choice from the corpse."

If you implement such restrictions, provide enough monsters or NPCs to meet
player demand, and give players enough wealth for them to feel they are
making reasonable progress, you'll drive player activity towards the
monsters. Make your monsters and NPCs too poor, or fail to spawn enough of
them, and your players will turn on each other. Similarly, it's important to
give player thieves enough creature or NPC targets to make the class
economically viable, else a percentage of those who would normally only
steal from non-players will turn to PvP stealing.

Restrict the ability of new characters to harm others. Players will always
use system loopholes to maximize their gains, and if a new character is able
to accomplish a highly dangerous task and realize the same gain as an older
character, then the use of the aforementioned throwaway characters will
abound. This is especially true when more than one character is available to
the customer on the same account, or if free trial accounts are accessible
to the players without the purchase of a retail product.

Stealing and scamming are the most common uses for throwaway characters, and
is usually accomplished in a way that circumvents the system's intended
design. In Dragonrealms, for example, throwaways are frequently created to
loot weapons dropped on the ground by dead adventurers. The throwaways then
pass the weapons through friends and back to the main character on the
thief's account, disguising the true identity of the thief and making
redress impossible. Throwaways also exploit loopholes in our
player-to-player item exchange mechanisms, tricking adventurers out of their
goods and then passing the profits to the real character on the account.

Simutronics is not alone in facing problems with throwaway characters. One
common trick in Ultima Online used to be for two players to create thief
characters, stand near a bank, and steal items from adventurers. If the
victim detected the theft and called for the guards, the thief was executed.
The thief's partner would then lift the item from the dead body, and the
original victim would have no way to get it back. Origin recently fixed this
exploit by having the guards return stolen items to the victim if the thief
were killed within city limits within two minutes of the theft.

Charge players for PvP activity in a currency that is valuable to them. When
an activity has a perceived cost, the frequency of that activity will always
decrease. It's a basic supply-and-demand formula; make PvP more expensive,
and fewer people will choose to purchase it. Those who choose to engage in
PvP activities will therefore have to decide before every assault whether
they are willing to pay the price. Scale the cost of that activity as its
frequency increases, you'll prevent repeated abuse by older, richer players.

You could, for example, make the tax a monetary one, and charge an aggressor
25 coins for his or her first reported murder, 50 for the next, then 200,
400, 800, and so on, allowing the character's criminal past to decay one
fine level per week if he or she refrains from all criminal activity.
Characters who are unable to pay the fine could be restricted to a debtors'
area from which they couldn't leave until they had performed enough
low-paying menial tasks to pay off their debts. Preventing someone from
leaving until their fines are paid would stop savvy players from offloading
their valuables onto storage characters before going on a killing spree;
allowing them to perform work to escape would prevent anyone but the worst
cases from being trapped inside.

A tax doesn't have to be a monetary one. A character could, for example,
lose an increasing number of experience points or skills with each
subsequent PvP report against him. If he or she reaches a certain threshold,
that character would be hit with a curse that prevents all aggressive
activity for extended periods of time. Another possibility would be to toss
characters in a jail cell for increasing periods of time, where they must
stay until their sentences are served.

Whatever you choose for your tax, the penalties should start at negligible
levels and scale up exponentially rather than linearly. Low initial
penalties, when combined with a slow decay of criminal histories, will allow
new players to learn the system, allow all players to make the occasional
mistake, and allow normally law-abiding characters to take the occasional
swing at someone who really, really deserves it. Only those who try to make
a career of harming other characters without their consent will be subject
to heavy fines.

Balancing Good and Bad

There is no magic bullet solution to solve all of the PvP problems inherent
to an online role-playing game community. No matter what methods one uses,
players will always find ways to harass, pester, and annoy each other, so
trying to eliminate all forms of aggression isn't a realistic goal. If,
however, you give proper reporting tools to the victims of non-consensual
PvP, allow players outlets for consensual attacks, and make everything else
costly, you'll find the problems reduced to manageable levels. There is room
for all styles of play in a properly designed role-playing game, and finding
the correct balance is key.


I wish to extend a special thanks to Raph Koster and Teresa Potts of Origin
Systems, and to Brad McQuaid of 989 Studios for their timely assistance.
This article would not have been possible without them. Thanks also to
Simutronics designer Emily Jacobson for her ruthless editing.

Derek Sanderson has held several design and customer service positions
during his tenure with Simutronics, and has recently settled in as the
company's lead designer. He is currently pondering the career ramifications
of commuting to work in a go-kart, and welcomes input on this subject at
rpgvault at aol.com.
<---end quote


MUD-Dev mailing list
MUD-Dev at kanga.nu

More information about the MUD-Dev mailing list