MU Online Master Skill Tree Guide – All Classes (Season 20 & 21)

This guide explains how the Master Level and Master Skill Tree systems work in MU Online for all classes, from classic characters like Dark Knight and Dark Wizard to modern Season 21 classes like Rune Mage, Slayer, Gun Crusher, White Wizard, Lemuria Mage, Illusion Knight, Alchemist and Crusader.

You will learn:

  • How Master Level works and how to gain Master EXP.
  • How the 3 Master Skill Tree categories work for every class.
  • Basic build ideas for melee, ranged, mage and support characters.
  • How to reset your Master Skill Tree with Scrolls of Oblivion.
What is Master Level? How to Gain Master EXP Master Skill Tree Structure Category 1 – Defense & Utility Category 2 – Attack Category 3 – Class Skills Build Tips for Each Class Type How to Reset Master Skill Tree
Important: Exact values (max Master Level, required monster level, skill names) can be customized on each server. This guide is based on official Webzen EX700+ / Season 20 style files and works very well for modern Season 20 & Season 21 servers, including MUOnline.ai.

What is Master Level & Master Skill Tree?

After your character reaches level 400 and completes the 3rd class quest (Apostle Devin in Crywolf), you unlock the Master Level system. From this point:

  • Your normal level stays at 400 and you start gaining Master Levels (ML).
  • Every Master Level gives:
    • +1 Master Skill Point (used in the Master Skill Tree).
    • A small increase to your HP, Mana and SD.
  • You also unlock the Master Skill Tree window (usually via the “A” key or the skill tree icon in the UI).

The Master Skill Tree is a large set of passive bonuses and skill upgrades that turn your character into a real late‑game monster – more damage, more defense, more speed and special upgrades for your favorite skills.

How to Gain Master EXP

Monsters that give Master EXP

To gain Master EXP, you must kill monsters that are high enough level. On most Season 20/21 configurations:

  • You need to kill monsters around level 95+ to gain Master EXP.
  • In practice this means maps like Karutan and above, plus all high‑end events.

Events that give Master EXP

High‑tier instances are designed for Master Level characters and give very good Master EXP:

Event Level Range Master EXP? Notes
Blood Castle 8 Master Level 0–200 Yes Top XP, great for early Master Levels.
Devil Square 7 Master Level 0–200 Yes Very dense mobs, good EXP & jewels.
Chaos Castle 7 Master Level 0–200 Yes Risky (knock‑backs) but fast experience.
Illusion Temple 6 Master Level 0–200 Yes Mixed PvP/PvM, strong exp & rewards.

Many private servers also add Master EXP bonuses to newer maps such as Deep Dungeon, Swamp of Calmness, Ferea, Nixies Lake, Tormenta, Aquilas Temple and others. Always check your server’s rates and recommended Master Level leveling spots.

Experience & Zen loss on death

When a Master Level character dies, you can lose some Master EXP and Zen. A common configuration for Master Level 0–200 is:

PK Status Master EXP Lost Zen Lost
Normal ≈ 0.7% of current Master EXP ≈ 4% of carried Zen
PK Level 1 ≈ 2% ≈ 4%
PK Level 2 ≈ 3% ≈ 4%
Murderer (red) ≈ 4% ≈ 4%
Tip: When you are close to a Master Level up, avoid dangerous PK zones. Losing 3–4% Master EXP at high levels hurts a lot more than at ML 0–10.

Master Skill Tree Structure – 3 Categories, All Classes

The Master Skill Tree is shared by all 3rd‑class or higher characters. It is divided into three categories (or “tabs”), each with rows called ranks. Each skill:

  • Can usually hold up to 20 points (20 “grades”).
  • Requires you to put some points in skills above it to unlock the path below.
  • Gives more power with each point – damage, defense, speed, etc.

The names of the categories depend on your class and client language, but on modern Season 20–21 files they usually follow this logic:

Category Common Names What it Focuses On
Category 1 Protection, Peace, Blessing, Guardian, Solidity, Determination, Willpower Defense, HP, SD, auto recovery, resistances, durability reduction.
Category 2 Bravery, Wisdom, Salvation, Chaos, Fighting Spirit, Justice, Determination Raw damage: Attack/Wizardry, crit & excellent chance, attack rate, weapon masteries.
Category 3 Anger, Overcome, Storm, Honor, Ultimatum, Conquer, Destruction Class‑specific skills: Strengthener & Mastery for your main attacks.
How many points can I spend?
On many EX700+/Season 20 setups the default cap is around Master Level 200 (200 points), but some servers extend this to 400, 600 or more. MUOnline.ai and most Season 21 servers use a raised cap so you can eventually fill most of the important skills.

Category 1 – Defense & Utility (All Classes)

Category 1 is your defense and survivability tree. It has the same structure for every 3rd‑class character. Early ranks usually include:

  • Durability Reduction (1/2/3) – slows down the rate your weapons, armor, rings, pendants and pets lose durability.
  • PvP Defense Rate Increase – makes enemies miss more often in PvP.
  • Maximum SD Increase – bigger SD “shield” before HP is hit.
  • Automatic HP / Mana / AG Recovery – faster auto regen while hunting.
  • SD Recovery Speed – helps SD bounce back after hits.
  • Poison / Lightning / Ice Resistance – reduces damage from those elements or chance of debuffs.
  • Defense Increase & Defense Success Rate Increase – more defense and more “MISS” against monsters.
Recommendation: For almost every build, put at least a few points into Maximum SD, Defense Increase and Auto HP/Mana Recovery. These make leveling safer and reduce potion costs.

Category 2 – Attack & Weapon Mastery

Category 2 is your main damage tree. Names differ (Valor, Bravery, Wisdom, Justice, Fighting Spirit...), but the idea is always the same: boost your normal hits and generic skill damage.

Typical bonuses in Category 2:

  • Attack / Wizardry / Curse Increase – more base damage.
  • Attack Success Rate Increase – reduces “MISS”, especially vs high‑level monsters.
  • Critical Damage Rate & Excellent Damage Rate – more crits and exc damage hits.
  • Double Damage Chance (on some servers) – chance to double your damage.
  • Attack Speed Increase – faster hits and faster spam of main skills.
  • Weapon Strengtheners & Masteries – bonuses for swords, staves, bows, crossbows, maces, spears, guns, etc.

For pure damage builds (PvE or PvP) this is usually the first category you max out after taking a few survival skills from Category 1.

Category 3 – Class‑Specific Skill Enhancements

Category 3 is where each class becomes unique. This tree is made of Strengthener and Mastery skills for your main attacks and buffs.

Examples by class

  • Blade Master / Dragon Knight / Ignition Knight – Strengtheners & Masteries for skills like Twisting Slash, Death Stab, Rageful Blow, Sword Slash, Blood Storm, etc.
  • Grand Master / Soul Wizard / Darkness Wizard – upgrades for Poison, Flame, Meteor, Evil Spirit, Ice Storm, Cometfall, Nova, Gigantic Storm and more.
  • High Elf / Noble Elf / Royal Elf – upgrades for Triple Shot, Multi‑Shot, Ice Arrow, Elf buffs, Summons.
  • Dimension Master / Dimension Summoner / Endless Summoner – upgrades for Drain Life, Chain Lightning, Sleep, Weakness, Innovation, Explo, Requiem.
  • Duel Master / Magic Knight / Duple Knight – mixed upgrades for sword + magic skills.
  • Lord Emperor / Empire Lord / Force Emperor – upgrades for Chaotic Desier, Fire Burst, Fire Scream, Earthshake, Raven.
  • Fist Master / Fist Blazer / Bloody Fighter – upgrades for Chain Drive, Dragon Roar, Dragon Slasher, Dark Side.
  • Mirage Lancer / Shining Lancer / Arcane Lancer – upgrades for Harsh Strike, Magic Pin, Breche, Spinning Slash.
  • Grand Rune Master / Majestic Rune Wizard / Infinity Rune Wizard – upgrades for rune spells like Shining Peak, Fire Burst, Electric Surge.
  • Master Slayer / Slaughterer / Rogue Slayer – upgrades for combo dagger skills and dash attacks.
  • Master Gun Breaker / Highest Gun Breaker / Magnus Gun Crusher – upgrades for gun skills like Triple Shot, Dark Phoenix Shot, Focus Shot.
  • Light Master / Shine Wizard / Luminous Wizard / Glory Wizard – holy/light magic upgrades.
  • Warmage / Archmage / Mystic Mage / Battle Mage – chaos magic and hybrid melee + magic upgrades.
  • Illusion Master / Mystic Knight / Phantom Pain Knight – hybrid sword + illusion magic skill upgrades.
  • Alchemic Master / Alchemic Force / Creator – elixir, homunculus and magic upgrades.
  • Master Paladin / Sacred Paladin / Templar Commander – upgrades for hammer & shield skills such as Holy Sweep, Divine Fall, Sacred Impact and support auras.
Rule of thumb: Choose 1–2 main attack skills for your build and max their Strengthener + Mastery nodes in Category 3. That will usually give better results than spreading points into every possible skill.

How to Build Your Master Skill Tree (All Class Types)

Below are simple, practical priorities for different playstyles. They work for both official‑like and most custom Season 20 & 21 servers.

Melee classes (Dark Knight, Magic Gladiator, Dark Lord, Rage Fighter, Grow Lancer, Slayer, Illusion Knight, Crusader)

  1. Category 1 first (survival basics)
    • Max SD Increase and Defense Increase.
    • Add a few points to Auto HP / Mana Recovery.
    • Take Defense Success Rate Increase if you are squishy.
  2. Then Category 2 (damage)
    • Attack/Wizardry/Curse Increase for your class.
    • Attack Success Rate Increase to reduce MISSES on high‑level mobs.
    • Critical & Excellent Damage Rate, then Attack Speed.
    • Weapon Strengthener/Mastery for your main weapon (2H sword, spear, mace, scepter, etc.).
  3. Finally Category 3 (class skills)
    • Max Strengthener + Mastery for your main combo skills (e.g. Twisting Slash + Death Stab for DK/Crusader, Chain Drive + Dark Side for RF, Harsh Strike + Magic Pin for GL, etc.).
    • Pick utility masteries (stuns, slows) if your server uses them.

Magic classes (Dark Wizard, Rune Mage, White Wizard, Lemuria Mage, Summoner)

  1. Category 1 – Mana & Protection
    • Max Auto Mana Recovery & Max SD.
    • Take Defense Increase and some HP Recovery.
  2. Category 2 – Wizardry & Crit
    • Wizardry/Curse Increase, Crit Rate, Excellent Rate.
    • Skill‑specific Strengtheners for core spells (Poison/Flame/Evil Spirit/Nova, etc. depending on class).
  3. Category 3 – Main Spells
    • Pick 2 main attacks for PvE (for example Evil Spirit + Meteor, or Chain Lightning + Drain Life).
    • Max their Strengthener and Mastery nodes.
    • Take any key buffs (Soul Barrier, shields, offensive auras) as mastery nodes if available.

Ranged & hybrid classes (Elf, Gun Crusher, Gun‑type builds)

  1. Category 1 – survivability & move speed
    • Defense, SD, Auto HP/Mana.
    • Some resistances if you plan to PvP.
  2. Category 2 – Attack & weapon masteries
    • Attack Increase, Attack Success Rate.
    • Bow/Crossbow/Gun Strengthener and Mastery.
    • Crit & Excellent Damage Rate.
  3. Category 3 – AoE & single‑target skills
    • For Elf: Triple Shot, Multi‑Shot, Ice Arrow, main buff enhancements.
    • For Gun Crusher: spread points into your main farming shot and your PvP skill.

Support‑style builds (Buff Elf, DL support, Alchemist, some Summoners)

  • Take Category 1 defensives first (you must stay alive).
  • In Category 2, invest enough damage to farm solo, but don’t neglect Party Buff & Aura masteries in Category 3.
  • Some servers add special master skills that increase buff duration or buff power – those are extremely valuable for party play.
General rule: When in doubt for PvE, spend points in this order: 1) Survival (Cat.1) → 2) Generic damage (Cat.2) → 3) Your 1–2 best skills (Cat.3).

How to Reset Your Master Skill Tree

If you make a mistake or want to change your build, you can reset the Master Skill Tree using Scrolls of Oblivion. Starting with MU EX700 (and used by many modern servers), there is a series of quests called “Deleting Memory”.

Deleting Memory quests (Skill Tree reset)

Talk to Shadow Phantom Soldier in Lorencia, Noria, Elbeland or Devias and look for the Deleting Memory quests:

Quest Requirement Reward What it resets
Deleting Memory – First Master Level 10+, kill specific mobs for Green Ink & Parchment of Soul Scroll of Green Oblivion Category 1 points (Protection / Peace / Blessing / Guardian / Solidity / Determination / Willpower)
Deleting Memory – Second Master Level 10+, kill mobs for Blue Ink & Parchment of Soul Scroll of Blue Oblivion Category 2 points (Bravery / Wisdom / Salvation / Chaos / Fighting Spirit / Justice / Determination)
Deleting Memory – Third Master Level 10+, kill mobs for Red Ink & Parchment of Soul Scroll of Red Oblivion Category 3 points (Anger / Overcome / Storm / Honor / Ultimatum / Conquer / Destruction)
Deleting Memory – Last Chance Master Level 50+, collect more inks Scroll of Gray Oblivion Resets ALL Master Skill Tree points

Many newer servers also sell Sealed Scrolls of Green/Blue/Red/Gray Oblivion directly from Ruud NPCs (like Priest James) for Ruud, instead of running the quests. Check your server’s Ruud shop.

Safe reset trick: If you are not sure about your new build, take a screenshot of your current tree before using a Scroll of Oblivion. If the new build feels bad, you can rebuild the old one from the screenshot.

Conclusion

Master Level and the Master Skill Tree are the core of late‑game progression in MU Online. Once you reach level 400 and complete your 3rd class quest, your focus should move to:

  • Farming Master Levels in maps and events that give good Master EXP.
  • Carefully building your 3 Master Skill Tree categories to match your class and playstyle.
  • Using Scrolls of Oblivion when you want to try a new build.

Combine this Master Skill Tree guide with your Class Quest Guide, Upgrade Guide and class‑specific build guides on MUOnline.ai to plan your entire journey from level 1 to 5th class.