The competition held last December was a great success with lots of awesome MOCs. We are running another one for April, with a similar theme. Create and submit a MOC using only the parts from any single set of your choice (that meets the criteria below). If your submission gets the most votes at the end of the month, you win $100!

There are two main differences from the last competition:

  1. You can pick ANY set to create a MOC out of, as long as it has between 150-300 parts and was released in 2013 or later. Here is the full list of 100+ sets you can choose from.
  2. The winner will be determined by a judging panel.



I am pleased to announce we have three expert AFOLs who have agreed to volunteer their time to judge the competition entries.

  1. Nathanaël Kuipers - Well known in the AFOL community, Nathanaël was a LEGO designer responsible for the design of several Technic sets from 2005 to 2008. He is also the author of The LEGO Build It Book. Not just a Technic whiz, Nathanaël has also created dozens of amazing Creator alternate models which you can find on his website.
  2. Jason Allemann - Jason seems to be the master of making viral MOCs. His creations range from amazing mechanical beasts and creative puzzles to humorous holiday scenes and videos.
  3. Attila (plastic.ati) - Ati is a master of alternate builds, with a seemingly endless number of creations, he has been a big contributor to Rebrickable.


  1. All parts in your MOC must come from a single set.
  2. You may pick any set you like as long as it has 150-300 parts and was released in 2013 or later.
  3. You must submit your MOC before the end of April 2014.
  4. Judging will take place in the first week of May and the winner announced in the forum.
  5. The judges will take into account many factors when scoring each entry, for example: originality of design, proportion of parts used, build quality/construction, playability, quality of instructions, etc. The scores from each judge will be added together and the entry with the highest total is the winner.
  6. Only a single entry per user will be considered for voting (you may submit multiple, but choose one as the final one).
  7. The MOC must be a new creation you have designed yourself.
  8. As these are alternate builds, please ensure your entry gives a 100% match before submitting. Entries that do not match may not be approved. See this help guide for details.
  9. Digital models are allowed, provided the parts are correct during submission (I would suggest leaving out any minifigs if submitting a digital model). Note however, that digital-only submissions may lose points in any sturdiness/construction analysis as it has never been built to verify it works.
  10. If you spot a mistake in the inventory for that set on Rebrickable, please let us know immediately via the Submit Change page.
  11. Submissions can be talked about on the forum during the month and it is encouraged to show off your creation.
  12. As with all MOCs on Rebrickable, your submission must have building instructions and a parts list. There are many acceptable forms of instructions, check out this guide to help you.

If necessary, please review the guide for submitting a MOC.

The winner will receive a gift certificate from their choice of either Amazon, eBay or shop.lego.com for the equivalent of US$100 in their currency of choice.

Update: The winner is MOC-1466 Shadow Wing!


  • 5 years, 6 months ago Ziepher (1769) MOC Designer
    So, how's the voting going? Looks like there have been no news on either the blog entry, nor the forum thread. Are the judges busy scrutinizing?
    • 5 years, 6 months ago plastic.ati (28K) MOC Designer ADMIN
      At least I am still checking (and building) some parts. I plan to finalize for the weekend.
  • 5 years, 6 months ago LE-GOlas (220) MOC Designer
    I am finally done with my MOC(The Orion)I spent quite a lot of time on it and I hope you guys like it as well.BTW how much do you look into a entry,just by picture?Or do you look into the instructions and details?
    • 5 years, 6 months ago plastic.ati (28K) MOC Designer ADMIN
      For myself I plan to build at least the critical looking parts in real. So to answer your question, we will check the entries for several differrent points of view.
  • 5 years, 6 months ago LE-GOlas (220) MOC Designer
    The parts for my entry won't import,could somebody help before it's too late?It says:ERROR: No Set-ID assigned yet. Please click the 'Save Details' button above to generate a Set ID. but I already did that.
    • 5 years, 6 months ago Nathan (64K) Site Admin ADMIN
      Refresh the page and try again? I'll look into it.
    • 5 years, 6 months ago plastic.ati (28K) MOC Designer ADMIN
      - check on the main page if you have MOC noted as (WIP / Work In Progress)
      - in case no "Save Details" didn't work (there was some problem with accessing rebrickable.com in the past few hours) so you have to make it again
      - in case there is MOC noted as WIP, check the Set-ID (like MOC-1234)
      - you can add parts for this MOC once the radio-button for its number is selected on the parts panel, or if you chose that MOC from the dropdown list.
  • 5 years, 6 months ago Waler (1543) MOC Designer
    I want to enter with my creation. I have to enter specific title, tags or something else to let you know that this MOC is for contest?
  • 5 years, 7 months ago LE-GOlas (220) MOC Designer
    I was wondering,if I included a bonus model in the instructions,do I include the pieces in the inventory?
    • 5 years, 7 months ago biodreamer (21K) MOC Designer PRO
      if you do a X in 1 MOC you need to include the minimum parts to build any of them. However it would most likley be treated as two entries so the bonus model won't give you any benefits in the contest. You will have to choose with which one you enter with. Also all models need to use the parts from the same alternate set.
      • 5 years, 6 months ago LE-GOlas (220) MOC Designer
        No,it's a model using the left over parts.
        • 5 years, 6 months ago biodreamer (21K) MOC Designer PRO
          In that case Yes. You can have any number of submodels in a MOC and if they are intended to build at the same time then all parts should be in the inventory.
          • 5 years, 6 months ago LE-GOlas (220) MOC Designer
            Thanks for helping.
  • 5 years, 7 months ago LE-GOlas (220) MOC Designer
    I see that a user named Bricksky has created two entries,both using parts from different sets,is this allowed?
    • 5 years, 7 months ago biodreamer (21K) MOC Designer PRO
      Yes you can submit any number of entries but you have to select which entry you want to compete with before the contest ends. You can see that I have done so in the previous contests. The hard part is selecting which of them you like best or in this case which one you think the judges will like best.
      • 5 years, 7 months ago LE-GOlas (220) MOC Designer
        What about using parts from different sets,is that allowed?Because in the rules it says all parts must come from the same set.
        • 5 years, 7 months ago biodreamer (21K) MOC Designer PRO
          No your not allowed to mix. you have to stick to within a set. or it wouldn't be a alternate build. Your are allowed to use the spare parts. We did have a issue with LDD files in the first contest after this, it was decided that it's your own responsibility to check that the file your submitting is only containing valid parts for the set. You can't trust external sources to use the right parts to recreate a set or that the LDD import is translating the parts correctly. ie patterns and molds may differ. There is a link to test this on the MOC submission page; below where you enter the alternate set you are using. if that link doesn't give you 100% you have a problem. Fix it before submitting the MOC.

          Note that it's okay for the instruction to show alternates mold,or pattern/sticker due to lack of parts in software but the Inventory should be correct when submitting.
        • 5 years, 7 months ago plastic.ati (28K) MOC Designer ADMIN
          Which means "all parts must come from the same set" for a single entry, so "using parts from different sets" is disallowed. (see rule #1)

          (More than one entries are welcome, but as biodreamer wrote, the MOC Designer must choose one before the session ends (see rule #6))
        • 5 years, 7 months ago LE-GOlas (220) MOC Designer
          The two entries from bricksky both seem to have parts from different sets: http://rebrickable.com/search?q=comp-apr-2014 (MOC 1426 and MOC 1492),just wondering if they were eligible.
          • 5 years, 7 months ago plastic.ati (28K) MOC Designer ADMIN
            Are you talking about the surrounding material and minifigs, or have you found something in the instructions? Any help would welcome, as I haven't checked yet, and making corrections in time would be better than disqualifying an otherwise good alt build.
          • 5 years, 7 months ago LE-GOlas (220) MOC Designer
            So I can make the surrounding out of different set parts?(sorry if I'm thinking to hard about this)
          • 5 years, 7 months ago plastic.ati (28K) MOC Designer ADMIN
            I think (but Nathan could answer this better) the photo/pic can contain surrounding material if one can easily pick the real MOC, however, the instructions should contain only the MOC, with all the bricks used in the MOC.
          • 5 years, 7 months ago Nathan (64K) Site Admin ADMIN
            I didn't explicitly state it in the rules, but I guess I have no problem with use of some extra background parts used to display the MOC in photos. As long as it is obvious that it is not included in the instructions and is not an integral part of the MOC.
          • 5 years, 7 months ago LE-GOlas (220) MOC Designer
            OK,thank you for taking the time to answer my questions.
  • 5 years, 7 months ago NickAb (10)
    Does new mean never submitted anywhere (e.g. flickr) before, or not yet submitted to Rebrickable?
  • 5 years, 7 months ago gev (1306)
    So I went to the LEGO store today to get a copy of 10674-1 - Pony Farm, since it's on the approved list and looks like fun regardless. However, upon casting my gaze upon the item in question, it clearly says "306 pieces"...

    Can I get a ruling on this?
    • 5 years, 7 months ago biodreamer (21K) MOC Designer PRO
      I am no judge in this but if there are 306 pieces in it. Rebrickable need to update the inventory. I would vote for allowing the set to be used, the inventory was incorrect when the contest started and people might order online and don't see the part count on the box. It would be unfair to disallow it. Beside I doubt six extra pieces will change anything especially when one of them is a brick remover.
    • 5 years, 7 months ago plastic.ati (28K) MOC Designer ADMIN
      As one of the judges I would say yes, you can use this set as it was on the list Nathan quoted as "Here is the full list of 100+ sets you can choose from." So I totally agree with biodreamer.
    • 5 years, 7 months ago DwBrick (2K) Set Manager ADMIN
      I added the missing pieces. Most of them are new colors for existing parts. They aren't available in lego pick a brick too (which explain the errors). If you own the set, please check the spares and please commit those parts in a change request for the set. Thanks
    • 5 years, 7 months ago Nathan (64K) Site Admin ADMIN
      Agreed - you can use this set for the competition.
  • 5 years, 7 months ago Legolijntje (28K) Inventory Admin ADMIN
    It says digital entries are allowed, but it may lose points for sturdiness. What if I enter a digital model, but including a picture of the real thing (in different colours for examlple, because I don't have them)?
    • 5 years, 7 months ago biodreamer (21K) MOC Designer PRO
      if you can build it with incorrect colors, you have a way to check sturdiness. But a picture of a incorrectly coloured version isn't good for anything. So you have to use a screenshot from the software you used to create it. So all you get is an entry that is more likely to win because its less likely to have flaws that would disqualify it.

      sturdiness is up to the judges to decide, not sure how they will do it if they actually build them or not.
  • 5 years, 7 months ago tamey (229) MOC Designer
    Can't wait to enter another alt. build contest! I'm glad you've changed the judging system, I think there were a few *cough* cheaters *cough* and the judges seem great choices.
  • 5 years, 7 months ago BEAVeR (3K) MOC Designer
    I'm really looking forward to participating in this one... once i finish other contests. It seems like I'll have a lot of fun with these alternates once again! Thanks for keeping it up. I like the judging system too.
  • 5 years, 7 months ago JKBrickworks (22K) MOC Designer
    Awesome. Looking forward to seeing what everyone builds!

    • 5 years, 7 months ago plastic.ati (28K) MOC Designer ADMIN
      So do I! There are some points in my pocket to give them to the best ones. - Attila
  • 5 years, 7 months ago colorant (994) MOC Designer
    "The MOC must be a new creation you have designed yourself. " So the new here means could not be the moc submitted a couple months ago while qualify the other criteria?
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