UNDECEMBER Rune List (2026): Skill Runes, Link Runes, Builds & How to Get Them

UNDECEMBER features a flexible rune system that lets players create their own combat builds without being restricted to traditional character classes. By combining Skill Runes, Link Runes, and Runestones, players can customize attacks, spells, damage types, triggers, summons, defensive abilities, and movement skills.

This updated UNDECEMBER Rune List covers the main rune categories, important rune names, recommended combinations, acquisition methods, and the latest changes introduced in 2026.

What’s New in UNDECEMBER Runes in 2026?

The current season, The Farside, launched on September 10, 2026, introducing new skills and significant improvements to Channeling builds.

The September update also improved several Channeling skills, including Flamethrower, Sacred Light, Domain of Strength, Sacred Devotion, and Enchanted Sentry. Some skills now allow movement while maintaining their Channeling effects, significantly changing how those builds play.

The October update introduced Transcendent Spell Activation on Attack Hit, a specialized Link Rune that connects compatible attack skills with triggered spells.

These updates are important because older rune guides may not include the latest Skill Runes, Transcendent Link Runes, or updated Channeling mechanics.

1. Understanding the UNDECEMBER Rune System

UNDECEMBER uses three major rune-related item types.

Skill Runes

Skill Runes are hexagonal and may support up to six Link Slots, depending on the individual rune. They can represent melee attacks, projectiles, spells, buffs, summons, movement skills, and other abilities.

Link Runes

Link Runes attach to Skill Runes through connected slots. A Link Rune only applies its effect when its color, tags, and other compatibility conditions are satisfied. Some runes have additional restrictions even when their colors match.

Runestones

Runestones enhance Skill Runes based on their positions in the Rune Cast. Up to three Runestones can be equipped, subject to overlapping-slot restrictions.

The official game guide confirms these distinctions and the six-direction linking system.

Rune colors and grades

The main Link Slot colors are Red, Green, and Blue. White Link Slots are special slots that can accommodate Link Runes regardless of color, although compatibility rules still apply.

The basic rune grades are Normal, Magic, Rare, and Legendary. Higher grades can unlock stronger effects and additional bonuses.

Important: Rune color is not enough to determine compatibility. Always inspect the rune’s actual tags and restrictions.

2. UNDECEMBER Skill Rune List

Skill Runes determine the primary abilities available to your character.

For practical reference, the following sections group established Skill Rune names according to their general roles. These are browsing categories, not exact in-game tag classifications, and some runes fit multiple roles.

Melee and close-range Skill Runes

These runes are associated with close-range attacks, melee combat, and weapon-focused damage.

Additional established melee-oriented rune names include Illusion Axe, Illusion Hook, Illusion Strike, Shield Charge, Frost Wave, Lightning Vortex, and Thorn Explosion.

Players should choose these skills based on weapon compatibility, damage type, attack speed, survivability, and whether the skill works well against groups or individual bosses.

Bow, projectile, and ranged Skill Runes

Ranged builds generally emphasize attacking from a distance, managing projectiles, and maintaining consistent damage while avoiding enemies.

Other ranged-related names include Aerial Throw, Wind Blade, Throw Explosive, and Shadow Forest.

The appropriate Link Runes depend on whether the chosen skill supports additional projectiles, piercing, chaining, splitting, or other projectile behavior.

Spell and elemental Skill Runes

Spell builds may use Fire, Cold, Lightning, Poison, Physical, or other damage mechanics.

For elemental builds, examine both the base damage type and the skill’s actual tags before choosing Link Runes. A projectile-looking spell does not automatically support every projectile modifier.

Summon, Rune Knight, and Abyssling Skill Runes

Summoner builds use companions to deal damage and support combat.

Summoner-related support skills also include Gather Minions, Sacred Devotion, Unite Crowd (Enrage), and skills that strengthen or coordinate summoned units.

Prioritize Minion Damage, Minion HP, summon-related skill levels, and relevant offensive mechanics rather than assuming ordinary player attack bonuses improve every summon.

Trap, Sentry, and Totem Skill Runes

These skills provide alternatives to conventional direct-attack builds.

Sentry builds benefit from Sentry-specific modifiers, while trap builds need effects compatible with trap installation, trigger behavior, and damage delivery.

Movement, defense, buffs, and seals

These Skill Runes are important for survivability and supporting a primary damage skill.

Additional established utility and support skills include Domain of Strength, Enchanted Sentry, Sentry Expert, Hazy Melody (Low Tone, High Tone), Intensify Pain, Wings of Ignition, and Electric Area.

The names above are cross-referenced against the community UNDECEMBER Runes Library , which provides filters for rune type, attributes, tags, and acquisition method. This community database is useful for discovering established rune names, but its index should not be treated as a fully synchronized record of the October 2026 game client.

3. New Skill Runes Added in 2026

Older rune lists may be missing several important 2026 additions.

The May and September release notes confirm the addition of these four Skill Runes.

Divine Punishment

Divine Punishment is a Lightning-based Channeling spell designed for sustained damage.

According to the September 2026 patch notes, it has the following characteristics:

• Tags include Spell, Area of Effect, Channel, Strike, Lightning, and Projectile.
• It creates a lightning field that strikes enemies within its area.
• Critical hits can produce additional enhanced strikes.
• At the documented base configuration, a critical hit has a 40% chance to trigger an additional enhanced Divine Punishment.
• Multishot, Parallel Shot, Pierce, Split, and Chain are not supported.

Build direction: Channeling-focused Lightning damage, critical hits, and compatible Channeling Link Runes.

Charged Shot

Charged Shot is a Physical bowgun skill built around charge stages and strong projectile attacks.

Key mechanics include:

• Tags include Attack, Charge, Strike, Physical, Projectile, Bowgun, and Overheat.
• It becomes stronger as charge stages accumulate.
• It provides projectile-related bonuses at different charge stages.
• Its projectile behavior includes piercing.
• Multishot, Split, and Chain are explicitly restricted.

Build direction: Bowgun-specific Physical damage, charge-stage scaling, and projectile-related modifiers that are permitted by the skill.

These restrictions are especially important: adding a popular projectile Link Rune does not guarantee that it will work with Charged Shot or Divine Punishment.

4. UNDECEMBER Link Rune List

Link Runes improve Skill Runes by modifying their damage, speed, resource costs, damage delivery, and other mechanics.

The community rune database currently indexes 192 Link Runes. Because recent updates have introduced additional Transcendent Link Runes, that figure should be treated as a database count rather than a definitive total for the live 2026 version.

Damage and offensive Link Runes

Other offensive Link Rune names include Strike, Smash, Slaughter, Killing Machine, Find Weakness, Spot Weakness, Improved Technique, Grand Approach, Overpower, Momentum, Fighting Spirit, and Opportunistic Strike.

Damage modifiers are not automatically interchangeable. For example, Attack Damage modifiers and Spell Damage modifiers affect different skill categories unless another mechanic explicitly allows their interaction.

Projectile and ranged Link Runes

These Link Runes are particularly relevant to bow, bowgun, and projectile-based abilities.

Projectile restrictions must be checked individually. Some newer Skill Runes, including Charged Shot and Divine Punishment, explicitly disallow certain projectile modifiers.

Status effect and damage-over-time Link Runes

The September 2026 balance update also changed status-effect interactions: Bleed no longer inherently ignores Armor, while Burn no longer inherently ignores Elemental Resistance. This is important when evaluating older Bleed and Burn builds.

Speed, resource, and general utility Link Runes

Some Link Runes add resource costs in exchange for higher offensive performance. The best damage-support choice is therefore not necessarily the rune producing the highest theoretical damage.

Minion, Sentry, Trap, and Totem Link Runes

Check the Link Rune’s restrictions before investing in upgrades. Many ordinary Attack or Spell supports exclude Minion, Sentry, Totem, and Trap skills.

Trigger Link Runes

Trigger Link Runes are among the most important advanced mechanics in UNDECEMBER because they connect compatible skills.

Established trigger-related names include:

• Spell Activation on Attack Hit
• Spell Activation on Spell Hit
• Spell Activation while Channeling
• Spell Activation upon Enemy Kill
• Spell Activation on Hit
• Buff Activation when Hit
• Buff Activation upon Crowd Control
• Buff Activation upon using Movement Skill

A trigger setup depends on the source skill, target skill, directional connection, trigger conditions, and applicable cooldown or resource rules.

5. Transcendent Link Runes

Transcendent Link Runes are special support runes with unique mechanics.

Several were added during 2026, including:

The January update identified the hidden Starlight Guardian boss in Wheel of Fate as a possible source for its newly added Transcendent Link Runes. This should not be assumed to apply to every Transcendent Link Rune released subsequently.

Transcendent Spell Activation on Attack Hit

This is one of the most notable October 2026 additions.

According to the official October 8 update, it has several important properties:

• Requires a compatible Attack/Strike activation skill and a target Spell skill.
• The target must meet specific tag restrictions.
• Trigger Chance is 100%.
• Activation is limited to a maximum of one trigger per hit when the activation skill is used.
• Transfers specified Attack damage and critical-related increases to the triggered Spell.
• Cannot be awakened.

At Link Rune Level 10, the official table lists 80% damage amplification for the activated skill and +2 Rune Levels, together with its other effects.

This does not mean every attack can trigger every spell. The compatibility restrictions remain essential.

6. How to Get Runes in UNDECEMBER

There are several ways to obtain Skill and Link Runes.

The exact source depends on the rune, its grade, and the current game version.

Buying runes from Mystic Pauline

Mystic Pauline is the primary Rune Shop NPC.

Players can purchase eligible Skill and Link Runes with Gold. The selection changes as the story progresses, and the official guide states that previous Acts’ purchasable runes become available after Act 6.

Not every rune is sold by Pauline, however. Some require alternative acquisition methods.

How to find the source of a specific rune

For the most dependable acquisition information:

1. Open the in-game Item Compendium.
2. Navigate to the Rune Compendium.
3. Select the Skill Rune or Link Rune you want.
4. Inspect its displayed information and use the Source Filter.
5. Confirm whether the rune is sold, dropped, rewarded, synthesized, or obtained through specialized content.

The Rune Compendium becomes available after the Act 2 quest Knight Captain’s Logic. It includes Skill Runes, Link Runes, and Runestones, along with source filtering.

This is preferable to relying on a fixed third-party acquisition table, because shop availability and content rewards may change between updates.

7. How to Upgrade Skill and Link Runes

Rune progression involves several separate systems.

Rune leveling

Skill and Link Runes can be leveled using Gold and Elements through the relevant rune-growth interface.

Higher rune levels generally improve the effectiveness of the underlying abilities or support effects. Players should prioritize their primary damage skill and the Link Runes that provide its most valuable scaling.

Rune grade upgrades

Rune grades provide additional effects as they increase from Normal toward Legendary.

However, the value of upgrading a rune depends on its particular grade bonuses. Upgrading a utility rune does not necessarily offer the same performance improvement as upgrading a primary damage rune.

Increasing Link Slots

More usable Link Slots allow additional compatible Link Runes to support a Skill Rune.

The maximum number of Link Slots depends on the skill, with up to six directions supported by the system.

Rune enchanting can modify slot counts, colors, and link positions. Always review the required Essence and the possible outcomes before using valuable materials.

Rune Awakening

Awakening grants a special effect to eligible runes.

The official guide describes three Awakening option families for Skill Runes:

The effect of each option varies by Rune. Players cannot assume Source is always better than Origin or Verity.

The official guide identifies Level 78 as the unlocking requirement for Rune Awakening and explains that eligible Legendary Skill Runes at Level 30 can receive Awakening effects.

Spica Essence: Advanced rune leveling

Spica Essence was introduced with The Farside season in September 2026.

Its major feature is that it allows eligible runes to progress beyond the previous level cap.

Spica Essence can be obtained through the new Agony Wave content, according to official season information.

Because failure can reduce a rune’s level, high-level upgrades should be treated as investments with risk rather than guaranteed improvements.

8. Recommended Rune Combinations by Build Type

The following are starting directions for choosing rune combinations, not guaranteed best-in-slot builds.

A useful rule is to select the main Skill Rune first, then build around its actual tags. Start with reliable damage scaling, address resource requirements, and add specialized mechanics only when they improve the build in real combat.

Choosing a beginner-friendly rune setup

New players can use a straightforward progression approach: select one primary damage skill, support it with compatible Link Runes, equip a movement skill, and add defensive or recovery skills as needed.

Avoid splitting limited upgrade resources across several unrelated damage skills. A focused setup is generally easier to upgrade and evaluate.

Choosing an endgame rune setup

For advanced builds, consider the entire damage system instead of only the main Skill Rune:

• Skill and Link Rune levels, grades, and Awakening effects
• Zodiac specialization
• Weapon and gear modifiers
• Critical or non-critical damage scaling
• Armor or elemental penetration
• Resource sustain
• Runestone bonuses
• Trigger interactions
• Boss damage and survivability

A build that performs well while clearing ordinary monsters may need substantial adjustments for high-level boss encounters.

9. How to Use the Rune Cast

The Rune Cast is the interface where Skill Runes and Link Runes are equipped and connected.

To set up a working Rune Cast:

1. Open the Skill menu or use the K hotkey on PC.
2. Place the desired Skill Rune in the Rune Cast.
3. Select the Skill Rune to inspect compatible Link Runes.
4. Equip Link Runes in connected slots.
5. Verify that each Link Rune effect is active.
6. Register the desired active skills in the available Skill Slots.
7. Test the setup and review its performance.

The official guide also explains that a Rune Cast can be expanded with Traum’s Crystal and Gold.

Rune Cast Presets in 2026

The September 2026 update added Rune Cast Presets, allowing players to save and load different rune configurations.

A preset records rune positions, trigger information, Runestones, and quick-slot configurations. The feature provides a default preset and allows expansion up to five presets using Rubies.

However, presets do not create duplicate runes or store independent copies. If a required rune is no longer available to the character, that part of the saved configuration cannot be restored automatically.

10. Common Rune Problems and Solutions

Remember that a connected Link Rune is not necessarily an active Link Rune. Matching its compatibility conditions is essential.

11. Frequently Asked Questions

How many runes are in UNDECEMBER?

There is no fixed count that should be assumed to remain accurate across every update. The searchable community library currently shows 365 indexed runes, including 192 entries under its Link Rune filter, but recent 2026 additions mean that count should not be presented as the definitive live-game total.

For the most reliable current collection information, use the in-game Rune Compendium.

What is the difference between Skill Runes and Link Runes?

Skill Runes enable abilities. Link Runes modify compatible Skill Runes by providing additional effects.

Can a Skill Rune have six links?

Some Skill Runes can support up to six Link Slots, but the permitted number depends on the specific Rune. Additional slots also need to be configured and compatible.

Where can I buy Skill Runes?

Eligible Skill Runes can be purchased from Mystic Pauline with Gold. Other runes require alternative acquisition sources.

Can I get runes through synthesis?

Certain runes may be obtainable through applicable synthesis systems. Check the relevant recipe and the Rune Compendium’s Source Filter instead of assuming all runes share the same synthesis method.

What are the best Skill Runes in UNDECEMBER?

There is no universally best Skill Rune. Effectiveness depends on the current balance patch, character investment, gear, Link Runes, Zodiac choices, and the content being played.

Is Divine Punishment available in 2026?

Yes. Divine Punishment was added with The Farside season on September 10, 2026.

What is the new Charged Shot Rune?

Charged Shot is a Physical bowgun attack added in September 2026. Its damage and projectile behavior are influenced by charge stages.

Can Link Runes be awakened?

Eligible Link Runes can use the Awakening system, but not every Link Rune supports it. Some special runes, including the October 2026 Transcendent Spell Activation on Attack Hit, explicitly prohibit Awakening.

How do I see every rune and its acquisition method?

Open the in-game Rune Compendium and use its rune and source filters. This is the preferred way to check a specific rune against the installed game version.