Battle.net

Battle.net is an online gaming service provided by Blizzard Entertainment responsible for hosting StarCraft multiplayer games and related services. It was launched in January of 1997 with the release of Blizzard's action-RPG &mdash; Diablo (computer game)Diablo. Battle.net was the first online gaming service incorporated directly into the games that make use of it, in contrast to the external interfaces used by the other online services at the time. This feature, along with ease of account creations and the absence of member fees, caused Battle.net to become popular among gamers and became a major selling point for Diablo and subsequent Blizzard games.

Since the successful launch of Battle.net many companies have published online game services mimicking Blizzard's service package and the user interface.

Diablo
When the service initially launched with Diablo, Battle.net offered only a few basic services like chatting and game listings. Players could connect to the service, talk with other gamers and join multiplayer games of Diablo. Besides user account data, no game data was stored on the Battle.net servers. When a player connected to a game, they would be connecting directly to the other players in the game. No data was sent through the Battle.net servers. While this made the service quick and easy to use, it quickly led to rampant cheating since players using cheats could modify their game data locally. However, since there was an option to create private games, many players ended up playing with people whom they knew.

StarCraft
With the release of their next game StarCraft in 1998, usage of the Battle.net service increased significantly. With this game, features such as ladder ranking and game filters were added to the service. Battle.net grew even larger after the release of the expansion pack StarCraft: Brood War. Concurrent player counts and games played reached the tens of thousands. This was especially evident in South Korea where StarCraft became a runaway hit and concurrent player counts on Battle.net would often be many times what they were in the United States.

StarCraft also brought with it a new copyright protection scheme using CD keys. Under Diablo, Battle.net would allow anyone who had a copy of the game to connect to the service. This allowed people who pirated the game to play on Battle.net. With StarCraft, only those players who had a valid CD key were allowed onto the service. A StarCraft CD key is a generated 13-digit number that could either be muted (unable to chat), voided (restricted to channel 'The Void'), banned (disabled usage), or usually working (no restrictions). In addition, only one person can be connected to Battle.net service using a specific CD key at a time. Every Blizzard game since StarCraft has required a unique, valid CD key to connect to Battle.net (excluding Starcraft: Brood War, Starcraft's expansion which was also released in 1998). With the release of the Gateway system in Broodwar, two players can play at the same time, as long as they are on different gateways, though they cannot play in the same game, chat with each other, etc.

Warcraft II: Battle.net Edition
The next year, seeing the popularity of StarCraft on Battle.net, Blizzard decided to re-release their previous RTS game Warcraft II: Tides of Darkness packaged with its expansion pack Warcraft II: Beyond the Dark Portal in a version that could be played over Battle.net. This version was titled Warcraft II: Battle.net Edition. Previously, Warcraft II could only be played over the Internet using the IPX network emulator Kali or the now defunct online service Engage. The new version also included support for ladders and a host of other non-Battle.net related features.

Diablo II
The new millennium brought a new game and a new era for Battle.net. Diablo II was released in 2000 to much fan-fare. The main highlight of Diablo II as it relates to Battle.net was that the game was completely client-server based. The game was no longer simulated on each player's computer, but instead was run on Blizzard's server. This also meant that all of the character data for the game was stored on the Battle.net servers. This effectively put an end to cheating as it had been known during the period of the original Diablo. The game also had an open character feature on Battle.net which stored the player's character on the client. This allowed players to play characters locally or on a LAN, and then use those same characters on Battle.net. However, any open games played on Battle.net were not protected from cheating by other players since they could have modified their characters locally. Diablo II also had a unique feature that would show the players in the Battle.net chatroom as avatars who looked like their characters did in the game. It also used a different Battle.net interface than previous games, where previously there were mainly only color differences. There was also expanded ladder support including a "Hardcore" ladder which listed players whose characters would be removed permanently if they died in-game. Again, with Diablo II usage of Battle.net increased steadily, climbing even higher with the release of the expansion pack Diablo II: Lord of Destruction in 2001.

Warcraft III
Warcraft III: Reign of Chaos was released in 2002 and combined with its expansion pack Warcraft III: The Frozen Throne which was released in 2003 are the most recent games Blizzard released which support Battle.net. The release of these two games brought with them a number of new features to the online service. The most significant feature to be added was probably the concept of Anonymous Matchmaking or commonly referred to by Warcraft players as AMM. This feature allowed a user who wanted to play a game to simply press a button and automatically be matched up with one or more other players who were similar in skill (based on ranking) and also wanted to play a game. This allowed for people to get into games quickly and easily. It also reduced win-trading, where two people would purposely win and lose games to artificially raise their rank on the ladder. The matchmaking concept was also expanded to team games in a feature called "Arranged Teams". In an arranged team game, you could get together with a friend of yours to make a team, which was then anonymously matched up with another team of the same size and rank. Automated tournaments were added in the expansion, where players would compete to be crowned tournament champion in a series of games played throughout the day. In addition to the new game styles, a slew of other features were added including selectable chatroom icons unlocked based on the player's number of wins, a friends list, and clan support.

Growth history
Blizzard claims "millions of active users" on Battle.net, and that they are the leaders of online gaming, noting that even Xbox Live doesn't even come close. By November 1997 they had 22 million games played, 1.25 million different users, and that they averaged 3,500 new users each day. By April 1999, it was reported that Battle.net had 2.3 million active users, and more than 50,000 concurrent users. By September 2002, their active user count had jumped to 11 million. By September 2004, their active user count was up to nearly 12 million, spending more than 2.1 million hours online each day, and they had an average of 200,000 concurrent users, with a peak concurrent user count of 400,000.

Community
A community of developers has arisen around Battle.net. Many unofficial clients are available for Battle.net, and most of the protocol used by Battle.net-enabled games has been reverse-engineered and published by volunteers.

Also, several communication tools have been made, like a "whisper" tool, so that you could talk to your friends even if they were in a game

Custom games (using maps that were not made by Blizzard) have helped build the community, and now are a substantial portion of the games played among the most popular of these games in WarCraft 3 (Blizzard's most recent Battle.net game) are tower defense maps and Hero solo maps (like DOTA, and arena maps).

Gem
Diablo II: Lord of Destruction's Battle.net room has a small blue "gem" in it, on the middle of the screen, above the players list. When you click the gem, a message comes up on the screen in purple, which reads "Gem Activated." Clicking again yields "Gem Deactivated." Sometimes, "secret" messages appear, such as "Perfect Gem Activated", or "Mooooooooo!" (the second message was removed in later patches).

Battle.net has stated that the gem is "working as intended and exceeding expectations." Although rumors persist, the gem appears to do nothing. This is supported by many trials by many people, the fact that when the gem is clicked, there is, in fact, no data sent to Battle.net, and a statement by Blizzard saying "sometimes a gem is simply a gem." Whether this was the original intent or its purpose was for an abandoned functionality of the game, or it really does have a purpose that remains undiscovered, the gem continues to amuse and perplex many Diablo II players.

In the Warcraft III World Editor, the Gem makes a cameo. When activated, it turns on or off the Death effects for creatures which are deleted from the editor.