Pentagram and Errtels in MU Online: complete guide to the elemental system

The Pentagram system is MU Online's elemental combat layer — introduced in Season 12, it adds a dimension of elemental offense and defense that transforms how the end-game character operates. It's complex, rewarding, and entirely absent from Season 6.

The Pentagram

What the Pentagram is:

The Pentagram is an equippable item introduced in Season 12:
→ Occupies its own dedicated equipment slot
→ Has 5 socketed slots, each corresponding to one element
→ Filling a slot: insert an Errtel of the matching element
→ Benefits: active as long as the Pentagram is equipped (always on)

The 5 elements:
1. Fire (red): offensive, direct damage boost
2. Water (blue): defensive, HP and survivability
3. Earth (green): balanced, mixed benefits
4. Wind (yellow): speed-related, attack and movement
5. Darkness (purple): special effects, debuffs, PvP utility

---

Pentagram quality tiers:

Like other items: Pentagram has quality levels
→ Regular Pentagram: base stats, lower bonus multipliers
→ Excellent Pentagram: better bonus multipliers for the same Errtels
→ The Pentagram itself can be upgraded with Jewels (same +level system)

Getting a Pentagram:
→ Drops from S12+ monsters and bosses
→ Available from specific S12+ combinations
→ Some servers: Ruud shop (Ruud currency)
→ Excellent Pentagrams: from high-end S12+ content

---

Pentagram slot configuration:

The 5 slots and their element assignments:
→ Slot 1: Fire
→ Slot 2: Water
→ Slot 3: Earth
→ Slot 4: Wind
→ Slot 5: Darkness

Filling options:
→ All 5 slots with different elements (balanced)
→ Multiple slots of the same element (specialized)
→ Example: 3 Fire Errtels + 1 Wind + 1 Darkness = Fire-specialized build

The "no Errtel" slot:
→ Empty slots: no bonus, no penalty (just unused potential)
→ Fill all 5 eventually — each Errtel adds to your power
→ Priority: fill the most impactful elements first

Errtels — the elemental gems

What Errtels are:

Errtels are elemental gem-type items that insert into Pentagram slots:
→ Each Errtel has one specific element (Fire, Water, Earth, Wind, or Darkness)
→ Levels 1-15: L1 is weak, L15 is the maximum power
→ Types within each element: Attack, Defense, or Utility
→ An Errtel combines: element + type + level (e.g., Fire Attack Errtel L7)

How Errtel level affects power:
→ L1: very small bonus
→ L5: modest bonus (noticeable but not transformative)
→ L10: significant bonus (real power increase)
→ L15: maximum power (among the strongest individual item bonuses in S12+)

---

Errtel types:

ATTACK Errtels:
Focus: increases offensive output
Effects include:
→ Increases elemental attack damage (flat or %)
→ Increases attack success rate
→ Increases critical damage chance
→ Elemental damage penetration (ignores some enemy resistance)

Best for: PvM farming, boss DPS roles

DEFENSE Errtels:
Focus: reduces damage taken
Effects include:
→ Reduces elemental damage received from that element
→ Increases HP or defense
→ Reduces debuff duration from that element's attacks

Best for: survivability in specific content (fire-heavy boss → Water Defense Errtel)

UTILITY / CONTROL Errtels:
Focus: special effects beyond damage/defense
Effects include:
→ Elemental debuffs on targets (slow, weaken, reduce defense)
→ Buff enhancements (amplify certain self-buffs)
→ Unique PvP effects

Best for: PvP (control effects win fights), specific boss strategies

---

How to obtain Errtels:

Primary sources (S12+ servers):

1. Monster drops:
→ S12+ end-game maps: specific monsters drop Errtels
→ Drop rate: low for high levels, moderate for L1-5
→ Farming: consistent end-game map farming is the primary method

2. Boss drops:
→ S12+ bosses: Phoenix of Darkness, Lord of Ferea, others
→ Higher chance of better Errtels (L5+) vs farming

3. Ruud shop:
→ Some Errtel tiers available from the Ruud Merchant NPC
→ Typically L1-5 range; higher levels require boss farming

4. Errtel crafting/combination:
→ Some servers: combine lower-level Errtels into higher
→ Example: 3x L5 Errtel → 1x L6 Errtel (server-specific combination)

5. Events:
→ Blood Castle, Devil Square in S12+: may reward Errtels
→ Special events: Errtel packages as rewards

---

Errtel upgrading:

Some servers: Errtels can be upgraded from one level to the next
→ Method: Chaos Goblin combination
→ Materials: multiple same-element same-type Errtels + Jewels
→ Result: one higher-level Errtel

Success rates:
→ Lower tiers (L1→L5): moderate success rates
→ Higher tiers (L10→L15): very low success rates, all materials lost on failure
→ L15: near-impossibly rare through direct upgrading (drop is preferred)

---

Errtel levels and rarity:

L1-L5: Common (regular farming produces these)
L6-L9: Uncommon (requires dedicated farming or good boss luck)
L10-L12: Rare (top-end boss farming, combination)
L13-L15: Very Rare (among the rarest items in S12+ servers)

On the market:
→ L1-5 Errtels: cheap (few JoB equivalent)
→ L10 Errtels: expensive (significant JoB equivalent)
→ L15 Errtels: extremely expensive (some of the most valuable tradeable items in S12+)

Pentagram configuration strategy

How to build your Pentagram:

Step 1: Identify your primary content

Primary PvM farmer:
→ Maximize the damage element most effective against your farming area's monsters
→ Fire is often most universally effective
→ Fill: 3 Fire Attack Errtels + 1 Wind Attack + 1 utility

Boss fighter (role in group):
→ Maximize the DPS element
→ Consider: what element does the boss resist? → choose a different element
→ Fill: high-level Attack Errtels of the most effective element

PvP specialist:
→ Utility Errtels become more valuable
→ Darkness element: unique PvP effects
→ Fill: 2 Attack + 2 Utility + 1 Defense (balance)

---

Step 2: Decide element specialization

All-in on one element:
→ Fill all 5 slots with one element (e.g., all Fire)
→ Bonus: some Pentagrams give set bonuses for filling the same element
→ Downside: vulnerable to that element's counter

Spread across elements:
→ Use different elements for different bonuses
→ Bonus: diverse benefits
→ Downside: no single-element set bonuses

Mixed with matching:
→ 3 of one element + 2 of another
→ Often the optimal balance

---

Step 3: Prioritize Errtel level over quantity

1 L10 Errtel > 5 L5 Errtels in the same slot
→ The level bonus is exponential, not linear
→ Prioritize upgrading one Errtel to the highest possible
→ Then fill the rest with what you have

---

Pentagram for each class (general):

Dark Knight:
→ Earth Attack + Fire Attack combination
→ Reasons: Earth for sustained hits (DK hits often), Fire for burst
→ Defense: Water Defense in the 5th slot for survivability

Dark Wizard:
→ Fire Attack dominant (most elements boost Nova's type)
→ High Fire Errtel level: most important investment for DW
→ Wind for attack speed (faster casts)

Fairy Elf:
→ Wind Attack (speed-based, matches AGI Elf's rapid shooting)
→ Water Defense (Elf is fragile, defense helps survival)
→ Support Elf: less critical — focus gear budget on other slots

Magic Gladiator:
→ Fire + Earth combination (hybrid matches MG's hybrid damage)
→ Physical MG: Earth focus
→ Magical MG: Fire focus

Dark Lord:
→ Fire Attack (Fire Scream is fire-element for thematic alignment)
→ Darkness Utility (DL's control role in PvP)

Summoner:
→ Darkness Attack (matches Summoner's dark-magic theme)
→ Darkness Utility (debuff enhancement — complements Summoner's curse skills)

See also the Season 12 overview (the season when Pentagram was introduced), the Ruud guide (how to earn Ruud for the Errtel shop), and the modern end-game guide (how Pentagram fits into S12+ progression).

Frequently asked questions