Droid / Legends Droids , short for android s , or also called robots , were mechanical beings , often possessing artificial intelligence . They were used in a variety of roles and environments , often those considered too menial or too dangerous for humans and other species . Droids were also used in fields that required extensive specialization and knowledge , such as medical droids and astromech droids . Droids designed for combat were battle droids . Depending on the model and its corresponding purpose , droids were totally obedient , rugged , expendable , capable of vast memory recall , and mathematically precise . These characteristics made them well suited for many jobs , though the lack of independent thought in the cheaper , less advanced models limited their capability . This lack of autonomy was simultaneously a vast asset and a glaring weakness — an asset in terms of obedience and control but a massive drawback in terms of effectiveness . Designers faced a fundamental paradox — make the droids overly intelligent , and they might rebel ; yet make the droids not intelligent enough and they would be ineffectual . Customarily , droid names were often an arrangement of numbers and letters . Definition of a droid . The words " droid " and " robot " are generally taken to mean the same thing . However , the official definition of a droid is " a mechanical being with a self - aware consciousness , as distinguished from a computer by having a self - contained method of locomotion . " Classes of droids . There were five Classes of droids or Degrees of droids . They were used to classify droids . Droids were divided based upon creativity , intelligence , and capacity for independent thought . It also depended on the nature of work they were built for . Class one . Class one droids worked in the fields of mathematics , physics , physical sciences , and medicine . Although they had in - depth knowledge of their field , they were rarely programmed to apply their knowledge to everyday situations . Class one droids were considered little more than computers since all they usually did was perform calculations . They tended to be more expensive , on average , than droids in any other category . There were four subcategories of class one droids : Medical droids Medical droids treated patients , assisted doctors and surgeons , and worked in laboratories to develop and test new medicines . Unlike other class one droids , medical droids commonly practiced the art they were programmed with . Biological science droids Biological science droids studied the life of plants , animals , and minerals . Physical science droids Physical science droids worked in fields of physical science such as astronomy , cosmology , hyperphysics , and trans - dimensional quantum metaphysics . They studied phenomena found in the physical universe along with developing and testing theories . Mathematics droids Mathematics droids worked in the field of mathematics , making billions of calculations in short periods of time . Less sophisticated math droids were used as accountants . Class two . Class two droids were programmed for engineering and other technical sciences . They differed from class one droids because they applied the science to real - life situations . Class two droids were rarely equipped with Basic vocabulators , instead communicating through Binary . There were five subcategories of class two droids . Astromech droids Astromech droids could interface with most starships . Their primary purpose was to calculate hyperspace jumps , and most had other functions such as repairing starships or running some of their functions during flight . Exploration droids Exploration droids explored planets and tested them for natural resources . They were also used to explore asteroid fields , possible hyperspace lanes , and even deep space . They were valued for their analysis abilities . Environmental droids Environmental droids studied and influenced the environment . Engineering droids Engineering droids performed tasks in the fields of aerospace engineering , industrial engineering , material engineering , and more . Maintenance droid s Sophisticated droids like those that made technical repairs to starships were categorized as class two droids , while most other simpler repair droids were classified as class five . Class three . Class three droids were programmed to interact with humans . They were said to be the most advanced droids ever invented . There were four subcategories of class three droids . Protocol droids Protocol droids were programmed for diplomacy , often with the knowledge of millions of different languages and cultures . They were mainly used by ambassadors and diplomats . Servant droids Servant droids worked in private households as butlers , maids , or personal chefs . Tutor droids Tutor droids were programmed with extensive knowledge with which to tutor students . Child care droids Child care droids took care of and sometimes even protected children . Some were not much more than expensive toys , while others could shoot blasters while carrying their charge away from danger . Class four . Class four droids were programmed to fight . Almost all class four droids carried weapons . Armed combat droids were among the first droids ever created . There were four subcategories of class four droids . Security droids Security droids were used to guard businesses , households , and other buildings . Security droids carried nonlethal weapons or simple alarms . Gladiator droids Gladiator droids were designed to fight other droids or sometimes even organic beings for entertainment . Onlookers would watch as the droids fought to the death in the battle arena . Battle droids Battle droids were usually used in armies . They were easier and cheaper to create than an all - organic army . Many were quite durable , while others were nothing more than mass - produced cannon fodder . Assassin droids Assassin droids were used by assassins to eliminate their targets . Assassin droids were the only droids built specifically to kill organics . Class five . Class five droids were simple labor droids that did menial labor that no one wanted to do . Class five droids were the most often encountered droids . There were three subcategories of class five droids . General labor droids General labor droids did whatever tasks their owners wanted them to do , such as heavy lifting . Labor - specialist droids Labor - specialist droids specialized in one job . They did poorly at other things . Hazardous - service droids Hazardous - service droids performed jobs organics couldn ' t due to a hazardous environment . Droid types . Droids were categorized by function , though the lines between categories were often blurred . Many droids , such as members of the BD - 3000 series , served a variety of roles and purposes , making classification difficult . Other droids , especially those who were " one - of - a - kind , " had unique capabilities and changing characteristics that made classification impossible . Some droids changed functions as they changed owners , sometimes many times throughout their operational life . These limitations notwithstanding , droids were grouped according to their primary factory - installed functionality . Assassin droids . These droids were used to kill specific targets , often those too well guarded for approach by conventional means . Typically deployed by bounty hunters , assassin droids were often tasked with suicide missions — missions with almost zero probability for successful escape . In addition to their expendability , assassin droids could be programmed with advanced targeting algorithms , allowing them to be more accurate than even the best sentient sniper . Not all assassin droids utilized traditional weaponry , however — certain models , such as the ASN - 121 , could be outfitted with a number of different weapons or sensors , allowing for different tactics such as brute force attacks or stealthy penetrations . Because of the higher intelligence and independence required for droids of this type , rebellions were known to occur , though not very frequently . Astromech droids . Droids used for interstellar starships , astromech droids , were mobile multi - role droids capable of hyperspace navigation , systems monitoring / control , damage repair , and data storage . These droids had extensive databases of stellar systems and hyperspatial coordinates , which were necessary for faster - than - light travel . Astromech droids were also used in certain starfighter models , typically those with hyperdrives . They served a similar , though expanded , role — supplementing the ship ' s onboard computer systems and aiding the pilot in navigation , repair , and interfacing . More advanced astromech models could often pilot a small craft by themselves , blurring the line between an astromech droid and a pilot droid . Some astromechs , like members of the R2 series , were equipped with numerous features that expanded their functionality beyond navigation and repair , allowing them to become useful in almost any situation . Because of their emphasis in technical fields , astromech droids were not equipped with vocabulators or language programming ; instead communicating through a series of beeps and whistles known as binary . In addition to an astromech ' s factory - installed functionality , many of these droids were customizable — allowing upgrades to sensors , tools , software , and even basic hardware . Battle droids . Droids were used most commonly in combat - related roles , where they offered a plethora of advantages over organic units . Droids could carry heavy weaponry and shielding , move rapidly without tiring , analyze targeting and trajectory calculations instantly , and protect crucial systems by burying them deep inside the frame of the droid ( often featuring backup processing and multiple layers of redundancy ) . Droids could follow orders to the letter , taking risks no organic unit ever would yet still maintaining their calm precision . Most importantly , however , these droids were expendable — unlike sentients , the amount of time and energy it cost to assemble a droid was often a tiny fraction that of recruiting ( or growing ) an organic and training them . Built on massive automated assembly lines , like the ones on Geonosis , thousands of capable droids could be produced in a matter of hours . Because of these factors , droids were used extensively as military units , most famously by the Confederacy of Independent Systems . Despite these advantages , however , combat droids suffered from several drawbacks . Most importantly , in order to create total obedience and foil any chance of rebellion , droid units were often crippled with extremely sub - par artificial intelligence . This drawback was exemplified by the hideously poor A . I . of the B1 battle droid , which rarely served any purpose other than as cannon fodder . Also , many ( though not all ) droid units lacked the flexibility and manipulation capabilities of organic units , especially in terms of hand and finger use . Interrogation / torture droid . Another prime use of droids was to question prisoners , and if deemed necessary also torture them . Droid interrogators could be more effective than Human ones for a number of reasons : impersonal machines often increased the subject ' s fear , making him more likely to be cooperative ; droids offered a precise medical - based analysis of a subject ' s system and tolerances , and whether or not he was telling the truth , all of which could be exploited frighteningly effectively by integrated serums and other tools of torture . Additionally , subjects under interrogation by droids often directed their anger and fear towards the mechanized machines , not towards the actual captors . This was often followed up by a later visit from a " friendly " sentient officer , offering sympathy and establishing a friend - like relationship . Once a rapport had been established , often the subject would divulge secrets willingly , without requiring direct ( and sometimes ineffective ) coercion . Medical droids . Droids were also used in the field of medical science . They offered advantages over Humans in that they could be programmed with massive amounts of information , none of which would be forgotten , making them extremely cost - effective . Meddroids , as they were known , could store detailed records on hundreds of patients , in addition to exhaustive information on diseases , wounds , and infirmities . Medical droids could analyze wounds or diseases and automatically determine severity of injury , necessary medication , and possible side - effects ; all by utilizing sensors and extensive databanks . The emotional detachment of these medical droids was both a blessing and a curse — an advantage because droids did not let emotions interfere with their task , but a disadvantage in that patients could often feel alienated from an impersonal machine . These droids could also operate on patients , using built - in tool extensions and surgical implements . These arm extensions were often modular , allowing rapid change from one medical specialization to another ( e . g . from neurosurgery to pediatrics ) . Because of the high costs associated with comprehensive meddroids , some model lines ( such as the DD - 13 line or FX - 7 models ) were not as sophisticated and were usually used as assistants . These medical assistant droids offered some independent functionality but were meant to be used in cooperation with dedicated medical droids , or with organic physicians . Pilot droids . Droids were also used in piloting roles , both directly and indirectly . Some were used for atmospheric flight , while others were used for interstellar navigation . Droids were well - suited for piloting roles for several reasons : they could be programmed with detailed schematics of a ship , they would not panic when under enemy fire , they could maintain tight formations and execute precision attack plans , and , because of their close integration with the ship ' s computers , they could monitor and repair damage to the ship far more effectively than a Human . Because of their expendability , droid pilots did not require escape pods or other life support systems , saving cost and complexity on the ships they flew . Protocol droids . Droids that were used to handle diplomatic affairs , and aid in translation between various languages , were known as protocol droids . Like medical droids , protocol droids utilized massive databanks , being programmed with thousands of different languages and dialects . Protocol droids were equipped with aural sensors , to receive audio information , and processing units , to analyze and apply necessary programming . Because of their close integration with sentients , protocol droids were often given in - depth personality matrices , allowing for a variety of different personalities and behaviors through a process called metaprogramming . Scout droids . Droids were used in exploration and scouting roles as well , providing a cheap yet effective mobile sensor platform . Probe droids , often launched by the thousands , would use a one - shot propulsion system to reach the targeted area . Upon arrival , these droids would analyze the area with their powerful sensor arrays ; sending the results of the scan back to the droid ' s creator . Droids of this type were used in many roles : military reconnaissance , deep space exploration , and mineral prospecting ( primarily in asteroid fields ) . Other models were atmospheric - bound , relying on repulsorlift technology to move rapidly and traverse height differentials . Most scout droids carried a similar core loadout — a multiple - spectrum photoreceptor , a magnetic imaging device , a thermal imager , and signals transmission equipment . Some models featured built - in weaponry , such as a blaster , or expansion slots that could be used for a variety of additional sensors or weapons . Some droids also included a self - destruct mechanism to prevent acquisition by others . Because of their clearly defined role and the need to keep the cost per unit down , probe droids were given inexpensive processing units and relatively " dumb " A . I . This resulted in a lack of flexibility and systemic errors when confronted with unknown circumstances not outlined in the computer ' s parameters . These drawbacks aside , probe droids were very effective in their native role : providing inexpensive but broad sensor capability , regardless of climate , radiation levels , or hostile presence . Other uses . In addition to the primary roles outlined above , droids served in a myriad of other , more specialized functions : Legal status . Droids were typically treated as property . More advanced droids sometimes received proportionally more respect . Some protested the status of droids as slavery . This was a contentious issue , owing in part to the difficulty of assessing levels of artificial intelligence , and determining which droids if any could be considered properly sentient . Although emancipation of droids was a radical concept , some opposed memory wipes except for very simple droids . The Naboo considered higher level droids equal as fellow sentients . Under the Galactic Empire , no laws protected droids from abuse and those who showed them respect were looked upon as strange . During the Yuuzhan Vong War ( 25 ABY – 29 ABY ) , droids were targeted for destruction by the technology - hating Yuuzhan Vong invaders who saw them as abominations . During the Clone Wars , general dislike for droids was spoken of between clones and their generals , which would regular use such slang as " clankers " or " tinnies " to refer to them . Yperio Baobab and droid languages . The father of modern droid language was widely held to be Yperio Baobab , whose Bab - Prime revolutionized robotic communication in 200 BBY . The following is a brief chronological list of other droid languages , previous and subsequent . Bab - Prime was responsible , at least in part , for the droid tendency to develop a personality if not given frequent memory wipes . A hapless employee of the Baobab Merchant Fleet , in an attempt to create a new Bab - Prime algorithm , actually created a personality virus that ran rampant through the galaxy ' s droid population , exacerbating what was apparently an existing problem . Since then , administering memory wipes to droids became commonplace . Behind the scenes . The word " droid " is derived from " android " , which means " man - like . " Thus , the term does not strictly fit second - degree droids that have nothing common with humanoids . " Droid " is the exclusive term for every robotic entity in " Star Wars " . The word " robot " is used only for primitive ( Pre - Republic era ) droids . However , Luke Skywalker called C - 3PO and R2 - D2 " robots " on one occasion in . Droids ' legal rights are often a fiercely debated topic among fans . In one television documentary , George Lucas said that C - 3PO — and thus by extension all droids — had no soul . Early " Star Wars " Legends material sometimes spelled " droid " with an apostrophe ( ' droid ) , short for " android " . Trademark . George Lucas holds a trademark on the term " droid . " The miniature ' mech combat wargame " " was originally released under the name " BattleDroids " , but was renamed due to trademark issues with Lucasfilm . ' film " " ( 2004 ) contains a reference to Lucasfilm ' s droid with the large weapon of destruction , the Omnidroid ; an apparently unrelated killer droid of the same name also appears in " Star Wars Galaxies " . The credits of the film give a nod to Lucasfilm . From " Mickey News " ( 25 November 2004 ) : Verizon Wireless has licensed the term " Droid " for its line of based on the operating system . Motorola ' s late - 2009 Google Android - based cell phone is called the , and this line of phone has been expanded to include other Android - based phones released under Verizon . The term is used under license from Lucasfilm .