Honkai: Star Rail 3.4｜New Mechanism: Toughness Lock

"Break Team, the times are changing!"

Earth-shattering news! Break Teams are entering a cold winter! According to the latest intel from HSR Leaks, HSR 3.4 may introduce a new mechanic—Toughness Lock.

Break Team: "Huh?"

As for the specifics of this new mechanic, HSR Leaks will break it down for all Trailblazers below.

 

New Mechanism: Toughness Lock

Similar to HP Lock. If an enemy has Toughness Lock, after their Toughness drops to a certain value, attacks by characters & allies will not deal any Toughness reduction, like Apocalyptic Shadow Flame Reaver (2nd layer is locked).

Difference to Weakness Protected

• Weakness Protected cannot be applied during an ally's skill, only after the skill finishes. If the Toughness reduction of a single skill is enough, you can Break an enemy before Weakness Protected is applied.
• Toughness Lock cannot be circumvented.

However, some players have reported that when fighting the Apocalyptic Shadow Flame Reaver second phase, the second-layer Toughness bar does get reduced briefly before instantly refilling due to the mechanic. Does this mean that with sufficient Break efficiency, it’s possible to fully Break the enemy in one go and bypass the mechanic?

But that said, this mechanic is clearly designed to control combat pacing—and it’s undoubtedly targeting Break Teams!

 

Which Characters Are Hit the Hardest?

Character	Raison
Firefly	Firefly relies on high-frequency Toughness reduction to quickly break enemy Weaknesses, triggering Super Break DMG as her primary source of damage. The Toughness Lock mechanic directly counters this playstyle—once the Toughness bar is locked, Firefly not only fails to fully break the enemy but also loses the crucial "Break moment" Super Break DMG, severely disrupting her damage cycle.
Boothill	Boothill’s burst damage is concentrated at the moment of Break. If the enemy is locked, he can’t create new Break opportunities, leading to a significant DPS drop.
Fugue	Fugue’s kit revolves around post-Break effects, making them highly vulnerable to Toughness Lock: her core skills require Break activation, but the lock drastically reduces Break opportunities; her ability to control battle tempo through precise Breaks is weakened; she is overly reliant on post-Break damage, resulting in poor performance during lock phases.
Rappa	Rappa’s damage heavily depends on rapidly shredding Toughness and breaking Weaknesses to trigger Super Break DMG. When enemies are Toughness-locked, Rappa’s attacks can no longer reduce their Toughness, depriving them of Break opportunities. Additionally, if the mechanic changes further, Rappa’s skill of "ignoring Weakness resistance to Break" could become nearly useless.
RuanMei	As the core support for Break teams, Ruan Mei’s value also diminishes under Toughness Lock. Her Break Efficiency boost and Break Delay extension become ineffective when enemies are locked and her role as an enabler for Break-centric strategies is severely undermined.

 

Firefly’s New Skin! Could This Be a Turning Point?

Firefly, often regarded as the least environment-dependent character in Break teams, will indeed face some challenges if this mechanic goes live.

However, the fact that Firefly is getting a rerun + new skin in 3.4 suggests that Toughness Lock may not be universally applied—perhaps only appearing on specific enemies (e.g., the Apocalyptic Shadow Flame Reaver). Teams tackling that content usually rely on Castorice or the Herta comps anyway, where Firefly isn’t even a core pick.

LDShop speculates since MiHoYo is releasing a new Firefly skin, they probably won’t completely kill off Break teams. Who knows? This "cold winter" might just turn into a spring revival for Break Team!

As for details on Firefly’s new skin—while no official artwork has leaked yet, early rumors suggest a sailor-style outfit with white thigh-high socks and a short skirt.

 

Final Thoughts

With 3.4’s update just around the corner, we’re looking at an exciting lineup: Phainon, Archer, Saber, and Firefly’s rerun. Firefly mains, in particular, have her new skin to look forward to!

And for Trailblazers eager to pull, LDShop is offering insane HSR top-up discounts, ensuring your journey through the cosmos remains unstoppable!