O2Jam wiki
Developer O2Media
Publishers Flag of South Korea MOMO Corp. Inc (previously O2Media, Inc. -> Nowcom)
Platform Microsoft Windows
System requirements 430MB hard disk space (excluding song downloads)
350 MHz CPU or higher
DirectX 8.0 or higher
Internet access
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O2Jam (Korean: 오투잼) is a casual rhythm-matching online game developed in South Korea by O2Media. At present there are agencies in many countries and regions.


Playing the game is divided between finding a room to play in, selecting a song, and playing a song. There are Music Halls, technically servers, on which a user can play in. Some music halls are named after the muses in Greek mythology.

  • There are 3 servers in the Korean version: Melpomin (Melpomin), Kalliope and Kleo (Clio).
  • In the Philippine version, there are six servers, all of which are free to play. These are Euta, Thalo, Kalliope, Melpomin, Kleo and Philix. Euta, Kalliope, and Kleo are the most populous servers.
  • In the Malaysian version of O2Jam, there are also three servers: Kalliope, Kleo and Thalia. All three are free to use, although about half of the songs cost money to play. Each server works under song level restrictions: Kalliope (1-13), Thalia (7-19) and Kleo (13+).
Main article: Room

After choosing a server on which to play, the player (commonly called an O2Jammer in the O2Jam community) is presented with a list of "channels," each of which allows a maximum of 100 users at a time. Upon selecting a channel, the player is presented with a list of rooms. The types of rooms on O2Jam are Single rooms, VS rooms, Album rooms, Couple rooms, and Jam rooms (not implemented).

Selecting a song[]

Over 350 songs on the Filipino server and 270 on the Malaysian server are currently available to play Including all O2Jam versions, there are over 580 songs available for playing(~3.4GB in .ojn and .ojm files; over 1300 songs if you count unofficial ones, 6.9GB). While some of them come included with the game's full installer, many of them require a separate download and e-points after installation. Unfortunately, the downloads of the songs are very slow, sometimes reaching 15 minutes on a cable modem. To fix this, all of the songs are available through a Bittorrent download.

The genres that the songs are part of run the gamut from piano pieces to techno versions of classical pieces to songs that are reminiscent of J-Pop, with an unusually large number of Christmas -themed songs. Most of the songs have 3 difficulty levels of play. The harder the difficulty, the more notes, drum beats, and other sounds need to be played by the player, as opposed to automatically being played in the background. On the hardest difficulty, many songs have a limited amount of music not being played by the user.

To be able to play a song in a VS Room, the song must either be free and each player have the song downloaded, or be paid for and downloaded by each player. To play in an Album Room, all songs in the album being played must have been downloaded before the album can be played.

A small optional step while selecting the song is selecting the background that all of the players will play on. This is mostly a cosmetic change, since all this does is determine what playing field the avatars will be standing on and what font the combo counter and note quality indicator (Cool/Good/etc.) will be in, as well as determining the visual effect that displays whenever a note is hit well. By default, the background is random.

Playing a song[]

PillChat boxComboJam counterHi-speedDuration of the songDuration of the songNote guideline lengthTitle of the songVolumeEqualizerMax comboSkill ringsNote hit judgmentExit buttonLevelIGNLevelIGNAvatarO2MO BalloonHuskyHealthHealthOhmTarget barHealthScoreGood
About this image

O2Jammers playing Rhyme Without Reason by Hilera. (This is an image map.)

See this page for a full-sized version of the image map on the right.

Horizontal bars slide down a series of seven columns, each corresponding to a key on the keyboard. Just before the notes hit the bottom of the column, the player has to hit the key corresponding to that column. Each keypress emits a note, vocal, or other instrument that creates a full-sounding song. A correct hit is also rewarded with a small 3D visual effect that is determined by the background on which the players are playing.

The grading scale used by the game is, from most accurate press to least, Cool, Good, Bad, and Miss. Consecutive Cool and Good notes add both to the player's combo and to their Jam meter. When the Jam meter fills up (if you get 25 Cools, 50 Goods, or a combination all in one streak), a large number flashes in front of the player's avatar indicating their current Jam Combo. The goal of the player is to get both a high individual note combo as well as a high Jam Combo. Because the Jam meter fills up faster when a player hits a Cool instead of a Good, two players can both get a full combo (hitting every note as a Cool or Good) but still have a different Jam Combo.

When the player gets fifteen Cools in a row, a blue pill appears in the pill meter, with a maximum of five pills. Each one of these pills will transform a Bad hit into a Cool, keeping the player's combo going.

After all of the players are done playing the song, their individual scores are ranked against each other, and all players are awarded Gems based on how well they performed.

One way players challenge themselves is by increasing or decreasing the speed at which the notes descend. The multipliers from the "base speed" are x0.5, x1, x1.5, x2, x2.5, x3, x4, x5, x6, and x8. These modifiers are often points of contention in VS Rooms, as many players try to play a song at the fastest speed possible, while others prefer to have the notes a bit slower. With many harder songs, x1 is used to increase the challenge, as the notes end up closer together, making it harder to read. Speeding up the notes does not affect the music at all, but instead spreads out the notes, making them (in non-extreme cases) easier to read in relation to each other, though the notes appear on screen for less time.

As of January 27, 2006, the x8 speed has been replaced by the xR speed in the Malaysian version of O2Jam. This mode allocates a different speed to each note column when playing the song, making songs even more challenging, and difficult to memorize.


An O2Jam player can level up from level 0 up to level 100. Upon reaching level 100, the player's experience (EXP) continues to increase, but the level stays at 100. An O2Jam Gamemaster|GM has a level of 999.


Main article: List of missions in O2Jam

Every four levels, starting with level 4, a mission will be assigned to the O2Jam player. Unless a player completes the mission, the player's EXP and level will not increase.


O2Jam has two methods of paying for items in game, one of which involves real-life money (e-Points) and the other of which is rewarded through playing the game (Gems).

  • e-Points are the universal currency on the Malaysian O2Jam's host website, e-Games. The price is approximately $6.00 (USD) for 200 e-Points, with discounts when buying in bulk. Songs and avatar items can be purchased with e-Points, with the cost rarely going over 50 e-Points per song/item. The highest song cost is 50 e-points and the lowest is 10 e-points. In the Philippine version, 1 e-Point is roughly equivalent to PhP1.00
  • MCASH is the Chinese equivalent of e-Points.
  • Gems are awarded to players who play in either single rooms up to level 10 or in multiplayer rooms (VS or Album rooms). The better a player does on a song (the higher number of Cool and Good notes, max combo and Jam Combo) and the more difficult the song, the more Gems they receive.

As of September 9, 2006, bonuses have been added to the Gems on certain Malaysian servers. Thalia gives +10% and Kleo now gives +20% to the Gem count per song. About half of the avatar items, and a small number of the pay-to-play songs are purchasable using this in-game currency. The highest song cost is 60,000 Gems and the lowest is 4,000 Gems.

Pay to play/free[]

The Korean O2Jam comes in both free and pay to play versions.

The pay to play version allows players a few extra options:

  • Avatars: Each player is represented with an avatar that they may customize with a wide variety of clothing, musical instruments, and other various accouterments. Paying members are allowed to buy additional avatar items with E-points (abbreviated to EP in-game), such as Skill Rings, which allow for challenging variations in usual game play (see below).
  • More Songs: Most of the new songs that are released for the game are only for the pay-to-play members. The vast majority of the songs are purchased with E-points, while a few of them are purchased with Gems. Buying a song only unlocks the user account's ability to play it.

Downloading the song files is separate from purchasing it, so many O2Jam players have the files for songs which that they cannot play.

  • Levelling Up: While on the Free server, players are able to gain EXP and therefore level up. The amount of EXP (experience) gained by players varies from song to song, depending on its difficulty and performance. The harder the song and the higher the score, the more EXP the player gains. As of September 9, 2006, bonuses have been added to the EXP given on certain servers. Thalia gives +5% and Kleo now gives +10% more EXP per song.

As of December 1, 2005, the Malaysian version of O2Jam has become free for all players. However, users are required to pay to play for about half of the songs if they wish to play them. Gaining EXP, buying avatar items and playing all of the free songs (of which there are currently 167, inclusive of 12 songs payable with gems) are freely available to all users. As of October 25, 2007, there are 149 pay-to-play songs on O2Jam Malaysia, which results in a total of 316 songs (excluding previous removals) on that server.

Song list[]

Main article: List of songs in O2Jam

Skill rings[]

Main article: Skill ring

Skill rings allow for variations of the usual game play in different ways. Skill Rings must be activated by the room host and apply to all players in that room during the song period. There are three classifications of skill rings: Arrange, Visibility and Power.

  • Power Ring: Grant everyone who enters the room the access to all paid songs
  • Arrange: Consists of Mirror, Panic and Random. Changes the arrangement of the notes.
  • Visibility: Consists of Hidden, Sudden and Dark. Covers specific part of the note panel for extra difficulty.

IN-game Events[]

see main article Events(O2jam Malaysia)


Timing window[]

Some players have criticized the timing window for each note judgment, which is based not on milliseconds, but rather beats; this is especially noticeable in the beginning of the song zl, in which the song slows down to 1 BPM and the player has four notes to hit. A note could be somewhat above the red bar on the screen and still be registered as a Cool when hit.


Players may experience repetitive strain injury upon playing the game over an extended period of time (especially when playing songs with high levels) just like how a piano player might get strained from playing the piano. This is because of repetitive presses on the keyboard on the same keys throughout the game.


Some players are using Jambots and cheating devices to cheat on O2Jam to get themselves into the rankings or high scores, unlimited gold and e-Points.

MYO2, one of the most well known hack made by IT Song, which grant the user unlimited skill rings, access to all songs, ability to kick the room master, unlimited pills, fixed difficulty, god mode and auto-play function. This has terrorized servers like Malaysian O2Jam, causing the company to lose money and damaging the players community.


Simulations are possible with third party programs, of which O2Jam relatively easy to be played by.

Known methods:

  • Private servers
  • Emulators (O2Emu, O2Solo, O2Mania, Open2Jam, etc)


A service which has never been implemented in any servers, but players have created their own guild / clan / team to compete against others.

See also[]

External links[]

Official sites[]