Deceptive decoys, in electronic warfare, interfere with the tracking or final guidance of an enemy threat. They can be simple expendables, such as chaff or flares, a more complex expendable such as the Australian Nulka, or a more intelligent possibly reusable, towed decoy such as the AN/ALE-55. There are free-flying decoys such as the unpowered and powered Israeli-developed TALD family decoys.
The AN/ALE-55 has an onboard radar transmitter, with a fiber optic cable running back to its aircraft's controller, the AN/ALE-47. The controller, in turn, can send directions to the decoy transmitters from all the onboard and remote sensors available to the aircraft. Earlier towed decoys, such as the AN/ALE-50, had to depend on their own onboard and limited radar processing.
Submarines may release acoustic decoys that are either simple deceptive noisemakers, or complex intelligent and independently moving decoys. Surface ships, under torpedo attack, can fire acoustic decoys from their deck-mounted expendables launchers, or use a towed decoy such as the AN/SLQ-25 Nixie.
A given device, depending on its means of use, may be deceptive or sacrificial. Deceptive tactics interfere with the general search capabilities of sensors, by such things as overloading them with false targets. A sacrificial decoy interferes with terminal guidance of weapons, making itself a more attractive electronic target than the true target it is protecting.