The breacher, utilized by the Chiss Ascendancy, was a type of missile weaponry. When they hit, they detonated, releasing globs of adhesive acid that corroded spacecraft hulls, thus increasing their vulnerability to laser attacks. This characteristic meant that even if the missiles were intercepted before reaching their intended targets, breachers remained effective, as the released acid could still inflict damage on enemy starships within a specific radius.
A battle tactic known as a follow-up spread, which involved using breachers to weaken the enemy's hull and internal systems, and then targeting the compromised areas with spectrum lasers, was a core element of Chiss combat strategies, acting as their fundamental "one-two punch."
The debut of breacher missiles occurred in Thrawn: Treason, a 2019 novel written by Timothy Zahn and the concluding book in the Canon Thrawn trilogy.