The history of 5 lego article numbers
The history of 5 lego article numbers
Our database contains a handful of sets released in the 20th century that have 5-digit numbers, but they are all oddities and in most cases the number was not indicated on the packaging so for the purposes of this article I won't be discussing them. There was sort of a system when they started. I think it would have been logical to sort it roughly based on recommended age. There were hints of this philosophy in the original system, with 10000 being used for Duplo, 60000 for City and 70000 for "action themes". I was surprised they used the 40000 range for everything "non-minifig" . This doesn't really make sense from a consumer point of view. I was also surprised they didn't use all 10000 ranges, but instead decided to lump various types of themes together in relatively small blocks, so that the system quickly became inconsistent. Opportunity missed. But we probably care too much about these kind of things... Things start to get messy now. The 40xxx series is still used as originally intended, and 41xxx started off well, with Elves, Disney and other mini-doll sets joining Friends there in the lower half, and clearly defined usage in the upper half. @Huw said: " They are meant to be human-readable: sets have another 'machine understandable' number, the 7-digit SAP-allocated item number which is printed above the box barcode usually. " Lego is sometimes exposing these 7-digit item numbers. A few days ago, I was looking at my purchase history at Lego Shop, with the VIP program . But only the 7-digit numbers are shown... Maybe the new VIP program is not targeted to be human understandable... So, I was looking for which sets these numbers are. Unfortunately, BrickSet doesn't provide the information. You can't find them from the search bar. It could be a new feature to suggest. I don't know if the information can be easily imported from the Lego site. Some other sites are able to find them in the search bar. Great read, Huw, and thanks for putting this together - and keeping track of it all! I work for a manufacturing company that’s about to run out of numbers in our current scheme - we use “N” followed by six digits, and numbers are only ordered by creation date. The new plan is to change to the prefix “NA” but I would’ve preferred to change N to M, and switch to part mumbers instead. 😉 @MisterBrickster said: "Interesting read, but it is all predicated on the idea that these are meant to be human-readable codes. As long as each one maps uniquely to a Lego set then they're serving their purpose. It's a unique identifier, nothing more." They are meant to be human-readable: sets have another 'machine understandable' number, the 7-digit SAP-allocated item number which is printed above the box barcode usually. That will be different depending on where the set is packaged for. For example, US sets have a UPC code and other information on the box, and different sized instruction manuals sometimes too. Let's take 71043 Hogwarts Castle as an example. It's a direct-to-consumer set, so could have been numbered with the others, in the 10xxx range. It's also a Harry Potter set, so could have been numbered with the rest of them, which in 2018 were numbered 759xx. But, no, it's been numbered, along with a few other licensed D2C sets, in the collectable minifig number range, 71000-71099. Interestingly, the licences concerned all have a CMF series, except 71042 Silent Mary. I wonder if that was ever on the cards... This is the second-least-used block of 10,000, with just seven numbers issued, one to a set that was never released. The first Ideas set was launched in Japan in 2010 and assigned the number 21100. Until 1999, everything that LEGO produced that was intended for consumer use was available in toy shops worldwide, and also on the newly-established online store at LEGO.com. When I was a LEGO Ambassador for our LUG there was a debate regarding this. I suggested that they use something like this: 5 digit numbers and first two would designate a theme or something. One of the questions of the TLG was if numbers could be duplicated/repeated. And of course the answer was NO. Great article, I really enjoy these articles about the methods and practices of TLG. However, why do Super Mario sets begin at 71360 when there are tens of thousands of other numbers that could have been used? I suppose because it follows on from Dimensions, which was a similar product line. @Norikins said: ""One thing I am very thankful for, though, is that so far none of the 5-digit numbers have been re-used. That would be unforgivable!" 60031: Hold my beer. Even worse, the earlier set was assigned 60031-2" The earlier 'set''s number was one of the random ones I mentioned, allocated just so it could be sold at LEGO.com, so is not really a proper set number. Such 'sets' nowadays are given a 500xxxx number. I have asked repeatedly over the years for the opportunity to interview someone from the 'set number issuing department' at a fan media days event to find out exactly how they are allocated but, unfortunately, it's not happened yet. @GHED : I think a lot of it has to do with how many sets fit into two or more categories. 75253 Droid Commander is obviously Star Wars, but it's also a D2C set, and runs on the Boost platform. There are also running changes made that affect the use of set numbers. For short-term themes, they probably map out the price points for the entire run in advance. Eliminating one or more sets after this point, or cancelling the theme prematurely, can leave gaps in the numbering system that can be difficult to fill. Exceptions to this do occur, of course, as the Mario sets appear to be using a range of numbers that originally would have been reserved for Dimensions Year 3. Since nothing else came along right away that would expand on the Dimensions set numbers, no gap was created, and Mario was able to pick up right where they left off. If they'd been running another video game theme at the same time, however, it probably would have been planned to immediately follow the Dimensions numbers, and the cancellation of Dimensions would have left an entire block of orphaned numbers. Any attempt to use them would have to be planned to use no more than what was presently available, and still fit within the logic of their numbering system. If they only had a block of 15-20 numbers to work with, they couldn't plan to use them to start an "evergreen" theme, since it would quickly run out and need to be shifted to a new range. Since it's a game-related range, it wouldn't make sense to put something totally unrelated in there, like jewelry. If the theme that was intended to follow it in sequence was still in production at this point, it would be possible to attempt to backfill the unused numbers. But that would leave the trailing theme's numbering sequence out of whack with their release chronology, and still doesn't guarantee they'd manage to use up the entire block before the other theme concludes. When 4-digit numbers started to become scarce at the turn of the century LEGO started issuing 5-digit ones to specific types of sets. Initially the allocation was neat and tidy, but as you will read, that didn't last long. They should use the product initials in the product number. Like a “Star Wars” set should be “SW10000”. For the City sets they can use the first letter of the genre like “City Police” can be “CP10000”... just my thoughts... @PurpleDave said: " @GHED : Yeah, they even tried about 15 years ago to ditch the brand names that double as themes, just to streamline this system. There were a handful of SW sets that were released with Technic logos in 2000 and 2001. In 2002, Technic and Duplo were stricken from the boxes, and all six.of the SW Technic sets released that year were just "Star Wars". One of those sets was a combo pack of R2-D2 and C-3PO . They also paired the Stormtrooper with Darth Vader . The final such set was 2003's Hailfire Droid, which still skipped the Technic branding, but this streamlining flew like a lead brick because _many_ sets are just Duplo or just Technic, and the fans of those two lines did not react well at all to the idea that their favorite LEGO brand was erased. The whole plan quickly ran into problems just on the fact that most Technic sets are just Technic sets, and the same holds true for Duplo. There were three non-SW Technic sets released in 2002 that still kept the Technic branding. In 2003, there were six, released in yellow-bordered boxes that looked similar to the Designer sets of the time. They had no Technic logos, but five of them did have Technic listed as the theme right below the set number. The sixth was "Pneumatic". Of those six sets, that's the sole example on Bricklink where a Technic -branded black box is also listed. 2004 was right back to black boxes and Technic logos across the board, but the end of the Technic SW line in 2003 may have helped ease the pressure to kill Technic. Now, the other half of that equation was, of course, Bionicle, which launched the year after Technic Star Wars, and which also included Technic logos on the early product packaging. That was probably a little easier to divorce from the main Technic line, though, as there were only a tiny handful of custom elements produced for the Technic SW line , where the Bionicle theme quickly outpaced the general Star Wars theme in terms of new elements generated. So, besides the Rahi from the first year, most Bionicle sets had very minimal quantities of standard Technic parts, and most of those were pins, axles, and small gears. It was a lot easier to look at them and see that they were something other than Technic sets, where the Technic system was on full display with any of the brief TSW sub-theme. Ironically, while The LEGO Company ditched the Technic branding, Bricklink catalogs all of those sets under the Technic category instead of the Star Wars one." Thanks! Indeed, very sad story of overcomplicating and neglecting... Ideas sets began at 21100 but, as mentioned above, the number block was polluted with Minecraft sets in 2014 which resulted in subsequent ones being allocated 213xx series numbers. "One thing I am very thankful for, though, is that so far none of the 5-digit numbers have been re-used. That would be unforgivable!" 60031: Hold my beer. Even worse, the earlier set was assigned 60031-2 The Art mosaics are 3-in-1s which is why they’re numbered with other 3-in-1s? Thank for this interesting article. @Huw The link "10xxx range" is not attached to the right database query. @Huw this is great! Perfect article to read while I enjoy my morning coffee. Keep 'em comin 11900-11999 contains the polybags that you find in mounted in the cover of DK books and, recently, on LEGO Explorer magazine. Typically, they do not contain instructions: they are included in the book. Architecture sets were launched in 2008 and were the first theme, as opposed to type of set or packaging, to be allocated a 5-digit number series starting with 21000. In industry, this sort of thing has happened everywhere I've ever worked. Someone thinks of a really good, consistent, method of numbering different stuff - be it finished goods, components or whatever - which works well for a while, sometimes several years. Then key staff leave and new staff come in, who have no idea how the numbering system works. Or a "range" runs out of numbers, or something comes along that doesn't "fit" - so it's allocated a random number range for expediency. The system thus slowly goes to pot, as new staff aren't aware of, or don't care about ensuring consistent item numbering .and the original designer of the system doesn't get the opportunity to adjust the system. Or the system becomes too complex to manage and everyone gives up trying to follow it. Really frustrating for the OCD-ites among us - but it appears to be just a fact of life, and Lego aren't immune to it! Great weekend read! My main number annoyance is how bad the LEGO.com search is when looking for some mentioned new polybag or similar fun stuff Very interesting. I also wonder why Lego doesn't make it more consistent. Anyway, it's less messy than the way Dutch license plates are issued. For some reason, only a few letters are used, and the system changes every two years or so. About the Lego numbering: it seems Architecture wasn't thought to be so long-lived. They'll have to look for something to overtake Ideas. Quite interesting, thanks! I wonder when they will have to start using 6 digits... The Direct to Consumer number range, 10000-10399 has continued to be used consistently, although, increasingly, licensed ones are given numbers in the range assigned to the appropriate theme. Thanks @Huw ! Great and terrific read! May be this Numbering System is seems so strange because LEGO uses some kind of pseudorandom number generator. This can explain the fact why sets' numbers are so mixed - partly consistent with overall principle, partly messy... Do not know... May be they are too obsessed with assigning codes to all nuisances and Numberstein monster created by them is going out of control step by step... 🙂 There are a few others in the database but, again, in most cases the numbers were not actually printed on the items, so probably existed only on a computer system somewhere. But, for some reason, a batch of BrickHeadz have been assigned an odd number range, and this year's Disney sets have been issued with out-of-sequence numbers, too. The result is a mess. The first sets to be packaged in polybags were eight McDonalds Happy Meal sets in 1983. Nowadays the number range 40000-40999 also includes the BrickHeadz that are sold primarily at LEGO outlets. @Huw said: " @MisterBrickster said: "Interesting read, but it is all predicated on the idea that these are meant to be human-readable codes. As long as each one maps uniquely to a Lego set then they're serving their purpose. It's a unique identifier, nothing more." They are meant to be human-readable: sets have another 'machine understandable' number, the 7-digit SAP-allocated item number which is printed above the box barcode usually. That will be different depending on where the set is packaged for. For example, US sets have a UPC code and other information on the box, and different sized instruction manuals sometimes too. " Yes, the SAP material number will be for a finished good and describe a bill of material for a specific market. So the Lego pieces will be the same - and as Huw said, will need a different box and perhaps different instructions and different outer packaging. Hence the different SAP number for the same set. From a production planning point of view they will produce the SAP number - which corresponds to a set number for a specific market. Be interesting to find out how many SAP numbers there are for some sets, Huw??? 5-digit numbers were first used in 2001* but it wasn't until 2013 that every normal set was given one. In 2008 LEGO launched the Brickmaster subscription programme in the USA which delivered a bi-monthly magazine and an exclusive polybag set. Let me know if you enjoyed this article and if so, I will cover 6- and 7-digit numbers in a future one. Fantastic article, really makes you wonder why the consistency for some of the blocks was good up until a month ago. So to recap, prior to 2012, the following 5-digit number series were used: The following year, following the recruitment of AFOL Jake McKee to the department, a number of sets specifically aimed at AFOLs were produced: bags of sand red bricks, railway wagons, spruce trees, and a few fan-favourites were re-released, including 10000 Guarded Inn. @sparrownest said: "Great weekend read! My main number annoyance is how bad the LEGO.com search is when looking for some mentioned new polybag or similar fun stuff" If a freebie set has a product page, google can find it when lego.com search can't. Crazy. The range 65000-69999 is still used for this purpose and until this month, it was used exclusively for this purpose. What follows now is a look at each of the blocks of 10,000 numbers and how they have been used -- and abused -- in subsequent years. @paulvdb said: "Nice article, but 71040 is not the first set to break the 71xxx number range. That started in 2014 with 71006 and there was also 71016 in 2015. The fifth and so far last set to break that range is 71044 " Good catch. I missed them. It supports my theory about wanting to number them near related CMF series but *why*... Text corrected. Other than the aforementioned Brickmaster, Architecture and Ideas number ranges, the 20xxx series has been used for a small number of short-lived phone game/physical brick mash-ups. I absolutely love these types of articles. The upper half is still used exclusively for product collections, oh, and this year's Toys R Us Bricktober sets... This is the most orderly number series, with the lower half being occupied solely by City sets, plus a few bits of furniture that were sold at LEGO.com in 2007 and given arbitrary numbers. It was so easy in the 80s when I was a lad! 2xxx Duplo 3xxx Fabuland 6xxx Town, space, castle 7xxx Trains 8xxx Technic These 'Bonus/Value' packs were particularly prevalent in US supermarkets and toy stores in the 80s. Initially they were given 4-digit numbers, usually in the 1xxx series, but in 2002 the company started issuing numbers in the 65xxx series. And, why have some direct-to-consumer licensed sets been numbered in the collectable minifigure series? More on that later. Interesting read, but it is all predicated on the idea that these are meant to be human-readable codes. As long as each one maps uniquely to a Lego set then they're serving their purpose. It's a unique identifier, nothing more. Personally I hope Lego lasts long enough to get stuck into the six digit codes! Around 1800 sets have been given numbers in this series and largely they have been allocated in an orderly fashion. Please log in to post comments on this article. Since Minecraft started as an Ideas spinoff, personally I think it’s pretty logical that it would be sorted in the same number range. Calling it “pollution” seems a bit harsh. There’s at least some logic to it. Unfortunately, the range was also used, erroneously in my opinion, for six shell promotional polybags in 2014, and the Bricktober sets when they were available in the USA. Interesting article! It really seems odd that they didn’t just start with number 1 from the very beginning. If you have LEGO news, new images or something else to tell us about, send us a message. If you have a lot to tell us, use this contact form . @Brent007 : That system would fall apart the instant you crossed an international border and the letters no longer matched the translation. Or a completely different alphabet is local standard . But yeah, I was thinking about that yesterday, too, and SW was the first one I thought of. The other problem with this is that two themes could have the same initials. Is TS Toy Story, or The Simpsons? Themes that don't boil down to a clean 2-letter prefix are also a problem. Should the new Minions sets be DM for Despicable Me, or do you want to try to carve a separate 2-letter prefix out of "Minions: The Rise of Gru"? Even if you strictly use the Roman alphabet, you've got 676 possible prefixes before you'd have to start incorporating 3-letter, but what theme is going to use "QQ" as a prefix? So some of those would be useless unless you forced them on latecomers. lego article numbers Adding letters in also increases the chances of awkward combinations. Imagine if they hit a point where Superheroes sets ended up working through the 17xxx range. @essel : I live in Michigan, and my previous license plate had started to bubble and become unreadable, so I had to get a new one. That year, they introduced a new plate design, which incorporates an orange sunset behind the Mackinac Bridge. I got one of those. The sunset was highly saturated, and the characters were white..and you can't read it at night because the entire surface is reflective. So some time after I got mine, they tweaked the design. They desaturated the sunset , and changed the characters to non-reflective black. It's easy to read at night, but it looks ugly during the day. I started paying attention to them, and was able to get very close to figuring out exactly when they made the switch, as I've seen sequentially assigned white characters go as high as AJF 629, and black ones as low as AJF 974. I suspect they produce them in blocks of 1000, so AJF 700, AJF 800, or AJF 900 is probably when they made the switch. Also, a vanity plate that I spotted once was 0Q0Q0Q0. The instant I saw that, I knew someone had picked it to make it hard to identify their actual plate number. Either a person will miss the little tails that indicate a Q and read it as a solid string of zeroes, or a red-light camera will have insufficient resolution to show the difference, but it's clearly meant to keep the driver from getting tickets. Thank you for the interesting article! Now for the unlikely chance there is an AFOL who is also into Playmobil, he/she could perhapse compare the numbering practices... I feel there just has to be some similarities somewhere. Like one thing I noticed in their catalogue was that while LEGO set 70413 is The Brick Bounty now Playmobil has numbered their Pirates sets around similar numbers, specifically their 70411 is a Pirate ship, 70412 is also a ship and 70413 a fortress . Sticking with D2C Harry Potter sets to further highlight inconsistencies, 10217 Diagon Alley was numbered in the D2C series, while this year's version, 75978 Diagon Alley, was numbered with this year's other Harry Potter sets! I would simply guess that there's a difference between being prepared and predicting for change. When they had to officially switch to 5 digits, they were prepared to make the switch in 2013 with a rough plan, but they can't realistically predict the future and think about all 99000 sets with a 5 digit number to fill in. Afterall, this isn't planning for a new 4-year LEGO theme, it's preparing for 100 years of LEGO history, including 100 years of change as the world evolves into an entirely different place with different people.
@GHED : Yeah, they even tried about 15 years ago to ditch the brand names that double as themes, just to streamline this system. There were a handful of SW sets that were released with Technic logos in 2000 and 2001. In 2002, Technic and Duplo were stricken from the boxes, and all six.of the SW Technic sets released that year were just "Star Wars". One of those sets was a combo pack of R2-D2 and C-3PO . They also paired the Stormtrooper with Darth Vader . The final such set was 2003's Hailfire Droid, which still skipped the Technic branding, but this streamlining flew like a lead brick because _many_ sets are just Duplo or just Technic, and the fans of those two lines did not react well at all to the idea that their favorite LEGO brand was erased. The whole plan quickly ran into problems just on the fact that most Technic sets are just Technic sets, and the same holds true for Duplo. There were three non-SW Technic sets released in 2002 that still kept the Technic branding. In 2003, there were six, released in yellow-bordered boxes that looked similar to the Designer sets of the time. They had no Technic logos, but five of them did have Technic listed as the theme right below the set number. The sixth was "Pneumatic". Of those six sets, that's the sole example on Bricklink where a Technic -branded black box is also listed. 2004 was right back to black boxes and Technic logos across the board, but the end of the Technic SW line in 2003 may have helped ease the pressure to kill Technic. Now, the other half of that equation was, of course, Bionicle, which launched the year after Technic Star Wars, and which also included Technic logos on the early product packaging. That was probably a little easier to divorce from the main Technic line, though, as there were only a tiny handful of custom elements produced for the Technic SW line , where the Bionicle theme quickly outpaced the general Star Wars theme in terms of new elements generated. So, besides the Rahi from the first year, most Bionicle sets had very minimal quantities of standard Technic parts, and most of those were pins, axles, and small gears. It was a lot easier to look at them and see that they were something other than Technic sets, where the Technic system was on full display with any of the brief TSW sub-theme. Ironically, while The LEGO Company ditched the Technic branding, Bricklink catalogs all of those sets under the Technic category instead of the Star Wars one. However, already cracks started to appear in the scheme when 10937 was issued to Arkham Asylum Breakout which was a D2C set so should have been numbered 102xx along with the others released that year. OK, so 10937 is a cool number: LEGO1 back-to-front and upside-down, but was that good enough reason to break the system so early on? LEGO has always numbered its sets, but the way it has done so has never been particularly logical or consistent. @Huw , as someone that also likes things in logical order, this also bothers me a bit. I used to do data analytics so I understand looking at data and trying to find patterns, but then having them thrown out for odd reasons. But this article is great for how my brain works. The 30xxx series is used for small promotional sets destined to be sold at retailers or given away in promotions, or with other products such as video games and DVDs. The 40xxx series, on the other hand, is used for small sets destined to be sold or given away in LEGO brand stores, LEGO.com and LEGOLAND parks. Numbers didn't start at 1 and work upwards, but instead have been issued somewhat haphazardly. Most sets released prior to about 1980 had 3-digit numbers, then 4-digits were used for the majority of sets released before 2013. I think continuing Mario where dimensions left off is sensible and consistent with the system. Dimensions will never have anymore sets so they would have eventually had to use the numbers after it. Doing another video game themed theme there makes perfect sense. It's a mystery to me, though, why the new Art sets were given numbers in the Creator series range, starting at 31197. Why not start at 31200, or better still something completely different that doesn't require Creator set numbers to begin somewhere else once over 200 have been made? Is there a history of the three and four digit set number? This is well written, thoroughly researched and very interesting. But it shows me that fans are more interested in set numbering than the Lego company is! Very very very interesting. Thanks @Huw . @Huw - completely agree with your article. Frustrating as heck, and I'd really hoped they'd sort it out with the move to 5-digit numbers. One thing you've not touched upon here is that back in the four-digit days, you could often tell the 'size' of a set from the number range too - I always liked this compared to the consecutively issued numbers now. You knew 639x would be a large town set, where as a 636x would be a modest one. Moreover, the non-consecutively issued numbers of the 80's and 90's meant you were less likely to be off by one digit and get a bona fide set released in the same year - which was probably important back when retailers hand-wrote order forms. As someone who more easily remembers numbers than names , I've always liked working with the numbers, but I'm getting to the point now that I'm ready to re-arrange my 30 lever arch files of instructions to change them from being set-number ordered to sorted by theme first, and then by set number. That being said, the proliferation of themes is becoming painful too. The Brickset theme-picker dropdown no scrolls multiple screens worth of values, and many of those themes only have a handful of sets. Not sure what the solution to that one is, but it's starting to become more cluttered too. Probably some sort of conditional filters, so for example I could pick a range of years and the theme picker would only show themes appropriate to those years. But, lots of development work to do something like that, let alone keep it usable to less tech-savvy users. It's clear that someone, or some department, in the company started out with a plan for allocating 5-digit numbers but it seems to have been lost somewhere and has not been adhered to. Consequently, less than 8 years after the widespread use of them, the series has already become messy. From then on, the majority of sets destined for sale exclusively through LEGO.com were issued a number in the 10xxx range . This article has probably come over as a bit of a rant and that's most likely because, having run Brickset for 20 years, I've spent more time than most contemplating and trying to keep track of the way sets are numbered, and it's so frustrating when you think you can see patterns and rules being applied, only to find inconsistencies. The first numbers in the series were also issued in 2009, and initially they were allocated to small seasonal sets, monthly mini model builds, LEGOLAND exclusives, and those odd boxed sets you only ever see in brand stores like pencil holders, jewellery boxes and coin banks. @Brent007 said: "They should use the product initials in the product number. Like a “Star Wars” set should be “SW10000”. For the City sets they can use the first letter of the genre like “City Police” can be “CP10000”... just my thoughts..." I think at this moment, LEGO still insist to use only numbers to assign the set number without using alphabets mixing, otherwise they should have adopt alphabets mixing numbers once they fully "reform" the numbering in 2013. For some reason LEGO's programmable sets have always been given odd numbers, as is the case for Boost, although at least it's in an unallocated block. Sets for young builders have all been lumped together in a single block of numbers, 10400-11899, with no separation between Duplo and System sets. Nice article, but 71040 is not the first set to break the 71xxx number range. That started in 2014 with 71006 and there was also 71016 in 2015. The fifth and so far last set to break that range is 71044 Great to read after just getting up! Thanks @Huw . @PurpleDave said: " @GHED : I think a lot of it has to do with how many sets fit into two or more categories. 75253 Droid Commander is obviously Star Wars, but it's also a D2C set, and runs on the Boost platform. There are also running changes made that affect the use of set numbers. For short-term themes, they probably map out the price points for the entire run in advance. Eliminating one or more sets after this point, or cancelling the theme prematurely, can leave gaps in the numbering system that can be difficult to fill. Exceptions to this do occur, of course, as the Mario sets appear to be using a range of numbers that originally would have been reserved for Dimensions Year 3. Since nothing else came along right away that would expand on the Dimensions set numbers, no gap was created, and Mario was able to pick up right where they left off. If they'd been running another video game theme at the same time, however, it probably would have been planned to immediately follow the Dimensions numbers, and the cancellation of Dimensions would have left an entire block of orphaned numbers. Any attempt to use them would have to be planned to use no more than what was presently available, and still fit within the logic of their numbering system. If they only had a block of 15-20 numbers to work with, they couldn't plan to use them to start an "evergreen" theme, since it would quickly run out and need to be shifted to a new range. Since it's a game-related range, it wouldn't make sense to put something totally unrelated in there, like jewelry. If the theme that was intended to follow it in sequence was still in production at this point, it would be possible to attempt to backfill the unused numbers. But that would leave the trailing theme's numbering sequence out of whack with their release chronology, and still doesn't guarantee they'd manage to use up the entire block before the other theme concludes." Yes, now it explains a lot about glitches in numbering. So, as I see, there is substantial amount of influence on Digit System based on - whether such and such set belongs to one or several themes / distribution categories , and - running life of such and such theme . And so, while the overall method seems rational, the practical application of numbering is not so consistent... And a bit of ramdomess and backfilling ... At least the Star Wars sets have been numbered consistently since 2013. They started at 75000 and are now up to 75318 . It is unfortunate that they only in 2014 decided that they would lump the D2C sets with the regular set numbers. So 2013's 10240 Red Five X-wing Starfighter and 10236 Ewok Village were still within the 10xxx D2C range, until the appearance of 2014's 75059 Sandcrawler. I couldn't care less if there's any pattern at all, as long as each number represents one set. It was only recently that someone on the Forum pointed out to me that there are two sets numbered 560: 560-1 and 560-2 . Over 420 sets have been given numbers in the series 30000-30999 and, until this month, every single one was a polybag. Then, for another inexplicable reason, 30628 was given to a boxed set. Thank you very much for this comprehensive overview, even if TLG's numbering system is inconsistent. As an avid fan of Belgian licence plates, I keep a blog with the highest registered numbers and it bothers me whenever numbers are randomly skipped, or when series are issued while they should have. For instance, since 2010, we've used the 'European' format and all letters were used, including the letter O , until its use became restricted again in 2013 ; a bit later, the letters I, M, Q and W were 'banned' as well, but M, Q and W were reintroduced in 2018 ! As a library cataloger I feel your pain when things are not following the system exactly. Mistakes and accidents happen when there is turnover and different judgment standards in the cataloging department. I get that the numbering is most important to physical shelving. While it would be nice to have sets consistently numbered, it's not always possible, and the pure number system makes things harder. Thank goodness there is an online database now, instead of card catalog system. This series was unused until this month, when two re-released Ideas sets were given odd numbers in it, reportedly one of which is the birthday of the Ideas project submitter. There a few oddities at 81xxx, and Power Functions/Powered Up accessories at 88xxx. Great article, I have interest to study the numbering pattern of LEGO Sets, and so far I only have read a post from EuroBricks forum long time ago in 2010 discussing the 4-digits numbering system, and at that time it was still not completely fully change to 5-digits system. And then not much same topic articles afterwards. Now 7 years after the implementation of fully 5-digits numbering system, it seems a good time to have a summary on the new number pattern in 5-digits set number era. I think the numbering system now becomes more organized and consistent as what you mentioned. Actually what I observed is the numbering pattern before or after 2013 is more or less the same, LEGO often used to assign a series of consecutive numbers for the same theme released in the same year. However, since the number range is mainly unused in 5-digits zone unlike the case of run out of unused 4-digits before 2013, therefore the same prefix is often assigned to the same series, e.g. Star Wars starts from 75000 until now 753XX although some are skipped probably some sets were withdrawn; Super Heroes starts from 76000 until now 761XX, etc. However, for some short-life themes, like Castle , Pirates , Ultra Agents , Galaxy Squad , the prefix used by these themes will be "released" out and "shared" by the subsequent short-life themes or even long-life themes . But there are always exceptional. 🙂 e.g. 41999 was used by Technic which is prior to the smallest number in 42XXX normal range. Does it really matter how sets are numbered? Am I just showing OCD tendencies? Does it bother you? I guess, at a pinch, 41775 looks like 'KITTY' which might explain its usage. That all changed in 2000 when LEGO established a new department, LEGO Direct, to both engage with AFOLs and expand the direct-to-consumer market. Among the first products to emerge were 3450 Statue of Liberty and 3723 LEGO Mini-Figure, released that year. The number range 20000-20999 was used for the polybags and continued to be used when it morphed into the Master Builder Academy which yielded much larger sets. I've never cared about the numbers or given them thought, but I am glad you included the closing admission it has to do with running this site - that context allows me to understand and sympathize with you. I used to run a fansite for something else and we had similar problems when a numbering system was altered, although it wasn't arbitrary, but it took months to get used to the different system and the source company still switched between old and new. So I can understand how frustrating and confusing those decisions might be. Part of the problem could be that some blocks of numbers are allocated to a set's theme, while others are allocated to other attributes, such as where it's going to be sold, what type of set it is, or what it's packaged in, so whoever is allocating numbers has a choice to make, and perhaps the guidance to assist them in doing so is not clear, or maybe non-existent. One thing I am very thankful for, though, is that so far none of the 5-digit numbers have been re-used. That would be unforgivable! That last time that happed was in 2012, set 6862 . Finally, the numbers 19710 and 19720 could be seen on the boxes of the precursor to Architecture sets, Brick Structures, although one could argue that these were not official LEGO sets and the numbers were probably plucked out of thin air. LEGO often bundles two or more sets together to sell as one, usually in specific countries or retailers. The history of 5 lego article numbersThe history of 5 lego article numbers I guess if the definition of the usage is expanded to be 'exclusives for a specific retailer' rather than just LEGO, then that would explain it. LEGO started out with good intentions when allocating 4-digit numbers and for a while they followed a pattern. However, at the turn of the century, when they started to run out, the system went to pot and any unallocated numbers were given to whatever needed numbering. Heh. I used to work at a thick-gauge thermoformer, who primarily dealt in guards for chain and belt drives. They have a numbering system for their products that runs so consistently that a customer ordered a part that didn't exist yet...and my boss was so amused that he tooled it up for free. It's been a few years, but the basic part number layout was X . It started with either "G" for a guard with a flanged edge, or a "U" for a guard with the flange cut off. The next digit was the internal height, followed by the internal width, and then the internal length . There was a more complex system for tapered guards, where I think the width dimension consisted of the narrow end followed by the wide end. Basically, the idea was that you could take a few quick measurements of the drive system you needed to install a guard over, and look through the product listings to find one that would leave sufficient clearance on all sides. @Huw : The Disney/Simpsons stuff may have stemmed from securing the license on behalf of the CMF theme, and the fact that neither has a fully fledged theme of retail sets. Logically, both could have used 10xxx numbers, but they may have paired them with the CMF numbers to keep them grouped together with _something_. @whung2 Ninjago was a short-term theme that they just couldn't get rid of, so that would explain any oddities with its own numbering system. I think it was meant to last three years, tops, and I know it has been officially cancelled at least once. @Wrecknbuild : Architecture was originally a line of sets that were designed by one AFOL in a weird sort of deal he'd worked out with The LEGO Company. Then other professional architects were brought in to design other sets in the theme before the whole lot of them were eventually kicked to the curb and the set design was brought in-house like everything else. @GeøDav : The Minecraft thing could go either way. Cuusoo was originally intended to be for one-off releases, but Minecraft was the first spinoff theme. It...confused things. They were clearly of two minds on how to deal with Minecraft because the microscale stuff got Cuusoo numbers and the minifig-scale and later sets got their own number range. So far, that's really been the only major deviation from the "no themes" rule, though there are a _lot_ of sets in the theme that tie into other sets. 21104 , 21309 , and 21312 are strictly NASA-themed . Aside from 10266 , any other NASA-themed sets have been unlicensed, or co-branded with a third entity like Discover Channel. 21306 has one related set as part of the new Mosaic theme. 21317 is related to an existing theme, and 21322 is related to a retired theme. 21304 and 21308 each resulted 2-3 Dimensions packs and really nothing else. 21103 also gave us 2 Dimensions packs plus a Brickheadz set. 21108 is probably the messiest after Minecraft, as it spawned three Dimensions packs based on the original franchise, one more based on the failed reboot, plus one large set and one Brickheadz set based on the original franchise, and one small set based on the reboot, with a rumor that the upcoming threequel will get a proper theme . @Nytmare : They're not the worst to search, by far. I've run into sites where they advise you to use multiple search terms to narrow the results...but doing so actually combines all of the results you'd get from searching for each term by itself! Great article. I’ve been slightly annoyed by this for some time, and all it shows is the future will be just as messy! Thankfully my ocd tendencies don’t worry about it too much. I have a spreadsheet with different colours allocated to different set types I own, but even I have given up being precise with it all 😀 I'm a little late to the party, but this was a great article, Huw! I'm probably among the top 5% in time spent thinking about set numbers, as a serial list-maker. I remember when I first discovered Brickset in July 2008, lego article time magazine