Book IV - Chapter 1, Challenge 1: Round, Round, get a Round... Tower

[Grover]

Book IV - Chapter 1, Challenge 1: Round, Round, get a Round... Tower

With the opening of the first University of Petrea satellite campus in Avalonia came the first guest expert lecture promised by the crown. Since the campus buildings were not yet finished, the classes were meeting in various halls and rooms across Albion, but the lecture was well attended. This expert was an engineer and architect who had designed numerous castles across Historica and came to share insights gained through the years. In particular, construction of round towers, particularly when used as flanking towers in a fortified structure, provided strategic advantage to the defenders. These structures were not as straightforward to build as square towers, so their construction was a point of interest.

Technique

This challenge will teach how to build a curved, load bearing, SNOT wall capable of producing inner, outer, or non-uniform surfaces by using sticks-on-track systems. The rules and criteria are presented at the top for ease of finding them. The technique instructions follow.

 

Category A: Building a Round Object from.... a Square Block? 

The University of Petrea at Albion campus is new and under construction, but there are many aspects of University life.  There are University buildings, classrooms, workshops, dormitories, areas where outdoor field classes are taught on subjects like forestry, geology, botany, etc, and the Avalonian countryside is rich with not only towers and castles but cliffs, rolling hills, farms, demihuman communities, magical creatures, areas of wondrous natural beauty... the imagination runs wild.

Your task: Build a depiction of some aspect of the University in the new Avalonian satellite campus using the new curved wall technique.  This can be a building, but could also be any aspect of University life: a classroom, games, social events, construction of the new campus, research being conducted by professors and students (magical and/or mundane), etc.. The curved wall can of course be a classic wall like a tower, a serpentine wall, or an interior wall of a round room, but it can also be used to make trees, curved cliff faces, and other designs. The nature of the University related build is up to you, but you must meet these 4 requirements:

1. The build must be in Avalonia.
2. The build must depict some part of the new Avalonian satellite campus or University life there. Your sigfig in his Avalonian hometown mailing a letter to a student on campus or a conversation of far off bards talking about the new campus won't work: the idea is to develop the Avalonian satellite campus through building some part of the new campus with collaborative story here.
3. The new curved wall technique must be used in some significant portion of the build. It does not have to be all of the build or even the main focus of the build, but its implementation must be obvious and non trivial. It could be used to make a bunch of tree trunks for a massive forest in the background, a cliffside, a serpentine retaining wall on the campus quadrangle, etc., but having some tiny 3 stud wide corner of a room that is insignificant to the build defeats the purpose of this challenge. If you have questions, ask in this thread or PM me.
4. A work in progress (WIP) shot must be shown at or before the halfway point (1 May 2026) in your entry thread post (see Miscellaneous below).

Maximum size: Unlimited. Multiple builds are allowed to be combined to tell a story or show interwoven scenes, etc.

Miscellaneous: This follows the general judging rubric with one additional stage gate requirement: This is a 4 month build with a 2 month stage gate: You MUST post a WIP shot on or before the 8 week mark (halfway point, that is to say 1 May 2026) that shows your use of the new technique. You don't have to show the entire build if you don't want but you must show the portion that uses technique in progress. Your WIP pictures will be commented on in the forums to help you improve the technique.  These comments will be posted as soon as possible, hopefully within 2 weeks of the WIP shot (I say hopefully because if we get overwhelming response I may have to increase this, but 2 weeks should be enough).  Because this is a teaching build, there are no points awarded for the quality at this stage (so don't worry if you are struggling, post what you have), but you MUST show the WIP (go/no go) in order to be eligible for the final prize at the end. You may show more than one WIP for extra feedback as long as one is on or before the 8 week deadline, but if you post an extra one within a week of the FINAL deadline (1 July 2026), it may not be commented on in time.  Please create your final entry thread and post the WIP shot in there for comment, then post your final entry in this same thread afterword.

Additionally, because this build is required to be in Avalonia and related to the University satellite campus, you cannot claim any of the Category A builds for HSS.

Prizes:

The entries with the highest two scores in Category A will win (respectively):

• 1st Place - 11373 Sauron's Helmet
• 2nd Place - 71829 Lloyd's Green Forest Dragon

 

Category B: O, Romeo, Romeo... wherefrom art thou?

The Queen has taken a keen interest in someone from outside Historica. 

Your Task:  You must provide some background for Zîrâd, the merchant that the Queen has taken an interest in.  What is his family background? What is his home country and/or hometown like? What is his family's business? Why and/or how is his home country's government oppressive?  Does he have any interesting history? What events brought him to Historica and how did he get here?  If you need inspiration, take a look back to between Book II and III at the Safe Haven challenge and its entry thread.

This smaller build must also use the curved wall technique taught above but can take place anywhere.  A WIP shot of the technique in question is not required for this category, but encouraged, and will enjoy comments for build improvement.

Maximum size: 256 contiguous studs area with reasonable overhang.

Miscellaneous: The winner's story isn't necessarily exclusive canon, since other suggested storylines could be complimentary or combined, but the winner's story is guaranteed to be included.

Prize:

The entry with the highest score in Category B will win: 40478 Mini Disney castle

 

DEADLINE

Both Categories: 1 July 2026 (anywhere in the world).  Once it is no longer 1 July 2026 anywhere in the world, the challenge is closed. The WIP deadline for the Category A halfway point stage gate is 1 May 2026, anywhere in the world.

 

General Rules

• One entry per category per person
• No clone brands (Megablocks, KREO, etc) allowed, but 3rd party (or your own custom waterslide decals, prints etc.) fig parts and accessories (Brickarms, Citizen Brick, etc.) are acceptable.
• Custom non-Lego elements similar to what Lego provides (cloth capes and sails, string etc.) are allowed.
• The same person cannot win both categories, although you can enter both.
• Guild leadership is ineligible for prizes (since leadership judges the entries!).
• This contest is open to all members of the Guilds of Historica who have posted a picture of their sigfig and declared for a guild before the halfway point (1 May 2026) 
• Your Eurobricks account must have been created prior to 1 March 2026.
• All entries should be posted in their own topic, with the title of: "Book IV Prelude Challenge: Category X: Name of your build".  Please also post a link to your topic here.
• Prizes may be substituted with Lego gift cards of an equivalent value if postage is exorbitant.

Post questions in the thread below and they will be answered: here for rules questions, below under the technique section for questions on the technique.

Questions

Q: Does my sigfig have to appear in this build?

A: No.  If you want to include your sigfig or others, go ahead. If not, there is no requirement.

Q: Is this contest open to all Guild members, not just Avalonia?

A: YES!  This challenge is set in Avalonia, and we are planning one challenge per guild setting (plus a few others not guild specific) so you get to build in all the guilds if you participate in all the challenges.

 

Curved Wall Technique

For years I wanted to make good looking round towers and had tried one technique after another. Some looked good but were fragile, some sturdy but looked bad, and others used rare parts making them cost prohibitive.  Eventually, I found a technique and modified it, the optimization of which is the class below.

 

The idea behind this curved wall came from someone in Innovalug, whose page I can no longer access, so sadly I cannot link to the original.  It was posted prior to the release of the 1x2 round plates, and was achieved primarily with 2x2 tiles.  I wish I could point everyone to it, so if anyone knows the originator, PM me and I'll try and get links to their work.  The genius behind this technique is that it utilizes standard Lego distances: The thickness of a brick being equal to the distance from the top of a stud on a plate to the bottom of a plate connected to it one brick above (see picture below for this to make sense). In this way, a flexible, movable, friction-fit SNOT connection is made.  I modified this technique to use 1x2 tiles and plates, expanded size, applied it to interior curves, built levels and various openings for windows and doors, and modified it for the 1x2 rounded plates when they became available, which enhanced stability and ease of sliding the components around.

 

 

With this in mind for an idea of where we are going, let's take a look at the components.

 

The Basics

 

The most basic form of this technique is to hold a SNOT 'stick' between two flexible tracks. Multiple sticks can form a wall and closing the tracks can make a ring that can be turned into a cylinder, but the most basic is just the sticks and tracks.

 

The Track

 

The track is 5 plates tall. Technically, 4 plates and one tile since you need a flat top.  Depending on your collection, this can be achieved in multiple ways.  The most basic is a layer of 1x1 round plates and 1x2 plates, followed by an overlapping layer of 1x1 cylinders and 1x2 bricks, followed by a final overlapping layer of 1x1 round tiles and 1x2 tiles. I use coordinated colors below for illustration, but since this won't be seen, you can use a rainbow of whatever you have (see update below just before the examples). When I make a long track, I tend to do portions assembly line style.

 

 

+ The advantages to this are that no special pieces are needed and any color combination can be used since it is hidden in the finished product. That being said, I try to avoid super bright colors (the new fluorescent yellow and the oranges come to mind) since they have the best chance to show through with bright lighting if there is an unintended crack or deviation in the build. 

 

- The disadvantages are that this track is a little more fragile, and thus a bit more difficult to move sticks around on since the corners of the 1x2 bricks and plates are not rounded.  That being said, once the sticks are set the build has the same rigidity, so if you don't have the rounded plates at your disposal and are patient, this will work for you and most Lego collections have these common elements.  If you don't have access to the round plates and still need more rigidity than the brick and plate track can afford, you can also use alternating 1x2 plates and 1x1 round plates to achieve a strong connection. This of course uses more parts and thus becomes more expensive however.

 

The advent of the 1x2 round plate in 2018 (35480) improved the stability and ease of this technique. In this case, 1x2 round plates are stacked in 4 overlapping layers followed by a layer of round tiles (either 1x1 or 1x2 round tiles).

 

 

+ The advantages here are strength and the ease of moving sticks along it due to rounded corners. These are easy to use because they do not fall apart with abuse as easily as the brick tracks do when free (the brick tracks are just fine once seated in sticks).  These will be used for the remainder of the example builds, but you can substitute the brick tracks if you need to in any of the examples. See the end of the instructions just above the examples for pictures of the brick and plate tracks in use.

 

- The major disadvantage, which seems to be obvious, is cost.  Not only are the 1x2 round plates $0.07 each from Lego PAB, you need more of them than the bricks and plates since there's 4 layers.  I was both excited and dismayed when I first saw these plates, knowing they would improve this technique and that I could not afford them.  Happily, these plates appeared shortly after on the PAB wall at my local Lego store, and because they are hidden in this technique, their color does not matter.  Usually BL sellers have these for reasonable prices in quantity since they have appeared on PAB walls.

 

The Stick

 

The other component of this technique is the stick.  These are straightforward to build and made from common parts, but are numerous, and if you are after a uniform surface, will need a lot of uniform pieces for the outer shell.

 

The basic stick needs a layer of plates followed by a layer of bricks followed by a layer of plates, and an outer decorative shell.  Axially, the stick has two ends that are two studs wide that fit onto the track, and a center that is as  short as one stud and as long as you wish.

 

 

Practically speaking, I find that the plates need at least two studs of brick to 'bite' onto it or they are fiddly and fall off frequently. Ideally you would use a single plate if you have a short distance run in a size of which plates are made (say 8, 10, or 12 studs) but you can make due with 1x4 plates at a minimum.

 

The theory behind the end of the plates where they attach to the track is on a vertical level, the two stud SNOT plates are equivalent to 5 stacked plates horizontally, and the horizontal SNOT distance from the top of the stud to the back of the plate above is equal to the width of a brick as illustrated in the background section.

 

The decorative shell can be horizontal interwoven tiles to represent bricks, vertical plates to represent organic matter, random plates and bricks to approximate geological formations or anything you can imagine, which we will see examples of later.

 

The Technique

 

To create a curved wall or surface with this technique, you need multiple sticks that are held on two tracks.  First, we will build 5 sticks, each 8 studs long, which means we will need two 1x8 plates and one 1x4 brick of any color for each stick.

 

 

For the tracks, we will use 1x2 round plates and 1x1 round tiles, again any color, but we will need six 1x2 round plates per row and 4 rows (24 per track), plus twelve 1x1 tiles per track.  Make 2 tracks like this, or, if you are using the brick track, with bricks and plates etc. For my own convenience (and because I have several lengths of this assembled already) the remainder of this tutorial will use the rounded plate track, but you can substitute the brick/plate track wherever you see this rounded plate track.

 

 

Flatten both tracks on the table, then pick one and stand it studs up on the table. To this, add the sticks, SNOT, studs all forward

 

 

Now gently work the top track onto the top of the sticks. For short runs like this, it's not too bad, but be prepared to be patient and do a lot of gentle wiggling for large rings or irregularly curved surfaces.

 

 

You can bend this track how you like now.

 

 

You can also decorate the studs with alternating uniform tiles to make it look like stonework, muddy cliffs, large bricks, whatever you want. Helpful tip: If you have long sticks or large towers, lining up alternating tiles prior to connecting the plates to the brick can help.

 

 

The sticks can be spaced to allow for an interior or exterior curve.

 

 

Alternately, if you would rather have somewhat irregular studs showing, you can add wedge plates, tiles, etc. along the axis for details such as tree bark.

 

 

The sky is the limit with the details here.  This technique really shines when you need a lot of detail. Round towers built out of bricks such as castles or round turrets on structures look great.  Modern smooth steel pieces like chemical tanks or water towers tend to look pixellated. Any organic materials like trees do well.  

 

Options

 

If you wish to make a circular tower, you only need close the tracks into equal size rings. (I tend to mark every 10 studs with an off color tile so I can keep track of the circumference).

 

 

Then add enough sticks to close gaps around. Closing the gaps on a completely circular tower can be a bit fiddly, and there are some circumferences that are cleaner than others, but you can usually get very close if you play with it a bit.

 

 

If you want to add a window or a door, you can remove a few sticks, leaving a gap.  Then you can build on the space between the rings. You can even attach to a ring by adding a stud to your window or door frame (see the green tower below in examples for a finished window).  Directly below, you can see the opening left by removing sticks, plus a cutaway of how the sticks work with some decorative outer layer removed.

 

 

How do you cover the section of the lower ring track that you can't attach to the top ring since there is an opening? You can add an extension from a lower layer, seen here sticking up from the top track.  You can also see optional changes to the sticks, such as adding a batter to the base of a castle tower (here partially done so you can see the difference).

 

 

Note the lone stud on the top ring track. It allows a second tower section to attach to the top. These sections line up for seamless integration, and the extension from the lower level covers the missing stick area above.

 

 

The beauty of the technique is that the structure is load bearing because the SNOT bricks that form the center of the sticks sit between the two tracks and are solid, so they support tremendous weight and you can easily use these as building platforms for large, tall structures.

 

 

One limiting aspect of this technique is curvature. This technique is great for big curves. It does pretty well with surprisingly tight curves, but once you get into really small cylinders or curves, it has difficulties and can appear blocky. Down to a certain size, you can substitute the 1x2 curved smooth slopes (11477), but there is a limit to minimum diameter due to the thickness of the track and sticks. Fortunately, there are macaroni bricks of this diameter and larger that avoid the need for this technique.

 

This is one of the most versatile techniques I have found, and I hope that you all enjoy it as much as I have.

 

Update 2 March 2026

 

After some questions, I hope I have not given the wrong idea that only the round plates can be used. I went back and rephrased some of my sentences to make sure that was not implied.  In fact, to prove there is no issue with using the brick method (and thus what you have in your collection more affordably, I give you the "trash tracks" made of whatever I randomly pulled out of my loose bins.

 

 

And onto those go not entirely uniform tiles, but a mixture of a color scheme that you might have laying about your collection.

 

 

I did a poor job consolidating the sticks there because I was in a rush and you can clearly see light through them, but I did a better job on the interior curve.

 

 

As you can see, the exterior of the wall looks just fine and hides whatever is behind it, so please don't think that I'm advocating for you to go spend a lot of money on the 1x2 round plates!  If that's what you really want to do or you find them at your local PAB wall, then have fun, but the purpose of this technique is to show you that you can use it with bricks that have been around for a long time. I think the latest piece to release was the 1x1 round tile that released in 2011, and this is fortunately found many places cheaply and usually comes as extras in most sets.

 

Examples

 

I have included a few examples from my previous builds, some of which may escaped notice.  I consider that a good thing if they have, since it means they have blended seamlessly into the build.

Small, tight curve between straight walls, incorporating an opening for a door and 1x2 curved slopes in places to achieve smoother texture.  This is in fact made with the brick/plate track and not the rounded plate track since it was before I had a ton of the rounded plates.

 

 

Lovely sand green color, complete with overhanging battlements, window, and attachment to straight wall.

 

 

Tower under construction with both inner and outer curvatures: there are actually TWO concentric towers here! The top layer where the mason is working is attached to the top ring and is for show.

 

 

A subtle inner curvature with door and window openings, and tiled doorframe by extending the sticks out with an extra plate before tiling.

Spoiler

At last!  This challenge has been some time in the making. It's been fun, but also has been a lot of work in the setup.  It's also somewhat of a departure from our normal challenges, in that it is a technique-based build and it teaches the technique in its execution. I am very interested to see everyone's creativity when it comes to implementing the technique, and I am excited to see the directions that the storyline heads as everyone builds their own stories and ideas for the two challenges. We hope you all enjoy!

 

[Velnerius]

I really like the idea of this type of 'learning challenge'! 

 

I was familiar with some techniques for round towers, but not with this exact one, and it looks very interesting to play around with! I hope to have the time (and pieces) to come up with something.

 

Am I correct in assuming that it won't be necessary for our sigfigs to appear here (as mine has other business back in Varlyrio to attend to!), and that members from all guilds are welcome to join, as long as the build itself is in Avalonia?

[Grover]

6 hours ago, Velnerius said:

I really like the idea of this type of 'learning challenge'! 

Awesome!  I hope everyone is as excited!

6 hours ago, Velnerius said:

I was familiar with some techniques for round towers, but not with this exact one, and it looks very interesting to play around with! I hope to have the time (and pieces) to come up with something.

I look forward to seeing the creativity you and others have for using this technique.

6 hours ago, Velnerius said:

Am I correct in assuming that it won't be necessary for our sigfigs to appear here (as mine has other business back in Varlyrio to attend to!), and that members from all guilds are welcome to join, as long as the build itself is in Avalonia?

Correct. Your sigfig is unrelated to this challenge (although they or anyone else's can show if you feel like it).  And absolutely, this is a GLOBAL CHALLENGE OPEN TO ALL GUILDS OF HISTORICA MEMBERS!  I put that in caps so it will catch the eye of anyone reading.

We have one 'learning' challenge like this planned in each Guild, assuming people don't hate it (in which case we will scrap it and revise) but the idea is that each challenge will teach 1 technique and will cause members to build in that particular guild, so by the time we are done, everyone will have 5 new techniques and have built in each guild if you have done all the challenges!

[Seagull King of Vaughan]

This is lovely to hear. My building technique is still firmly in the mid-2010’s, when I last did large-scale MOC work. I’ve never built a round tower before; very eager to steal this method!

I suppose the main issue will be the cost of all the track bricks… I needed a good excuse to stop putting off my latest Pick-A-Brick order anyway.

[Grover]

5 hours ago, Seagull King of Vaughan said:

This is lovely to hear. My building technique is still firmly in the mid-2010’s, when I last did large-scale MOC work. I’ve never built a round tower before; very eager to steal this method!

I suppose the main issue will be the cost of all the track bricks… I needed a good excuse to stop putting off my latest Pick-A-Brick order anyway.

I hope you enjoy the technique!

This should not break the bank since you don't have to get the round plates. You should be able to use normal bricks, plates and tiles for the track, and it can be rainbow colors, use palisade or technic 1x2, etc. It is what I used initally and is used in the brewery build before I had ample round plates. Of course, once my local store had some on the PAB wall, it became very affordable. BL may have some in random color that others got off a PAB wall too. Additionally, you don't need a giant curved section. That oven in my brewery build is substantial and a focus of the build but not huge.

Mostly I mean to say don't get discouraged if you feel you don't have one specific thing or another. There are several substitutions you can make work if need be!

[Grover]

Sorry for the double post, but @Velnerius and @Seagull King of Vaughan, I updated my top post with the instructions to include an example of the non-1x2 rounded tracks so you can see they work just as well.  These are made from common parts so if you don't have access to a lot of the 1x2 rounded plates, you can easily substitute common parts to make these tracks.  Hopefully this helps!

[LordDan]

On 3/1/2026 at 2:42 AM, Grover said:

A work in progress (WIP) shot must be shown at or before the halfway point (1 May 2026) in your entry thread post (see Miscellaneous below).

Miscellaneous: This follows the general judging rubric with one additional stage gate requirement: This is a 4 month build with a 2 month stage gate: You MUST post a WIP shot on or before the 8 week mark (halfway point, that is to say 1 May 2026) that shows your use of the new technique.

 

This challenge looks like a lot of fun, cool to see constrained learning challenges like this! I guess this is one way to force us to start early 

[Henjin_Quilones]

Why have I had The Beach Boys stuck in my head the last few days? “I’m gettin’ bored drivin’ up and down the same old strip, I need to find a new place where the kids are hip…”

[Grover]

On 3/3/2026 at 9:31 AM, LordDan said:

This challenge looks like a lot of fun, cool to see constrained learning challenges like this! I guess this is one way to force us to start early 

Glad to hear it!  And I don't know that we're trying to force you to start 'early' when you have 2 months to show a single picture! 

On 3/3/2026 at 10:32 AM, Henjin_Quilones said:

Why have I had The Beach Boys stuck in my head the last few days? “I’m gettin’ bored drivin’ up and down the same old strip, I need to find a new place where the kids are hip…”

"I'm gettin' bored fastenin' down the same old clip, I need to find a new plate that has more grip..." 

 

 

For all our Guild members: Is Category A too constrained by making you use the technique AND build in Avalonia?  The technique is at the core of the challenge, so that constraint I think is a good creative challenge, but I was a little concerned that it might stifle creativity to make the build in Avalonia.  Knowing the plan was to have one build in each guild this Book, I thought it might be another opportunity for creatively fitting the build into the Avalonian campus.  It's been fairly quiet since the challenge announcement, so if that's excitement or people being busy, that's great, but if there is a lack of interest due to feeling too confined by the Avalonian location requirement, we can remove that since it's early enough in the challenge.  I think we would all love to see creative builds using this technique, and if requiring the build to be in Avalonia is hampering rather than enhancing creativity, I'll be happy to remove it and make the Cat A requirement more open.  If you're happy with it, I'd also like to hear that side too. I won't be offended, we're trying to get this new approach right and make it fun, so let us know one way or the other!

[SimWies]

I really like this style of challenge...from my side it has been a "creative silence" plotting ideas and setting up a PB order 

Also I am looking forward to the other challenges of this type, getting to build in other guilds and learning something new. For my part I think the challenge is perfectly set up! 

Edited Friday at 06:31 AM by SimWies

[The Stad]

I would echo @SimWies and say that this is an exciting prompt.  I think the idea of getting everyone to build in guilds that are not their home guild will be great for builder development and should spur some novel approaches to the respective challenges.  I'm excited to see what other guild challenges will bring in the coming months/years, and I'm very excited by this particular challenge.  I think keeping each challenge as guild-specific is the right move, but only time will tell.

[T-86(swebrickLUG)]

A fun idea for the challenges in each guild. Ive been in to the technical-aspect since it was first mentioned! My guess is people being busy is more likely than a non-interest in the challenge. I need to scrap together my rounded 1*2’s and get going 😃

Edited Friday at 07:29 PM by T-86(swebrickLUG)

[Seagull King of Vaughan]

I second the ‘been busy planning’ comments. I’ve been quiet because of finishing up a freebuild, plus other work, and so probably won’t start on this challenge until the end of the month.

For the geographic confinement of the challenge, I think it works great. For my part, all of my planned freebuilds are Mitgardian (except for one in Nocturnus), so this challenge and others will give me a reason to try some other guild locations out.

I was also able to dig up nearly a hundred 1x2 plate w/ rounded corner parts from my collection, so I can test both methods right away!

[Grover]

@SimWies, @The Stad, @T-86(swebrickLUG), and @Seagull King of Vaughan, thank you for your feedback!  It is a bit challenging when forging into a new space, and since we're short staffed, we don't have as much discussion as we might with a larger group.  I am glad to hear that the location and technique work and aren't suffocating any creativity. I was hopeful everyone was just busy, but since these challenges are for everyone in the Guilds, I wanted to check to make sure we were providing some fun challenges!

Don't let me slow you down further, build away! 

[Ben S]

I’m also on 'team busy' . I’ve been following the Book IV stories and builds and enjoying them a lot. Great work so far! 

As for the challenge, I don't think it's overconstrained, the categories give you a wide range of options. It’s also nice to have a change of scenery for a while.

Regarding your technique, I loved such a detailed tutorial! As you said, it’s really versatile. I remember achieving a similar result by covering the Troll Battle Wheel with 1x2 tiles, but this is definitely more sophisticated!

I don't know if I will have time to submit an entry, but I’ll definitely tinker with that technique!