Cryo Rounds

Lore & Background

Kira joined the SASC after a series of high-altitude extraction operations where conventional suppression proved insufficient against heavily armoured targets. Her unit's research division was tasked with developing a non-lethal, rapid-deployment restraint method that could be delivered at range without the logistical overhead of a dedicated sidearm. The result was a line of supercooled ammunition that, on impact, triggered a localized phase change in the surrounding air, encasing the target in a brittle crystalline shell for just long enough to disrupt their momentum.

Within the broader Rainbow Six Siege world, Frost's cryo technology is rarely seen outside SASC channels. It is a niche tool—expensive to produce, limited in quantity per engagement, and most effective in confined spaces where a frozen enemy becomes an obstacle as much as a neutralised threat. Operators on both sides learn quickly: a single cryo round can turn a well-timed breach into a stalled, visible, and vulnerable moment of stillness.

Kira herself is known in SASC briefings for her calm, almost clinical delivery. She does not announce her rounds; she simply adjusts her aim, squeezes the trigger, and watches the frost bloom. In the lore of the Siege universe, she represents the quieter, more surgical end of defensive counter-terrorism—where the goal is not to overwhelm but to stop, hold, and let the situation resolve on your terms.

In Their Own Story

The corridor smelled of cordite and wet plaster. Kira pressed her cheek to the cold polymer of her rifle and listened to the boot-fall two floors up—three operators, moving in a tight wedge toward the reinforced door she had already marked with a thin line of frost.

She counted. One. Two. The first round left her barrel with a soft, almost silent *thwip* and struck the lead attacker's chest plate. The air around him crystallised in a burst of white, and he simply… stopped. Mid-stride. Mid-breath. His eyes went wide behind his visor as the ice crept up his shoulders, locking his arms at his sides.

The second operator froze in the doorway, half-turned, a breaching charge still clutched in his frozen fist. The third—smarter, faster—dropped low and scrambled for the window. Kira let him go. He was no longer a threat to the room.

She exhaled. Two rounds gone. One left. The ice on the first man was already beginning to spider with hairline cracks, and in a few seconds he would be moving again, confused, disoriented, his timing shattered. That was all she needed. That was always all she needed.

Reader's Guide

Cryo Rounds are carried exclusively by Frost (Kira), a SASC defender. She fires them from her primary rifle; each round, on hitting an enemy, encases them in ice and immobilises them for a brief window.

The tactical problem it solves is proactive area denial and breach disruption. Unlike a trap that waits to be triggered, Cryo Rounds let Frost actively interrupt an attacker's momentum the instant they commit to a push. A frozen enemy cannot throw, plant, or reposition, and their visible, stationary state gives teammates a clear target and a moment to realign. Because the rounds are fired from the rifle, they require no separate gadget slot or throwable animation, making the action fast and hard to predict.

Key interaction: a Cryo Round that strikes a destructible surface (a wall, door, or floor panel) temporarily freezes that surface, making it non-destructible for a short duration. This lets Frost lock down a breach point she has not yet reinforced, buy time for a teammate to deploy a shield or trap, or simply deny a hole that an attacker was about to create. The effect is temporary—the surface thaws and becomes vulnerable again—so it is a delay tool, not a permanent fix.

Because the rounds are limited per round, Frost must choose her shots carefully: a wasted round on a wall she does not need frozen, or a freeze on an enemy who is about to die anyway, is a resource lost. Pairing Cryo Rounds with her Cryo Grenade (a small AoE freeze) lets her cover both a direct line-of-sight target and a secondary angle in the same engagement.

Did You Know?

• Cryo Rounds are one of the few gadgets in the game that are fired directly from the operator's primary weapon rather than deployed as a separate throwable or placed device.
• A Cryo Round that hits a destructible surface temporarily makes that surface non-destructible, effectively 'freezing' a breach point shut for a few seconds.
• Frost is a defender whose gadget has an inherently offensive, disruptive character—she actively freezes advancing attackers rather than passively blocking them.
• The immobilisation effect on a frozen enemy is brief; once the ice cracks, the operator is free to move, throw, or breach again, making timing of the freeze critical.