Internet Chess Servers (ICSes)

ICS: n. 1: an acronym for Internet Chess Server  2: the original chess server [syn. {ICC}]  3: an UNIX server that provides telnet access to ASCII resources via the Internet  4: term used to label any kind of Internet resource that allows humans to play chess online with other humans (incorrectly)  5: a command-line prompt  [plural - ICSes]


   In general, the definition of an ICS is a chess server that you can telnet to. Any sort of server that only allows HTML, JAVA or proprietary interface access is not an ICS. When people refer to an ICS they are referring to a specific subset of capabilities. All of those capabilities entail the ability to login via telnet.

The functions of an ICS are multifold. Think of it as being a very powerful interface for connecting chess players from all over the globe together on one server to chat and play chess games as well as playing related variants of chess supported on that particular ICS. A commonly supported variant on an ICS is bughouse.

Getting onto an ICS

One way that will always work is telnetting into the server. Some people do not know what telnet means or what it is, so I will define telnet for them and explain how to work with it.

Telnet is a protocol that allows you to connect to other computers (also known as hosts) on a TCP/IP network (such as the Internet). You use software on your own computer known as a 'telnet client' to make a connection to another computer. The other computer (the remote host) has a telnet server which your telnet client will communicate with to establish a connection. Once you have connected to the remote host, your telnet client becomes a virtual terminal. Most of the time after establishing a connection, you will be queried for your username and password on the remote system. This is known as logging on. For most ICSes, their ASCII login screen will provide you with information on how to log in to the server. They may provide links or instructions about how to log on as a guest.

Telnet clients are available for all major operating systems.  

Command line telnet clients are provided with most versions of Mac OS X, Windows 95 and up, UNIX and Linux. To use them, go to their command lines (shell or DOS prompt) then enter:

telnet remote host

Replace 'remote host' with the name of the remote computer you wish to connect to.

Using an Interface

You do have to telnet to get onto an ICS. However, what most people have done is ever since the ICS was released several years ago has been to produce several different chess interfaces. What those chess interfaces do are that they are basically GUI's (graphical user interfaces) that simplify the tasks of telnetting for the user. It also allows the user to play with a nice GUI for the chess board. This basically means that the GUI will translate the strings of characters that the server outputs to your client and display it on the GUI. Before chess interfaces came about, the only option was to play by typing your moves and with an ASCII board (note: ASCII is a text character set).

    8  | *R| *N| *B| *Q| *K| *B| *N| *R|     Move # : 1 (White)
    7  | *P| *P| *P| *P| *P| *P| *P| *P|
    6  |   |   |   |   |   |   |   |   |
    5  |   |   |   |   |   |   |   |   |     Black Clock : 0:00.000
    4  |   |   |   |   |   |   |   |   |     White Clock : 0:00.000
    3  |   |   |   |   |   |   |   |   |     Black Strength : 39
    2  | P | P | P | P | P | P | P | P |     White Strength : 39
    1  | R | N | B | Q | K | B | N | R |
         a   b   c   d   e   f   g   h
This is known as 'style 1' on most ICSes. You would play by typing your moves. The difference here is that the black pieces had asterisks before their letters. Several styles exist on ICSes but this one was the most popular of the ASCII boards, or at least the default setting.

With the advent of the chess interface, the default style became 12. Style 12 is basically a raw dump of data from the server, which is sent to the telnetted user. The chess interface will read the information and translate it (prettify it) on the graphical chessboard for the user.

Another notable style is style 9 which is the style that blindfolded players use (cannot see the board, only the last 2 moves made). This is primarily used by players as a training device or for entertainment.

Finding an Interface

   There are several interfaces available out there.  Several are available through the ICS downloads pages themselves.  Others can be located via searching the Internet.  But tougher to do without spending some time finding, installing, and using various interfaces is finding an interface that meets your needs.  All those programs have different looks, feels, and features.  Finding the right mix of those that appeals to you is a matter of personal preference in most cases.

You can find reviews and downloads of some chess interfaces on my Interfaces page.

Creation of the first ICS

   In the late 1980's and early 1990's a band of volunteers worked together to create the FIRST ever "ICS" for fun. Players logged on via telnet and the board was displayed as ASCII text. Bugs were rampant in the server code as ever is in any piece of complex software ever written. For example, one could capture rooks en passant. Over time, this small community of players and coders alike worked together to improve the software of the server itself while reaping the benefits of this close-knit community. More features were added to the server, such as ELO ratings. No timeseal existed in those days and people would play time controls such as 10 12 with their ASCII boards, typing in their moves as previously stated.

You can find further reading on the creation of the first ICS elsewhere on the Internet, but a primary source would be Chris Petroff's USENET archiveTim Mann's ICS page also has a short summary and some links from the past to the various ICS servers that have existed at points in time.

Timeseal / Timestamp / Timelock / Accuclock

   Those terms refer to a system originally set up by Henrik Gram (Hawk) to compensate for the time lost by players during transmission time of moves between client to server to client. Originally, latency and lag of the players was compensated for by players by playing with increments. Lagflagging was an abhorrent gesture of the time, flagging a player when he was lagging out. I will write more about this topic at a later date.

Current ICS Servers (As of March 2009)

Past ICS Servers (As of March 2009)

Non-ICS Places to Play

   For whatever reason you might have for choosing not to play at an ICS such as preferring correspondence chess over live chess, there are a few other sites available for playing chess that aren't ICSes:

[Last Modified : 24 February 2009 -- Nick Long]
2009 Nick Long