# August 2003

- A potential best-seller?
*Richard A. Bartle* - Identifying Players
*Scion Altera* - Identifying Players
*Crosbie Fitch*

- Identifying Players
- Metrics for assessing game design
*David Kennerly* - ADMIN: Crunch thread
*J C Lawrence* - Mapping real money into MUD money
*Alex Chacha* - Mapping real money into MUD money
*Katie Lukas* - Mapping real money into MUD money
*David Kennerly*

- Mapping real money into MUD money
- Mapping real money into MUD money
*Kent Peterson* - Mapping real money into MUD money
*Peter Tyson*

- Mapping real money into MUD money
- Mapping real money into MUD money
*Matt Mihaly* - Mapping real money into MUD money
*Paul Canniff*

- Mapping real money into MUD money
- Research in the Gaming Industry
*Damion Schubert* - Research in the Gaming Industry
*Kerry Fraser-Robinson* - Research in the Gaming Industry
*Richard A. Bartle* - Research in the Gaming Industry
*Matthew S. Ayres*

- Research in the Gaming Industry

- Research in the Gaming Industry
- Mapping real money into MUD-Money
*Henrik Johansson* - Java or LPC (DGD)?
*Ben Chambers* - Java or LPC (DGD)?
*Ammon Lauritzen* - Java or LPC (DGD)?
*T. Alexander Popiel* - Java or LPC (DGD)?
*ceo* - Java or LPC (DGD)?
*Lars Duening* - Java or LPC (DGD)?
*Torgny Bjers* - Java or LPC (DGD)?
*Ryan Underwood*

- Java or LPC (DGD)?

- Java or LPC (DGD)?
- Reputation systems: a possible path for investigation
*J C Lawrence* - Reputation systems: a possible path for investigation
*david.l.smith@mail-x-change.com* - Reputation systems: a possible path for investigation
*Brian 'Psychochild' Green* - Reputation systems: a possible path for investigation
*Andrew L. Tepper*Something related to reputation systems are ranking systems. In a

reputation system, you say "I trust JC, and JC trusts Ed, therefore

I can trust Ed. A good property of a ranking system is that if JC

tends to beat Ed, and I tend to beat JC, then I should tend to beat

Ed.

Both systems are things that players will want to game

(manipulate). We use an algorithm in A Tale in the Desert which has

this property, and is game-resistant. It's described here:

http://www.egenesis.com/erank.rtf

Andy Tepper

<EdNote: Below, minorly reformatted for clarity>

--<cut>--

The eGenesis Ranking SystemA highly cheat-resistant, zero-sum

ranking system for multi player games

Andrew L. Tepper, BS

Josh M. Yelon, PhD

February 15, 2002

Problem:

Ranking systems such as ELO are often used to rate chess

players. These systems attempt to encourage players to compete

against others of a similar skill level by making matches between

an advanced player A, and a beginner player B be risky for A, and

rewarding for B.

In the case that A wins:

A gains a small number of points

B loses a small number of points

In the case that B wins:

A loses a large number of points

B gains a large number of points

These systems are subject to cheating. If a player A wishes to

boost his rank, he conspires with friends B, C, and D as follows:

- B Plays C several times, intentionally losing to boost C's

rank.

- C Plays A several times, intentionally losing to greatly boost

A's rank.

- Another friend D is brought in. The three play each other in

the same pattern to boost D.

- D Plays A several times, intentionally losing to further boost

A's rank.

The pattern is recursive: Players P1 thru PN-1 play each other to

boost PN-1, who then loses to PN.

Solution:

Each player in the system starts with a vector of 256 bits. Half

of these bits, randomly selected, are set. A players rank is the

number of bits set.

We number each bit 0-255. When a match occurs between two players,

A and B, a series of 32 hash values in the range 0 to 255 are

computed based on the players names such that the same two players

always yield the same 32 values. For each value, we inspect that

bit in both players vectors. When a bit is set in the losers

vector, and clear in the winners vector, we transfer that bit:

clear it in the losers vector, and set it in the winners. In all

other cases we do nothing. This system forces players to play a

wide variety of others to boost their rank.

Still, its possible to boost your rank by only playing

beginners. To combat this, we modify the algorithm as follows:

Each player starts with their bit vector clear. They also have 128

reserve bits which are stored simply as a count. A players rank is

equal to the number of bits set in his vector, plus the number of

bits in reserve. When a match occurs, bits are transferred as

above, with the following additional rule: When one of the 32

values bits are clear in both the winners and losers vectors, a

bit is attempted to be transferred from the winners reserve to a

specially selected clear bit in his own vector. This specially

selected bit is based on a different hash function that again

incorporates both players names. The losers vector and reserve are

untouched. In this way, someone who only plays beginners doesnt

affect his own rank, but may boost the beginners rank.

Practical Applications:

We designed this ranking system to be used in massively

multiplayer online games such as A Tale in the Desert

(http://www.ataleinthedesert.com). There are some additional

considerations to take into account.

First, beginners should have the sense that they are making

progress when they first start playing. To resolve this, we report

everyones rank as simply the number of bits set in their vector,

ignoring their reserve bit count.

Second, friends like to play each other repeatedly, and should see

progress on more than just the first game. To resolve this,

instead of attempting transfers for all 32 bits, we randomly

select 8 of the bits to transfer. In subsequent matches won by the

same person, there are fewer bits to transfer, and eventually this

number dwindles to none, but it allows for friends to play each

other repeatedly and still see some progress.

--<cut>-- - Reputation systems: a possible path for investigation
*Matt Mihaly* - Reputation systems: a possible path for investigation
*Vincent Archer*

- Reputation systems: a possible path for investigation

- Reputation systems: a possible path for investigation
- Reputation systems
*Castronova, Edward* - Reputation systems
*J C Lawrence*

- Reputation systems
- Mapping real money into MUD-Money
*Ren Reynolds* - MudDev Faq - part 2
*Marian Griffith* - PHP muds
*Peter Harkins* - PHP muds
*Torgny Bjers*

- PHP muds
- Slashdot story about review of Bartle's new book
*Christer Enfors XW {TN/PAC}* - Slashdot story about review of Bartle's new book
*Dave Rickey* - Slashdot story about review of Bartle's new book
*Evan Harper* - Slashdot story about review of Bartle's new book
*Richard A. Bartle* - Slashdot story about review of Bartle's new book
*Tamzen Cannoy* - Slashdot story about review of Bartle's new book
*Kerry Fraser-Robinson* - Slashdot story about review of Bartle's new book
*Richard A. Bartle*

- Slashdot story about review of Bartle's new book
- Slashdot story about review of Bartle's new book
*Dave Rickey* - Slashdot story about review of Bartle's new book
*Marc Bowden*

- Slashdot story about review of Bartle's new book

- Slashdot story about review of Bartle's new book
- The lack of Creativity and Beauty a game user
*james_nesfield@nesfieldcapital.com* - Artists and Copyrights
*Derek Licciardi* - Artists and Copyrights
*Paolo Piselli* - Artists and Copyrights
*Marian Griffith* - Artists and Copyrights
*Paul Dahlke*

- Artists and Copyrights
- Using Windows Scripting Host
*Owen Matt* - Using Windows Scripting Host
*F. Randall Farmer* - Using Windows Scripting Host
*Karl Dyson* - Using Windows Scripting Host
*Tess Lowe*

- Using Windows Scripting Host
- Better Game Design through Data Mining
*David Kennerly* - Better Game Design through Data Mining
*Chris "Diamonds" Stewart*

- Better Game Design through Data Mining
- When Will Player-Avatar Integrity Be a Feature of Persistent Worlds?
*vladimir cole* - When Will Player-Avatar Integrity Be a Feature of Persistent Worlds?
*Martin Bassie* - When Will Player-Avatar Integrity Be a Feature of Persistent Worlds?
*Craig H Fry* - When Will Player-Avatar Integrity Be a Feature of Persistent Worlds?
*Matt Mihaly* - When Will Player-Avatar Integrity Be a Feature ofPersistent Worlds?
*Michael Tresca* - When Will Player-Avatar Integrity Be a Feature ofPersistent Worlds?
*Baar - Lord of the Seven Suns*

- When Will Player-Avatar Integrity Be a Feature ofPersistent Worlds?

- When Will Player-Avatar Integrity Be a Feature of Persistent Worlds?
- [Fwd: Metrics for assessing game design]
*ceo* - Examine/Look
*Elia Morling* - Examine/Look
*Ammon Lauritzen* - Examine/Look
*Marc Bowden*

- Examine/Look
- Examine/Look
*Lars Duening* - Examine/Look
*Eamonn O'Brien*

- Examine/Look
- [BUS] Account-management systems
*ceo* - [BUS] Account-management systems
*Rayzam* - [BUS] Account-management systems
*Christopher Allen*

- [BUS] Account-management systems
- Job opportunity on Star Wars Galaxies
*Koster, Raph* - NCSoft yearly report
*Mathieu Castelli* - MUD using the .net framework
*Norman Beresford* - MUD using the .net framework
*John Buehler* - MUD using the .net framework
*James F. Bellinger* - MUD using the .net framework
*Linder Support Team*

- MUD using the .net framework
- Virtual property lawsuit in China
*Koster, Raph* - Virtual property lawsuit in China
*Nicolai Hansen* - Virtual property lawsuit in China
*Daniel Anderson* - Virtual property lawsuit in China
*Kerry Fraser-Robinson*

- Virtual property lawsuit in China
- Virtual property lawsuit in China
*Vladimir Cole* - Virtual property lawsuit in China
*Ren Reynolds* - Virtual property lawsuit in China
*Nicolai Hansen* - Virtual property lawsuit in China
*ren@aldermangroup.com*

- Virtual property lawsuit in China

- Virtual property lawsuit in China

- Virtual property lawsuit in China
- Expected value and standard deviation.
*Jeff Cole* - Expected value and standard deviation.
*Scion Altera* - Expected value and standard deviation.
*Jeremy Hill*

- Expected value and standard deviation.
- Expected value and standard deviation.
*katie@stickydata.com* - Expected value and standard deviation.
*Ben Chambers* - Expected value and standard deviation.
*Zach Collins {Siege}* - Expected value and standard deviation.
*Ben Chambers* - Expected value and standard deviation.
*Robert Zubek* - Expected value and standard deviation.
*Kwon J. Ekstrom* - Expected value and standard deviation.
*Eamonn O'Brien* - Expected value and standard deviation.
*Kwon J. Ekstrom*

- Expected value and standard deviation.

- Expected value and standard deviation.

- Expected value and standard deviation.
- Expected value and standard deviation.
*Freeman, Jeff* - Expected value and standard deviation.
*Zach Collins {Siege}*

- Expected value and standard deviation.

- Expected value and standard deviation.

- Expected value and standard deviation.
- Expected value and standard deviation.
*Bernard Graham* - Expected value and standard deviation.
*Freeman, Jeff* - Expected value and standard deviation.
*Jeff Cole* - Expected value and standard deviation.
*Koster, Raph* - Expected value and standard deviation.
*Katie Lukas* - Expected value and standard deviation.
*Fidelio Gwaihir* - Expected value and standard deviation.
*Katie Lukas*

- Expected value and standard deviation.
- Expected value and standard deviation.
*Matt Mihaly* - Expected value and standard deviation.
*Martin Bassie* - Expected value and standard deviation.
*Katie Lukas* - Expected value and standard deviation.
*Matt Mihaly* - Expected value and standard deviation.
*Paul Schwanz* - Expected value and standard deviation.
*Matt Mihaly*

- Expected value and standard deviation.

- Expected value and standard deviation.

- Expected value and standard deviation.

- Expected value and standard deviation.
- Expected value and standard deviation.
*Koster, Raph* - Expected value and standard deviation.
*Paul Schwanz* - Expected value and standard deviation.
*Amanda Walker* - Expected value and standard deviation.
*John Buehler*

- Expected value and standard deviation.
- Expected value and standard deviation.
*Kwon J. Ekstrom* - Expected value and standard deviation.
*Jeff Cole* - Expected value and standard deviation.
*Paul Schwanz*

- Expected value and standard deviation.
- Expected value and standard deviation.
*Dr. Cat* - Expected value and standard deviation.
*David Loving* - Expected value and standard deviation.
*Pat Ditterline* - Expected value and standard deviation.
*Michael Chui* - Expected value and standard deviation.
*Matt Mihaly*

- Expected value and standard deviation.
- Expected value and standard deviation.
*Kwon J. Ekstrom*

- Expected value and standard deviation.
- Expected value and standard deviation.
*Chanur Silvarian* - Expected value and standard deviation.
*Katie Lukas* - Expected value and standard deviation.
*Daniel.Harman@barclayscapital.com*

- Expected value and standard deviation.
- Expected value and standard deviation.
*Oliver Smith*

- Expected value and standard deviation.

- Expected value and standard deviation.
- Expected value and standard deviation.
*Daniel Anderson* - Expected value and standard deviation.
*Koster, Raph* - Expected value and standard deviation.
*Nicolai Hansen*

- Expected value and standard deviation.

- Expected value and standard deviation.
- Expected value and standard deviation.
*Dark Lamenth* - Expected value and standard deviation.
*Fidelio Gwaihir*

- Expected value and standard deviation.
- Expected value and standard deviation.
*Ola Fosheim GrĂ¸stad* - Expected value and standard deviation.
*gbtmud* - Expected value and standard deviation.
*Tom "cro" Gordon* - Expected value and standard deviation.
*Sheela Caur'Lir* - Expected value and standard deviation.
*Roger Hicks* - Expected value and standard deviation.
*Ola Fosheim GrĂ¸stad*

- Expected value and standard deviation.

- Expected value and standard deviation.

- Expected value and standard deviation.
- Expected value and standard deviation.
*Freeman, Jeff*

- Expected value and standard deviation.

- Expected value and standard deviation.
- Expected value and standard deviation.
*Matt Mihaly* - Expected value and standard deviation.
*Tom "cro" Gordon*

- Expected value and standard deviation.