Season 0 to Season 9

These start dates come from the Korean version timeline shown on Wikipedia. Global players received each update later, so the Global dates in the sections below are different. The full list up to Season 22 is on the Timeline page.

Season 0 covers the original game, from the 2001 launch until August 2005. The saved sources say little about the content of Seasons 1 to 6, but a few milestones are clear: the Summoner class arrived in Season 3, and Season 6 brought new quests for beginners (see Beginner Quests).

For the Global version, Season 4 was a fresh start: on 21 May 2009 Webzen opened a new Season 4 realm on its own portal as a free-to-play game, after a beta in April. Unlike that beta, characters were no longer wiped.

Global players got the eX700 expansion on 31 May 2012, which Webzen called one of the largest updates in the game's history:

• Master Levels went up from 200 to 300, so existing master skills were reset (see Master Skill Tree).
• The new map Acheron and the guild war system Arca War.
• The Elemental System with five elements (Water, Fire, Wind, Earth and Darkness) that affects both PvP and PvE.
• A new server, Yggdrasil.

eX700 Plus followed on 10 October 2012. It raised the level cap from 700 to 702, added socketed weapons and item sets for each race, brought four 'Evil's Cursed Wing' Wings, and redesigned the interface with HP bars for monsters and party members.

Season 9 reached Global servers on 11 November 2014. It opened Urk Mountain, a new hunting ground in Acheron whose boss Lord Silvester drops a pentagram, a socket item, a sphere or a tetra crystal. It also added the level 4 Seed Sphere (Tetra), which drops from monsters of level 132 and up or is made from a Seed and a Sphere at the Seed Master NPC (see Socket System & Seed Spheres). The Muun system got mount-type Muuns, an auto-active skill and a sub-slot, and a wide-screen mode arrived along with class and stat balance changes.

On 3 February 2015 came Battle Core, a separate server where characters from different servers meet to find the strongest. Players sign up through the NPC Ellin, then enter the Chaos Castle and Tormented Square Survival of the Fittest events through the NPC Mite.