Diablo Immortal: How Auxiliary Gem Rank and Quality Caps Work

In Diablo Immortal, auxiliary gems can scale above Rank 1, but their effective combat affix rank is strictly capped by the rank of the primary host gem socketed into that gear slot. The auxiliary gem replaces only the legendary combat proc, while the host gem continues to provide all Resonance, Combat Rating, and gear awakening bonuses.

How the Host Gem Rank Cap Works

An auxiliary gem activates at its own rank or the host gem's rank, whichever is lower. The game never boosts an auxiliary gem above its actual upgrade level, nor does it allow an auxiliary power to exceed the host gem's rank.

Primary Host Gem Rank	Auxiliary Gem Rank	Effective Affix Rank	Inactive Auxiliary Ranks
Rank 4	Rank 2	Rank 2	0
Rank 4	Rank 6	Rank 4	2
Rank 6	Rank 8	Rank 6	2
Rank 10	Rank 4	Rank 4	0
Rank 10	Rank 10	Rank 10	0

If your host gem is Rank 6 and you insert a Rank 8 auxiliary gem, the legendary power functions at Rank 6 potency. The remaining two ranks on the auxiliary gem stay dormant until you raise the host gem to Rank 8. Conversely, slotting a Rank 4 auxiliary gem into a Rank 10 host gives you Rank 4 affix potency.

Quality Caps and Milestone Thresholds

Auxiliary gem affixes scale based on the auxiliary gem's inherent star tier (1-Star, 2-Star, or 5-Star/X-out-of-5). However, this scaling remains bound by the host rank limits:

Proc Value Scaling: If you slot a 2/5-Star auxiliary gem, its values scale according to 2/5-Star formulas up to the capped rank, not 5/5-Star values. Higher-quality gems (such as 4/5 or 5/5) transfer their superior affix formulas, but only up to the permitted rank.
Milestone Unlocks: Legendary gems frequently unlock bonus effects at milestone ranks, such as Rank 3 or Rank 5. If your host gem sits at Rank 2, an auxiliary gem cannot activate its Rank 3 bonus effect, even if the auxiliary gem itself is Rank 5.
No Quality Leeching: Placing a high-quality 5-Star gem into an auxiliary slot does not increase the star rating, Combat Rating, or Resonance of a lower-tier host gem.

Stat Distribution: Host vs. Auxiliary

When building around the auxiliary system, keep gem responsibilities strictly separated:

Primary Host Gem Dictates: Total socket Resonance, Combat Rating attribute increases, and gear awakening bonuses (such as skill damage bonuses and cooldown reductions).
Auxiliary Gem Dictates: The active or passive legendary affix (crowd control, damage shields, procs, or area-of-effect abilities) scaled to the lower of the two gem ranks.

Practical Upgrading Rules

To avoid wasted upgrade materials, follow these progression priorities:

Match host rank before upgrading auxiliary gems: Never spend gem fragments and duplicate copies leveling an auxiliary gem past your host gem's current rank. Extra ranks on an auxiliary gem provide zero combat value while the host lags behind.
Leverage budget awakenings: Leveling a 2-Star gem to Rank 10 gives access to gear awakening and reliable Resonance at an accessible cost. You can then slot a Rank 3 to Rank 5 five-star auxiliary gem into that slot to gain high-tier combat procs without sacrificing your Rank 10 awakening perks.
Swap auxiliary affixes for specific modes: Because the host gem preserves your baseline Resonance and Combat Rating, you can safely swap auxiliary gems to match content. Use offensive damage procs for PvE farming, and swap to defensive mitigation or crowd-control affixes for PvP encounters without disrupting your character's underlying core stats.