In 2004, the official Lineage II server software was leaked and a significant number of private servers appeared. Modification of the official game client allowed players to connect to non-official (private) servers. However, some private servers that run emulated server code require only modification of the hosts file in the player's operating system, leaving the client unchanged.
There are currently three completely independent open source server emulators. All of which have been released under the GPL license and allow the client to connect with only a host file change. L2J, the first emulator created for Lineage II, is written in Java, and is the most mature server emulator available. L2Adena is written in C++ and is currently under development. L2castell is a complete rewrite of a Java server emulator started by L2J developers who disagreed with certain design aspects of the server.
Some private servers have populations reaching into the thousands. Playing on private servers is free, although many are supported by donations from players.
After the initial Prelude and Chronicle 1 file leaks, the official software was modified by the use of Assembly Language, Hexadecimal Editing and DLL hooks to support the clients and features of later Chronicles. These modified versions of the Chronicle 1 software were called "Hybrid".
Currently, it is common for private servers to be found hosting the Kamael version of the client. The game play is commonly altered by boosting the experience rates, the monetary drop rate, and the item drop rate, making higher-quality gear easier to obtain. Many servers also feature unique "twists" which keep them apart from the rest.
In 2006, the Lineage II Chronicle 4 Public Test Server files were leaked and sold to private server owners. Figures as high as $15,000 US were being asked, but it's not confirmed if anyone paid for this, as the files were later leaked from the sellers and made publicly available. The C4 applications require a 64-bit microprocessor architecture to run.
NCsoft has taken some actions against private servers. One such server has been shut down by the FBI while its owner has been arrested for copyright violation.
As of 2007, the community created server files for Chronicle 5 have reached a useful level of accuracy. Private servers based on these files are getting more and more popular in the private server community.
The GameSites200 Lineage II Section, Hopzone and Games Top 100 are the main places of competition, where each server competes for user votes to rank itself among the top servers. Currently these sites contain very inaccurate vote results, as there is an ongoing epidemic of "proxy voting" (cheating).
NCsoft Involvement
On November 16, 2006, the private server L2Extreme was shut down by the FBI. L2Extreme has recently resurfaced in the private gaming community. During the time L2Extreme was shut down, countless rumors pertaining to the reasons surfaced.
On November 20, 2006, NCsoft issued an official press release on their involvement with the FBI raid, verifying its validity. Additionally, the news was posted on the official Lineage II website, and a report was also posted on the FBI website in February 2007.
On November 21, 2006, NCsoft began sending out cease and desist warnings to many private servers or their hosts.[citation needed]