Forum: scifi.stackexchange.com
Tags: <star-wars><r2-d2>
Title: Is there only one R2-D2 droid in the galaxy or were other R2-D2 droids made?
Question: I know there are different versions of R2 droids but are there multiples of each version of those droids? In other words were there any other R2-D2 droids manufactured in the galaxy or is there only one? For instance I can have the same model cellphone as someone else but my phone will have a serial number making it unique. Is this true for R2-D2 or is it the "D2" after the "R2" that makes the droid unique?

Answers:
sents: text: There were plenty of R2 type droids .
text: However, R2-D2 was a unique instance of that designation in existing canon .
text: Googling for "other R2D2 units|droids" returns nothing; as an extra proof.
text: However, conceptually, there COULD have been other R2D2 units.
text: As I noted in my answer here , according to canon (Pablo Hidalgo - Internet Content Provider for starwars.com - Q&A in Star Wars Insider #58 (Page 97); as well as Disney canon "Rogue One novelization) , the 4-letter designation is merely an owner extracting easy to use name from a much longer serial number.
answer_details: author: scifi.stackexchange.com/users/976/DVK-on-Ahch-To
score: 30
sents: text: From the various uses in canon, the "R2" part is normally the model number, and the "D2" portion is the serial number.
text: Other R2 units are seen on screen, as well as plenty of R5 units.
text: R5-D4 is the unit that blows its motivator in Ep IV, for example.
text: Other R2 units from starwars.fandom.com's R2-series_astromech_droid and R2 Category page includeR2-0,R2-4B,R2-5,R2-A3,R2-A5,R2-A6,R2-B1,R2-B3,R2-B4,R2-BDE,R2-C2,R2-C3,R2-C4,R2-C9,R2-D0,R2-D2,R2-D5,R2-D6,R2-D609,R2-D7,R2-D9,R2-E7,R2-F2,R2-F7,R2-J8,R2-K7,R2-KT,R2-L1,R2-L3,R2-M3,R2-M5,R2-MK,R2-N3,R2-P3,R2-PU,R2-Q2,R2-Q5,R2-Q5,R2-Q8,R2-QU,R2-R7,R2-R9,R2-RC,R2-RD,
text: R2-S4,R2-T0,R2-T7,R2-V0,R2-V6,R2-W3,R2-X0,R2-X2,R2-X3,R2-X9,R2-Y9,R2-Z1,R2-Z13,R2-Z4.
text: Of these named R2's, R2-D2, Both R2-Q5's and R2-KT are on film (KT is in clone wars, Q5 #1 in Ep V, #6 in Ep VI).
text: A very few Extended Universe materials have R2 units with non-conforming names, such as B3-TA in The Clone Wars Adventures video game.
text: A Similar list of R5-units is seen as well; R5-D4 is seen in Ep IV, blowing his motivator...
text: Several are seen on film, and they are quite popular in the Extended Universe materials.
text: It's also noted that some R2 units are in R5 chassis, to cover up the gaff in Ep IV where Luke calls R5-D4 an R2 unit, saying "Hey!
text: This R2 unit has a bad motivator!"
answer_details: author: scifi.stackexchange.com/users/1367/aramis
score: 14
sents: text: I believe that they are not unique and that there are many R2-D2s out there in the galaxy.
text: Lets assume that all R2 units have a R2-XX name where XX can be any number or letter.
text: That gives us 67600 possible R2 units.
text: Wookieepedia states that there are around 1.75 million planets in the Empire .
text: Which means only 3% of them would have an R2 unit anywhere on the planet.
text: For such a common droid it seems very unlikely that they'd constrain themselves to selling them in such small numbers.
text: My suggestion would be that it works more like a software versioning system.
text: (Major-Minor).
text: R2 represents the model D2 represents the version of the droid
text: There is then some specific serial number identifying each droid (presumably much bigger).
text: As to why they're not referred to by this unique version number?
text: Would you rather call your droid R2-D2 or R2-D2-57073805371805317857832075501?
answer_details: author: scifi.stackexchange.com/users/19592/Liath
score: 3
sents: text: Assuming that the names of R2 units follow the pattern R2-XX, where X is a character in A-Z or 0-9 (37 possible characters), there are 37^2 or 1369 possible R2-unit names, which certainly wouldn't be enough to make them unique across thousands of star systems.
text: My best guess is that people tend to use the model number as a name as a short-hand, much as Luke referred to R5-D4 by color when referring to it as 'Red'.
text: In fact, R2-D2 is usually referred to simply as Artoo, which is a specifier used as a generic for all astromech droids.
text: The interesting thing is that C-3PO introduces R2 as R2-D2, without any further specificity, indicating that either C-3PO is using the human naming convention, or that R2-D2 is in fact unique.
answer_details: author: scifi.stackexchange.com/users/8598/Barton Chittenden
score: 2
sents: text: It seems pretty clear that the answer is "yes", given the information others have dug up about the Star Wars universe.
text: I wanted to chime in and suggest how this could be possible while still allowing many droids.
text: As evidenced by aramis' list above, some of the units have more than one digit (R2-Z13, R2-D609), and some have only letters (R2-MK) or digits (R2-5, R2-0).
text: To me, this implies that "D2" is something akin to a hex number (or rather, at least base 36, since we can see "Z" being used).
text: "0xFF" is considered a number, not a letter designation, in hexidecimal; the missing numeral glyphs are replaced with letter glyphs.
text: The second half of the designation is probably a numeric serial number in base 36, starting at R2-0.
text: That gives us serial numbers in sequence:
text: R2-0, R2-1, [...]
text: R2-9, R2-A, R2-B, R2-C,
text: [...] R2-Z,
text: R2-10, R2-11, and so on and so forth.
text: If my math is right, that would make R2-D2 the 470th droid produced, and the highest droid number on @aramis' list (D609) is the 614,313th droid of that type.
text: The millionth R2 unit would be R2-LFLS, still pronounceable by humans in a hurry.
text: Bumping up to five digits would get you 60 million droids.
text: Considering that doesn't count alternate lines like the QT, R2-AG, or R2-R, (and considering that sci-fi writers have no sense of scale ),
text: I think that's more than enough serial numbers to be plausible.
answer_details: author: scifi.stackexchange.com/users/4237/Yamikuronue
score: 1
sents: text: There are dozens of R2-D2 units in the galaxy, otherwise 2-1B would not have his 'own' sw wiki page and 2-1B Medical Droid having its own.
text: If R2-D2 is a unique number then logic would say 2-1B is unique as well, but the medical droid in SW3 is apparently not the same one from SW5.
text: If there are several 2-1Bs in the SW Universe, there's probably a few dozen R2-D2s running around.
answer_details: author: scifi.stackexchange.com/users/11710/Ryan
score: 0

Summary of the answers:
There were many R2 type droids. Assuming that the names of R2 units follow the pattern R2-XX, there would not be enough variations available to make them unique across thousands of star systems. Also, if there are several 2-1Bs in the SW Universe, there are probably a other R2-D2s. The "R2" part is normally the model number, and the "D2" portion is the serial number.
There are many R2-D2 droids that exist — into the dozens.