In electronic warfare, a sacrificial decoy tries to "seduce" an enemy threat (e.g., a missile) to attack it, rather than the "less attractive" real target. In contrast, a deceptive decoy is intended to interfere with the threat's tracking or guidance mechanism, so it loses the target or fails to attack anything.
The AN/ALE-55 aircraft-towed decoy can operate in both modes. Obviously, sacrifice is the last resort. Aircraft equipped with the AN/ALE-55, which is deployed by the AN/ALE-47 expendables dispenser, may then release an additional decoy. Again, it is preferable that the decoy deceive rather than seduce.
Submarines can launch such decoys as the Long-Endurance Mobile Submarine Simulator (LEMOSS), which is built into a long-range torpedo housing, but carries an acoustic submarine simulator rather than a warhead. Ideally, it will seem enough like the real submarine that the enemy will attack it.