Subspace weapons are a class of directed energy weapons that affect subspace. These weapons were banned under the second Khitomer Accords due to their unpredictable nature. Among the effects that can occur as a result of these weapons are subspace tears.
Son'a vessels carried and used isolytic burst weapons, a type of subspace weapon. This was a direct violation of the treaty signed at the second Khitomer Accords. (Star Trek: Insurrection)
- The Starfleet-manufactured tricobalt device could also technically be classed as a subspace weapon, as it is capable of creating a tear in subspace, as revealed in VOY: "The Voyager Conspiracy". However, due to the high predictability of is subspace effects they may no bet classified as subspace weapons and therefore not banned by the Khitomer Accords. Though infrequently, they are sometimes carried on Federation vessels.