MU Online Season History, From 2001 to Season 22

MU Online opened in Korea in November 2001 with three classes. Nearly 25 years later it has sixteen, the Korean level cap has gone from the classic era's 400 to 1850, and Season 22 has been live there since September 15, 2026. This MU Online season history puts every version on one timeline, from the pre-season builds players call 97d up to Season 22, and keeps Korean and global dates apart, because the Korean service always gets a season first.

Plenty of season lists get the basics wrong. The Grow Lancer did not arrive in Season 12, the Gun Crusher is not a Season 17 class, and Webzen never released anything called Season 7. Each season on the timeline links to a full article on what it added and what is left of it in Season 22.

MU Online history at a glance

• Seasons: 22 since August 2005, counting eX700 as Season 7, plus the classic versions of 2001 to 2005.
• Classes: 16 today, up from three at the Korean launch. The newest is the Crusader, added in Season 21.
• Level cap: 400 in the classic era; 1800 in Season 22 Part 1-1 and 1850 after the Korean Part 1-2.
• Newest season: Season 22, live in Korea since September 2026. On the global service, Season 21-1 was still the newest in November 2026.
• Release rhythm: from Season 15 to Season 21, each season opened in Korea in September and on the global service the following July.

What are all the MU Online seasons, in order?

Dates are month and year, Korean service first and global service second. Level caps are Korean figures.

Three names on this list are not the ones Webzen printed at the time. Season 7 was released as "MU: eX700", Season 10 was written "Season X" on both services, and the global service called Season 11 "Season XI".

Why do Korean, global and server-file seasons differ?

Three calendars run side by side, and season lists that mix them up disagree:

• The Korean service gets every update first, and since 2010 it has split each season into numbered parts. Korea's "Season 22 Part 1, 1st update" is what players write as Part 1-1.
• The global service gets the same content later and sometimes packages it differently. It released the first two parts of Season X as one update in April 2015, called the Vulcanus update "Season 4.5" when it arrived in 2010, and names its current season "Season 21-1". Webzen's own global update guide still ends at Season 21-1.
• Server files are what private servers run. IGCN's recent releases follow the Korean numbering and arrive a few weeks to two months after Korea, and one release can bundle several Korean parts: IGCN shipped Season 21 as Part 1-1, Part 1-2 and then Part 2-3, so servers jumped straight from 1-2 to 2-3. Labels such as "Season 6 Episode 3", "Season 9.5" or "S16-1" come from file makers and players, not from Webzen.

How did MU Online change from era to era?

2001 to 2005: the classic versions players call 97d

Before seasons, MU was updated by version number. Korea ran a closed test from February 2001 and opened commercially on November 19, 2001 with the Dark Knight, Dark Wizard and Elf; the Magic Gladiator followed three weeks later. The global English service opened on October 13, 2003. Names like 97d and 99b come from those version numbers, and wikis group the whole stretch as Season 0.

Many of MU's longest-lived systems date from here: the Chaos Machine and the first wings in 2002; Devil Square, the 2nd class change, Blood Castle and the 2nd wings in 2003; Chaos Castle, the Dark Lord and Kalima in 2004. Castle Siege followed in March 2005. The 97d and classic-era article explains what each version label actually covers.

2005 to 2011: the classic seasons

Webzen switched to yearly seasons in August 2005. Season 1 added Aida, Crywolf, Kalima 7, the first weapons and armor with a level requirement, and the Fenrir mount. Season 2 opened Kanturu and the Jewel of Harmony, then the 3rd class change in mid-2007. Season 3 brought the Summoner and the Master Level, which let characters keep growing past level 400. Season 4 introduced socket items, Season 5 Gens and +15 items, and Season 6 the Rage Fighter and the official MU Helper.

The global service lagged far behind in this period. It received Season 1's content in 2007, relaunched under Webzen with Season 4 in 2009 and reached Season 6 in 2011. Season 6's final state, after the Fist Master master tree of 2011, is the version players call Season 6 Episode 3: seven classes, sockets and Gens, and no elements yet.

2011 to 2014: elements, Muun and cross-server battles

The update after Season 6 was never called Season 7. Webzen named it MU: eX700 (Korea, November 2011; global, May 2012), and it took the game beyond the MU continent for the first time with Acheron, five elements, Pentagrams with Errtels, the Arca War guild battle and a master level cap of 300. How that element gear works today is explained in our Pentagram and Errtel guide. Season 8 extended Acheron with Debenter, added Jewel of Pandora mining and ended with the first Muun companions. Season 9 added Battle Core cross-server battles, Urk Mountain and Tetra seed spheres.

No class arrived in these years. From the Rage Fighter in October 2010 to the Grow Lancer in August 2014 the roster stayed at seven, so a seven-class server can be running anything from Season 6 to Season 9.

2014 to 2018: Grow Lancer, mastery gear and the 4th class

With Season X came the eighth class, the Grow Lancer, the start of the modern gear ladder with Ruud and the Blood Angel mastery set, and Event Map Square. Each of the next three seasons added a rung. Season 11 brought Dark Angel armor, Season 12 the Holy Angel set and Season 13 Awakening Soul.

Season 12 Part 2 brought the 4th class change at level 800 and the Skill Enhancement Tree, the tier IGCN's server files call Majestic. Season 13 followed with 4th wings, a tier above the 3rd wings that had topped the ladder since 2007, and the first earrings. Over these four seasons the level cap rose from 770 to 1050.

2018 to 2024: a new class almost every year

From Season 14 the Korean service settled into a rhythm: a new season each autumn, usually opening with a new class. First came the Rune Wizard, called the Rune Mage on Webzen's global site, launched alongside a speed server; then the Slayer in Season 15 and the Gun Crusher in Season 16. Season 17 added two classes in one patch, Light Wizard and Lemuria Mage, and Season 18 the Illusion Knight. Season 19 broke the pattern with a 5th class advancement for every class at level 1200, and Season 20 returned with the Alchemist and Temple Guard, MU's first Legendary gear.

From Season 17 on, the same building blocks came back every season: two new endgame hunting grounds, each given an Elite Zone one update later, a new guardian mount (Shining Tail, then Ullr, Leviathan and Tauros), a new pair of mastery earrings, and a level cap raised 50 at a time, from 1350 at the end of Season 16 to 1700 in Season 20. Class renewals became regular too. The Magic Gladiator was rebuilt in Season 16 and the Elf in Season 17; Season 18 reworked four classes around Combat Power, Season 19 reworked the Grow Lancer and Dark Lord, and Season 20 the Rune Wizard.

2025 and 2026: sixteen classes and the renewal seasons

Season 21 completed today's roster with the Crusader, a hammer-wielding holy knight and the 16th class. It also brought a second Legendary tier called Imperial, the Aquila's Temple and Raklion of Oblivion hunting grounds, the Rhino guardian, 9th mastery earrings, a CryWolf renewal and the 1800 level cap, and its Part 2 renewed five existing classes.

Season 22 (Korea, September 2026) adds no class. Its Part 1-1 is a combat update for four classes, the Dark Knight, Rage Fighter, Slayer and knight-type Magic Gladiator, with new attack power types such as Rage for the Dark Knight and Darkness for the Slayer, plus a Hunting Record that separates base and bonus EXP. The Korean Part 1-2 followed in October with the Arcana Archive and level 1850. The same autumn IGCN, a maker of MU server files, announced two client updates: a classic client that it says holds 25 FPS in crowded fights, and a Unity 6 client built for 60+ FPS.

When was each MU Online class added?

The roster in order of arrival: the season and date on the Korean service, then the global date where it is known.

1. Dark Knight: 2001, in the first Korean tests; on the global service from its 2003 launch.
2. Dark Wizard: 2001, alongside the Dark Knight.
3. Elf (Fairy Elf): 2001, added during the Korean beta, before launch.
4. Magic Gladiator: December 2001; under the first rules you needed a level-220 character before you could make one.
5. Dark Lord: August 2004, during the 0.99 builds; its first unlock rule was a level-250 character.
6. Summoner: Season 3, December 2007.
7. Rage Fighter: Season 6, October 2010; global in 2011.
8. Grow Lancer: Season X, August 2014; global April 2015.
9. Rune Wizard (Rune Mage): Season 14, October 2018; global 2019.
10. Slayer: Season 15, September 2019; global July 2020.
11. Gun Crusher: Season 16, September 2020; global July 2021.
12. Light Wizard (White Wizard "Kundun Mephis"): Season 17, September 2021; global July 2022.
13. Lemuria Mage (Mage "Lemuria"): the same Season 17 patch.
14. Illusion Knight: Season 18, September 2022; global July 2023.
15. Alchemist: Season 20, September 2024; global July 2025.
16. Crusader: Season 21, September 2025; global July 2026.

No class arrived between October 2010 and August 2014, and Season 19 gave every existing class a 5th advancement instead of adding one. Seven of the eight Korean autumns from 2018 to 2025 brought a new class, and Season 22 is the first season since Season 19 without one. Our classes by season guide turns this order into a quick server check.

Which MU Online season should you play?

No season is objectively best. Each era changes how long it takes to feel strong, how many systems you juggle and which classes exist, so start from what you want out of MU:

• The original feel. A 97d or 0.99-era server: four or five classes, Devil Square and Blood Castle, two wing tiers and no Master Level. The label is used loosely, so ask which version's content a "97d" server really follows.
• Classic, with comforts. Season 6 Episode 3 keeps seven classes, the Master Level, sockets, Gens and +15 items plus the official MU Helper, without the element system eX700 added. Of all classic versions it has the broadest support: open-source server and client projects target it, and the only classic package IGCN offers is this one.
• A mid-era version. Server files for Season 16, Season 13, Season 12 Episode 2, Season 9 and its "9.5" variant, and Season 8 have circulated for years, so those labels still turn up on private servers. Each version stops at its own season's class roster.
• Every class and the deepest endgame. Season 21 Part 2-3 or Season 22: all sixteen classes, the 5th class advancement, Legendary gear, guardian mounts up to the Rhino and level 1800. Season 22 adds the newest balance pass for four classes, and it is the season SilverMU runs.
• One class in particular. Check its arrival above. A Crusader needs Season 21 or later, an Alchemist Season 20, an Illusion Knight Season 18, and the Light Wizard or Lemuria Mage Season 17.

More content is not automatically better: newer seasons mean more systems to learn and more power to chase. Our server selection checklist treats the season as one factor among nine, and the best class guide helps once you have picked.

How can you tell which season a server runs?

A website banner is easy to change. The game client is not, and four checks settle the question:

1. Count the classes on the character creation screen. Four point to a 97d-era build, five to the 0.99 era through Season 2, six to Seasons 3 to 5, seven to Seasons 6 to 9 and eight to Seasons X to 13. Nine, ten and eleven mean Seasons 14, 15 and 16, thirteen means Season 17, fourteen Season 18 or 19, fifteen Season 20, and sixteen Season 21 or 22.
2. Separate Season 21 from Season 22. Both have sixteen classes. In Season 22 Part 1-1 the Dark Knight's master tree swaps its Death Stab entries for Fire Blow ones, Fire Blow itself becomes a regular skill, and the Hunting Record shows Base EXP and Bonus EXP on separate lines.
3. Ask for the part number. Within Season 21, Part 1-2 stops at level 1750 with Aquila's Temple as its newest map, while Part 2-3 brings Raklion of Oblivion, the Rhino and the 1800 cap. For Season 22, IGCN's files are Part 1-1 as of November 2026, which means level 1800 and no Arcana Archive.
4. Compare with the current status. Our current season guide tracks the newest official and server-file releases.

MU Online season history FAQ

How many seasons does MU Online have?

Twenty-two as of November 2026, counting eX700 as Season 7, plus the classic versions released in Korea from 2001 to 2005, which wikis call Season 0. Season 22 is the newest.

What is the newest MU Online season?

Season 22. The Korean service launched it on September 15, 2026, and its second update, Part 1-2, arrived on October 13. Webzen's global service has not started Season 22 yet, and IGCN's newest server files, the kind private servers run, are Season 22 Part 1-1, announced on October 6, 2026.

When was MU Online released?

The Korean service opened commercially on November 19, 2001, after a closed test that began in February 2001. The global English service opened on October 13, 2003.

What is the max level in MU Online?

It depends on the version. Korea's cap has been 1850 since Season 22 Part 1-2. In IGCN's server files for Season 22 Part 1-1 the cap is 1800 (level 400 plus Master Level 1400), and the global service was at 1750 as of November 2026.

Is there a MU Online Season 23?

Not yet. As of November 3, 2026, Webzen has not announced a Season 23 for either service, and Korea has not announced a Season 22 Part 1-3 either.

Start your own MU history on SilverMU

Almost every era above still lives in Season 22. IGCN's Season 22 server files still include Devil Square, Blood Castle and Chaos Castle from 2003 and 2004, Kalima, Castle Siege, Crywolf and Kanturu, Acheron's maps from eX700, and the hunting grounds of every later season up to Raklion of Oblivion.

SilverMU runs the 22.1.1.0 build of Season 22 Part 1-1 with all sixteen classes, and it is still being tested. You can register a free account today. When the client is published you will find it on the download page. It already carries IGCN's 25 FPS update for the classic client, and a move to the 60+ FPS high-performance client is coming later; the news will announce it. The event schedule, final rates and other settings also appear in the news before launch, and the event and ranking pages fill in once the server is online.