Listen-Kill (aka L-K or LK) missile technology is an upgrade to missiles (both LRM and SRM) to improve their accuracy. This is achieved through a small computer and homing device in the missile's head that allows it to home in on the electronic noise of a BattleMech or tank. While very successful at first, the effect of L-K technology was quickly negated by jamming equipment tailored to counter it.
Although L-K missiles are generally considered to have been introduced only in 3038 by the Federated Commonwealth, prototypes were used as early as April 3029 by a mercenary unit in the employ of the Lyran Commonwealth, the Kell Hounds (together with the Crescent Hawks), in the defense of the Kell Hounds base on Lyons against attackers from the Draconis Combine. They managed to prevent the technology from falling into enemy hands.
The first large-scale deployment of L-K missiles occurred against the Draconis Combine by Federated Commonwealth forces during the War of 3039. Several Federated Commonwealth defense industries had pooled their resources to produce them in 3038. However, although effective, L-K missiles were still far too expensive and rare to be used as standard loadout, and did not have a significant impact on the outcome of the war.
Following their use in the War of 3039, the Draconis Combine was quick to develop a plug-in ECM module that totally countered the effect of L-K missiles. It was being distributed to their line units by summer 3039 already. Furthermore, they also reverse-engineered the L-K technology and had it available for themselves as well from July 3039 onwards. AFFS and LCAF were thus forced to also develop similar ECM technology in turn, which they had available by 3040.
It was not until 3042 that the New Avalon Institute of Science found a way to mass-produce L-K missiles. In the same year, the Draconis Combine provided samples of the missiles and ECM gear to the Free Worlds League and the Capellan Confederation to rekindle the Concord of Kapteyn.
By the mid-3040s, L-K missiles were common, but almost all units in the Inner Sphere were equipped with ECM gear to negate their effect by that time. Since L-K missiles are still more expensive than standard missiles but have essentially lost their advantage, it is largely a moot technology afterward (except perhaps against very old 'Mechs without ECM refit).
 Game Rules
- L-K missiles can be loaded on any LRM or SRM launcher
- When firing L-K missiles, the launcher has -1 to-hit bonus against any non-Clan units without ECM upgrade
- L-K technology cannot be combined with any other type of missile submunition (such as Inferno, Artemis, NARC, Thunder-LRM, etc.)
- ↑ 1.0 1.1 1.2 1.3 1.4 Historical: War of 3039, p. 144, "Listen-Kill Missiles"
- ↑ Crescent Hawks Revenge, computer game (apocryphal)