The Ultimate Critical Lego Pieces Guide

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Researchers proved that there are more than 900 million ways to combine just six different types of Lego elements. So, in this guide, I will try to pinpoint these critical Lego pieces you can combine to create different kinds of models.

Moreover, the company releases approximately 130 new Lego sets every year, and a basic Lego set contains 300 pieces, while a set like the Taj Mahal can contain more than 2,000 pieces. Bricks, plates, or baseplates can be found in every set, but each set also has a certain amount of unique pieces.

Determining which Lego pieces are critical is a daunting task as there are thousands of elements that can be used to build models or sets. That’s why I am going to supply you with the information you need to find some of the most common Lego parts.

Types of Lego Pieces


Learning to differentiate between Lego pieces and figuring out the Lego terminology will make it easier to recognize the pieces included in almost every set.

There are approximately ten types of Lego pieces. Each part category includes a wide range of elements in different shapes, sizes, and colors, so here are the most common ones.

Lego Element

You’ll hear this term a lot, even though it doesn’t refer to a specific piece. Lego enthusiasts often use this term while referring to different types of tiles, bricks, or plates.

Plate – Jumper Plate

Lego Plate

A piece that connects two or more elements is called a plate. Its size is usually 1/3 the height of a regular brick. A jumper plate features just one stud that allows a builder to avoid alignments imposed by standard plates. These are some of the most common plate parts.


Lego Brick

This is one of the most fundamental building Lego elements, and you’ll encounter it in every set the company has ever released. The colors and sizes of Lego bricks vary, which is the reason why they have different element IDs and design IDs. Here are several Lego bricks you can use with different sets:


Lego Tile

Pieces that don’t have studs at the top are referred to as tiles. They’re used to create smooth surfaces like floors or building tops. Here are several tile pieces you’ll likely encounter in multiple Lego sets:


Lego Baseplate

A baseplate is the support structure that holds the models you build. It features studs across its entire surface that allow you to connect different elements to it. Here are some of the most common baseplate elements:

Duplo Bricks

Lego Duplo Bricks

Duplo bricks are two times wider, taller, and longer than conventional Lego bricks. They’re designed for children younger than five years old, and they can be combined with standard Lego pieces. The following parts can serve as a replacement for the original Lego Duplo elements:

The Most Common Lego Pieces

Lego Minecraft The Zombie Cave

The easiest way to figure out which pieces are most frequently featured in the brand’s sets is to compare all parts included in sets released in the last few years.

Given the fact that the most basic set comes with 300 pieces and that Lego releases more than a hundred sets every year, you’ll end up with a sample size that includes more than a half-million parts if you consider all sets released in the last five years.

However, it is relatively easy to spot a pattern while analyzing the pieces each set contains, as you’ll notice a huge number of similar plates, tiles, bricks, or jumpers. It’s also worth noting that the list of most common Lego pieces changes as new sets appear on the market.

Here are some of the most popular Lego sets released in the last five years:

Set Compatibility

Some but not all pieces can be used with multiple sets. All Lego sets come with a limited number of pieces that also include several replacement parts you can use if you lose a few pieces from a set. Basic 1×1 or 1×2 bricks and plates are compatible with all Lego sets.

You need to pay attention to the part’s color when combining two different sets since two identical parts may have different colors. Keeping track of all the sets Lego has released over the years is difficult even for the biggest fans.

That’s why each set has a unique number that allows you to identify it quickly and gain access to its part list. Lego also includes the part list in the set’s building instructions section so that users can know how many pieces that set has.

How to Identify a Lego Piece


Each part has a unique four-digit ID that allows you to identify it quickly. Lego pieces also have names that help you determine the category to which the part belongs. The Bricks & Pieces section of Lego’s website contains the tools you need to find replacement parts using their part ID.

Also, the ID is included on the backside of every part, so all you need to do to find out the design number of a particular piece is to look at its bottom.

The company started using design numbers in 1985. These IDs don’t follow a specific order or numbering method, so two completely different parts can have similar design IDs.

The part name also includes the information about the number of studs that piece has. So, a piece that features four studs in a single row will have a 1×4 designation, while a plate or a brick with four studs in two rows carries the 2×4 designation.

Sets With the Same Parts

All Lego sets contain a certain amount of identical parts, as you’ll encounter huge numbers of 2×2 plates or 1×2 bricks in almost every set you can find on the market. Nonetheless, pieces that look almost the same can have different ID numbers.

This happens because Lego sometimes updates pieces by slightly altering their features or changing their colors. That’s why figuring out if a specific part is included in two different sets or not can be a daunting process.

Despite this, certain pieces are included in most sets, and on a five-year sample size, you can find thousands of identical parts in sets released during that period.

In most cases, Lego sets will have the same types of plates, bricks, and baseplates, although pieces such as slopes or jumpers also recur frequently. Lego parts change as more sets hit the market, but basic pieces like 2×4 bricks or 1×4 plates remain a constant in all new releases.

How to Obtain a New Lego Piece

Finding a replacement for a part you lost or damaged shouldn’t take a lot of effort. The easiest way to get a new Lego piece is to order it through the brand’s website, but you may have to wait for ten days or more for the part to be delivered.

Optionally, you can try searching for the piece you want to replace in the official local Lego store or one of the Lego-certified stores in your state. In case the specific part isn’t available in the store, you might still have to wait up to 15 workdays for the part to reach your home.

Numerous online retailers sell individual Lego elements, and purchasing the part you want to replace from an e-commerce store is probably the fastest way to get a new piece. Keep in mind that most web-based retailers don’t have all of the most common Lego pieces.

The Most Important Factors to Consider While Identifying Critical Lego Pieces

Keeping track of Lego pieces isn’t particularly difficult because each set comes with a part list that allows you to know how many individual pieces you have. So finding a replacement for a part you lose shouldn’t take a lot of effort, as long as you know its ID number or the set number.

In case you’re collecting Lego sets, you’ll likely end up with a huge amount of identical pieces, although often in different colors. These pieces are critical for builders because they serve as building blocks for different models.

Here are some of the most important factors that can help you identify critical Lego pieces.

When Was the Set Released?

World Map Set Lego

In 2021, Lego released the World Map set, its largest set yet that contains 11,695 pieces, along with countless others sets. Determining how many pieces sets released in 2021 have in common can take a lot of time, as you’d have to go through lists that contain thousands of parts.

The brand usually removes sets as well as replacement parts for these sets five years after their initial release. That’s why finding a replacement part for a set you purchased a decade ago can be difficult.

Part’s Durability

The vast majority of Lego produced since 1963 are made of acrylonitrile butadiene styrene or ABS plastic. This material is sturdy and very difficult to damage, so most set owners search for part replacements only if they lose the original piece.

All Lego replacement pieces are as durable as the originals, and you can’t damage them easily. The brand recently made its first efforts to shift to environmentally friendly materials, and currently, 80 elements are produced from responsibly sourced polyethylene.


The critical Lego pieces are available in a variety of colors. Some of the parts most commonly included in Lego sets can have more than 50 color variations. Color used to be a part of the piece’s design ID, but the brand abandoned this labeling method in the mid-1990s.

Currently, the part’s name or design ID doesn’t indicate its color, and you’ll have to use the part’s element ID, if available, to find a replacement for an original Lego piece in the same color.

Part’s Availability

Lego’s website grants you access to powerful search tools that enable you to find the part you’re looking for. The Pick a Brick section of the website lets you search for a piece even if you don’t know its set number or part ID.

You can buy individual parts directly from the manufacturer, but keep in mind that Lego’s website doesn’t indicate if a specific part belongs to a set.

Check the Element ID

The element ID contains information about the part’s shape and color. The element ID is only featured on recent sets, so you won’t be able to use it if you are trying to track down a replacement part for a set that was released more than a decade ago.

Unlike design IDs that have four digits, the element ID usually has six or seven digits. You can find the element ID in the set’s building instructions.

How Many Pieces Do You Want to Get?

Finding the replacement for a few missing Lego pieces is often much easier than obtaining hundreds of identical parts you need to complete a creative idea.

Online retailers or local Lego stores keep a limited number of parts in stock, and you should know exactly how many pieces you’re going to need if you’re planning to order a large number of pieces.

The Advantages of Critical Lego Pieces


Extended Versatility

Lego builders who own multiple sets won’t have to look for replacement pieces in case they lose an original part because they can use the same part from another set. In addition, owning multiple critical Lego pieces extends the range of models they can build with elements they have.

Highly Durable

Anyone who ever stepped on a Lego element knows how difficult it is to damage it. Almost all pieces are made from ABS plastic that can withstand high amounts of pressure. Pieces like connectors or brackets are more prone to damage, and they’re not as sturdy as bricks or plates.

Wide Color Variety

Critical Lego pieces are available in a broad spectrum of colors, and a piece with the same designer ID can be featured in multiple sets in different colors. This allows you to combine these parts to create unique models.

Easy to Find

Lego’s design and element ID numbers make finding a specific Lego piece easy. Acquiring either of these IDs doesn’t require a lot of effort, so you won’t have to spend a lot of time searching for a new critical Lego piece.


The individual parts featured in Lego sets don’t cost more than $3. In addition, you can purchase the majority of critical Lego pieces for less than $1.

The Disadvantages of Critical Lego Pieces

Most Parts Aren’t Made of Responsibly Sourced Plastic

Only 80 out of nearly 4,000 Lego elements are made from responsibly sourced plastic. The company announced its plan recently to transition completely to sustainable materials by 2030.

Choking Hazard

Children younger than three years old shouldn’t play with regular Lego pieces because they may attempt to swallow them. Lego recommends Duplo bricks that are larger than regular bricks for toddlers.

Selection Criteria

According to the information released by the company, Lego currently offers more than 3,700 individual pieces.

Such a variety of available parts makes it difficult to pinpoint those that are crucial for every set, as you’re going to need different pieces to build Santa’s Sleigh or the Star Wars-inspired Republic Gunship sets.

I’ve browsed through hundreds of sets and thousands of pieces while trying to determine which Lego pieces are essential. Let’s take a look at the search criteria I used to pinpoint critical Lego pieces.

  • Part’s frequency – I went through part lists of sets produced in the last five years, searching for pieces that are featured in multiple sets. Model’s you’ll find in this article are among the most common pieces you’ll encounter in Lego sets.
  • Color diversity – Most sets contain basic Lego pieces such as a 1×2 brick or 1×1 plate in several colors. I used this parameter to select the most common parts in Lego sets.

28 Critical Lego Pieces

Lego Dots

Even though Lego produces nearly 4,000 different parts, almost a quarter of the brand’s production is allocated to just 12 parts. These parts mostly come from brick, plate, slope, and tile categories. Nonetheless, more than 1,000 pieces appear in more than one set.

I’ve put together the list of critical Lego pieces that are commonly featured in sets the company releases every year, so let’s take a brief look at it.

3023 1×2 Plate

34,615 3023 1×2 plates appear in Lego sets released in the last five years, which makes this part one of the essential pieces you’re going to need to create almost any Lego model. The part appears in 52 color variations.

4073 1×1 Plate Round

No other Lego element is more essential to Lego sets than the 4073 1×1 round plate. There are 38,855 4073 pieces in sets released since 2016. This 1×1 round plate is available in 48 colors.

2780 Technic Pin with Friction Ridges Lengthwise and Center Slots

Although it is not as common as the 3023 and 4073 plates, Lego sets still contain 21,347 2780 technic pins with friction ridges lengthwise and center slots pieces. This part is available in just one color regardless of the set you have.

3710 1×4 Plate

This single-row plate appears 13,556 times in Lego sets that hit the market in the last few years, which makes the 3710 1×4 plates one of the crucial building blocks without which you won’t be able to complete a set. There are currently 36 color variations of this part in Lego sets.

3024 1×1 Plate

It is hard to imagine any Lego set without the 3024 1×1 plates. This basic building block can be used for a wide range of purposes, which is the reason why it was featured 27,101 times in Lego sets in the last five years. This part is available in 47 different colors.

3069b 1×2 Tile

As a perfect addition to a rooftop or a floor, the 3069b 1×2 tile is one of the parts that are commonly featured in Lego sets. While going through the sets, I considered for this article; I encountered this part 14,231 times in 48 colors.

54200 1×1 30-Degree Slope

These so-called cheese parts are very common in Lego sets, as there are 13,098 54200 1×1 30-degree slope pieces in the sets I reviewed. This part offers more color versatility than any other piece, and you’ll encounter it in 52 colors.

3004 1×2 Brick

Although it is counter-intuitive, there are only a handful of brick elements among Lego’s top 12 most common parts. Lego included the 12,848 3004 1×2 bricks in products it released in 2016. This piece is available in 40 colors.

3005 1×1 Brick

The 3005 1×1 brick is the second most common brick part in Lego sets I considered for this article. The company included this part in its sets 11,845 times over the last five years. The 3005 1×1 brick appears in these sets in 50 colors.

3020 2×4 Plate

The 3020 2×4 plate is one of 12 pieces that have been featured more than 10,000 times in Lego sets since 2016. There are 11,391 3020 plates in the sets the company released over the last few years, and the part appears in 39 colors.

98138 1×1 Tile Round

This simple part is an essential component of almost all Lego sets on the market as they contain 25,545 98138 1×1 round tile pieces. There are 53 color variations of this piece.

15573 1×2 Tile Jumper

The sets Lego released in the last five years contain 7,056 15573 1×2 tile jumpers, which makes this part one of the top 20 most common Lego parts. This piece is available in 28 different colors, and you can find it in most online stores that offer Lego pieces.

3005 1×1 Brick

The chances are that you have multiple 3005 1×1 bricks if you purchased one or more Lego sets released in the last few years. Nine thousand two hundred forty-nine pieces in sets Lego released since 2016 have this ID number in the, but they can be hard to distinguish because they’re available in 42 colors.

3666 1×6 Plate

You probably encountered this part, even if you have just a few Lego sets. This 3666 1×6 plate appears 5,891 times in the sets I reviewed. Currently, there are 30 color variations of this part.

25269 Quarter 1×1 Tile

Lego Dots

This part is featured in numerous Lego Dots sets, and it is one of the most common Lego pieces. These sets include 9,236 25269 quarter 1×1 tiles in almost forty colors. Finding the replacement for this part shouldn’t be difficult because all major Lego retailers offer several color versions of this piece.

2412B 1×2 Tile Grille

Lego released the first version of this part in 1990, and since then, it has become one of the key components of the brand’s sets. There are 7,199 2412B 1×2 tile grille pieces in the sets I reviewed for this article. The piece is available in 25 colors but keep in mind that specific color versions of this part can be hard to find.

2420 2×2 Plate Corner

The 2420 2×2 plate corner is by no means a new addition to Lego’s collection of parts because the first version of this piece was released more than three decades ago. Even after all that time, Lego’s sets feature 6,696 2×2 plate corners in 23 colors.

85984 1×2 30-Degree Slope (Double Cheese)

Although it is relatively new, the 85984 1x 30-degree slope appears in more than a thousand sets. I encountered this part 6,738 times in 36 colors while reviewing sets for this article.

15068 2×2 Curved Slope

The first version of the 15068 2×2 curved slope piece appeared in 2014, and since then, this part has been used in almost 1,500 Lego sets. I found 6,456 2×2 curved slopes in 38 colors in the sets Lego released in the last five years.

3021 2×3 Plate

This part has been frequently featured in sets Lego released since 1962. The 3021 2×3 plate was featured in Lego sets I considered for this article 8,205 times in 31 color variations, which makes it one of the top 20 essential Lego pieces.

3795 2×6 Plate

Lego released 3,943 sets that included at least one 3795 2×6 plate since 1978. Five thousand three hundred eighty-two parts with this ID number are included in the sets released in recent years. This 2×6 plate is available in more than thirty colors.

3068b 2×2 Tile

Over the years, Lego featured different color variations of the 3068b 2×2 tiles in 2803 sets, so the chances are that you have multiple versions of this piece if you own one or more sets released since 1972. This part was included 5,313 times in 37 colors in the sample I utilized to determine the critical Lego pieces.

3040 2×1 45-Degree Slope

The 3040 2×1 45-degree slope isn’t among the top 20 most common Lego pieces, but it is still one of the brand’s most iconic pieces. This part was featured in more than 2,500 sets over the last four decades, and it appears 4,347 times in the sets Lego released in the last five years.

99780 1×2 Inverted Bracket

Elements like the 99780 1×2 inverted bracket extend the possibilities builders have at their disposal. That’s is one of the reasons why this piece was included 3,875 times in the sets I considered for this article. There are only 18 color variants of this inverted bracket.

85861 1×1 Round Plate With Open Stud

Even though it appears in less than a thousand sets, the 85861 1×1 round plate with open stud is still one of the essential Lego pieces. I encountered this part 6,278 times while going through the pieces I collected from different sets.

3622 1×3 Brick

It is hardly surprising that I found 4,115 3622 1×3 bricks in my sample because this piece was included in more than 2,000 sets since 1978. You can choose from 31 color versions of this part.

3941 2×2 Round Brick with Axle

This circular brick features four studs arranged around a centrally positioned axle. I found 3,094 individual 3941 2×2 round brick with axle parts in 34 colors in the sets I analyzed.

3034 2×8 Plate

Lego released the first version of the 3034 2×8 plate in 1958, and even after all this time, this part is one of the essential Lego pieces that was included 2,953 times in sets that hit the market since the mid-2010s. I found 31 different color versions of this piece.

Frequently Asked Questions

Question: Do I Have to Buy Each Critical Lego Piece Separately?

Answer: Although buying a single piece is possible, in most cases, you won’t have to do that because all parts you need to build a model are included in a set.

Question: Are Critical Lego Pieces Universal?

Answer: Yes, you can combine critical Lego pieces from different sets to build unique models.

Question: How Much do Critical Lego Pieces Cost?

Answer: You can purchase most 1×1 bricks or plates for less than $1, while an entire set can cost up to $800.

Question: Does Lego Retire Sets?

Answer: Yes, the company releases the list of sets it plans to retire soon almost every year. Lego also discontinues parts occasionally, so you need to check if the piece you’re searching for is still in production.

Final Thoughts

Despite the fact that Lego produces nearly 4,000 different parts, only a handful of pieces are crucial for all of the brand’s sets. Moreover, just 12 parts appear in sets released in the last five years more than 10,000 times.

Finding a replacement for one of the Lego’s critical parts is relatively easy unless the piece is discontinued. Then, you’re going to need part’s designer and element IDs to get an identical piece like the one you’d like to replace.

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