Support Gems
Attach supports to active skills, unlock four slots, read compatibility tags, and manage resource tradeoffs.
Support gems modify one active skill gem. They can add damage, speed, recovery, area, projectile behavior, ailment scaling, channel payoffs, shout utility, or aura effects. They are separate items with their own levels and experience. They do not have rarity or affixes.
The Support Gem Index lists all 80 support gems with exact level-scaled effects, requirements, conflicts, and compatible active skills.
Four slots per active gem
Support slots belong to the active-gem instance. Moving that active gem between automation slots, unequipping it, or trading it does not erase its unlocked-slot count.
| Slot | Required active-gem level | Gold cost |
|---|---|---|
| 1 | 1 | 1,000 |
| 2 | 5 | 10,000 |
| 3 | 10 | 75,000 |
| 4 | 20 | 500,000 |
No slot is free. A new active gem starts with zero unlocked slots and buys the first one at gem level 1. All four cost 586,000 gold together.
Unlocks are sequential and permanent. Only the active gem’s earned level counts for an unlock; effective levels granted by equipment or affixes do not bypass the gate. Mirrored active gems cannot change their unlock state.
Compatibility tags and delivery shape
Every support checks the active gem’s exact tags:
- Required tags: every listed tag must be present.
- Alternative tags: at least one listed tag must be present.
- Excluded tags: none of the listed tags may be present.
- Conflict group: only one support from that group may be attached.
For example, Increased Area requires area and hit. Falling Star qualifies, but Iron
Choir does not, because an aura does not carry hit.
A support also checks the skill’s delivery shape, and not only its tags. A support whose benefit needs a circle cannot reach a shape that has no circle. Area-resize supports fail on a strike, a charge line, and a beam channel. Repeat supports fail on a single-target strike and a charge line. The rejection reason names the shape: “A charge skill has no area to resize”.
Every enabled active gem keeps at least 12 compatible supports out of the 80.
The gem bench defaults to showing compatible loose supports. Switch to All to inspect incompatible gems and read the first failed requirement. One active gem cannot use two copies of the same support.
Attaching and swapping
Open Skill Gems, select an active gem, then select a loose support from the support pouch. Tap an unlocked support slot to attach it. Selecting an occupied slot detaches its support, and placing a support into an occupied slot swaps the items when both destinations remain legal.
Support loadouts can only be changed in the hub; attempts are blocked while a run is active. Attached supports must be detached before they can be sold or listed through the Auctioneer. A support instance can belong to only one active gem at a time.
Levels and experience
An attached support receives 35% of character kill experience from the same kill events as its active gem. Multi-hit skills do not grant extra support XP per hit.
Support magnitudes interpolate from their level 1 value to their level 20 value. Past level 20, gains continue at one quarter of the earlier rate and approach a fixed cap. Structural effects do not scale with level: an extra-projectile support always grants the same number of projectiles, while its damage penalty improves.
Mana cost and reservation
Most supports multiply the active skill’s mana cost. Multiple support multipliers combine multiplicatively, so four powerful supports can make a skill substantially more expensive. Channel multipliers apply to every tick. Aura multipliers apply to reservation instead of a cast cost.
Cost-reduction supports apply their separate reduction after the multipliers. Active mana costs have a minimum of 1. Aura reservation has a 5% floor unless Open Covenant explicitly makes the aura free. Blood Reservoir reserves life instead of mana and is rejected when it would leave no unreserved life.
Finding support gems
Active and support gems share the gem drop channel. When a gem drops, it has a 40% chance to be a support gem and a 60% chance to be an active gem. The chosen base must be within its character-level drop gate; gem bases up to four required levels above the character can enter the pool.
Loose supports live in the support pouch. They can be sold directly from the gem bench or
listed through the Auctioneer. Selling grants 10 + 5 × support level gold.
Building a four-support set
Start with the skill’s job, then pay for the result:
- Clearing: area, split, pierce, fork, chain, splash, or aftershock effects.
- Boss damage: focused damage, penetration, execute, distance, or channel-ramp effects.
- Sustain: lower mana cost, life leech, mana leech, or defensive on-use effects.
- Ailments: chance, damage, status effect, or faster damage-over-time delivery.
- Shouts: effect, reach, duration, cooldown, or boss and crowd conditions.
- Auras: effect, radius, reservation, guard, pulse, or positional conditions.
Do not judge a support from its headline bonus alone. Check the resulting mana use, reservation, action speed, range, damage penalty, and conflict group before committing all four slots.