Base Delta Zero / Legends Base Delta Zero was the naval code used by the Galactic Republic and Galactic Empire to order the complete surface destruction of a planetary target , eliminating all life , industry , and natural resources on the surface . Similar actions were known to have been carried out by the Sith Empire and the Confederacy of Independent Systems . Characteristics . Defined as " the systematic complete destruction of all ' assets ' of production , including factories , arable land , mines , fisheries , and all sentient beings and droids " , Base Delta Zero denoted the most severe of several levels of destruction that could be directed against a center of resistance , and involved laying waste to an entire planet by orbital bombardment , reducing the upper crust of a planet to molten slag or in some cases , atomizing the planet ' s top - soil . A Base Delta Zero fleet bombardment was regarded as one of the most devastating operations that the Imperial Military was capable of , and unlike other Imperial military codes , the designation was not subject to change , so that there was never any confusion when it was issued . Due to its effects , BDZs were considered a last resort . History . Devastating planetary bombardments were recorded from the earliest millennia of galactic history . For instance , the Infinite Empire laid waste to Tatooine before the dawn of the Old Republic , and around 4000 BBY , Yavin 4 was devastated by firestorms created by Force energy , while the Sith forces in the Jedi Civil War obliterated Taris and Telos IV . But these atrocities paled before the power of a Base Delta Zero operation . Even hardened Imperial officers who were well versed in invasion operations found the tactic unsettling . Some saw it worse than destroying the planet outright . It is not known when the Republic Navy introduced the Base Delta Zero code , but during the Clone Wars , the order gained new notoriety when Republic fleets were used to destroy Separatist armies entrenched deep underground . Under the New Order , Base Delta Zero operations continued to be mounted primarily against targets that the Imperial Army had failed to gain control of by direct assault , but such missions acquired increasingly punitive overtones , being used against rebellious planets where the Empire judged a ground assault would incur too many Imperial casualties , or simply where forces were not available to mount a direct attack . As few as three " Imperial " - class Star Destroyers could execute such operations in a " matter of hours . " In 19 BBY , Imperial warships used the BDZ tactic on the planet Caamas . However , Imperial involvement was suspected only and could not be proven until the Caamas Document was discovered in 19 ABY . In 4 BBY , Moff Sarn Shild gave a Base Delta Zero command targeting the smugglers ' haven of Nar Shaddaa . This order was not carried out because of the Imperial defeat at the Battle of Nar Shaddaa . Another notorious Imperial - era atrocity , the bombardment of Emberlene , was often blamed on the Empire by the locals despite having nothing to do with it . At one point , the " Assertor " - class Star Dreadnought " Wrath " led a Base Delta Zero operation , which involved various TIE / D Defender squadrons , some " Imperial " - class Star Destroyers , and at least one " Interdictor " - class Star Destroyer . In addition to naval bombardment , army missions with the same objective as a Base Delta Zero command were undertaken to combat the enemies of the Empire . The mercenary unit First Sun Mobile Regiment was often hired by the Galactic Empire to destroy all enemy assets similarly to a BDZ bombardment . The Empire continued to use devastating bombardment tactics , for instance at Milagro , and some of these may have been Base Delta Zeroes ; but the New Republic rejected planetary bombardment missions outright , until Operation Emperor ' s Hammer during the Battle of Borleias in 28 ABY .