Prepare for FIRST LEGO League Robot Game. The complete guide

This FIRST LEGO League Robot Game guide is the single greatest resource to prepare for the competition. The goal of the guide is to make it easier for every mentor, team, and team member to successfully get up to speed, participate and advance in the FIRST LEGO League competitions. There are over 300+ robots, 1500+ attachments/constructions, 50+ courses, and 500+ tutorials available for rookie teams to start with, for more experienced teams to learn from, and for everybody to have a lot of fun building consistent and reliable robots regardless of their experience and level.

Introduction - Why this guide?

We are mentors, judges, teachers, professional engineers, and software developers with a lot of experience in FLL and we've been helping teams for the last 15 years. At FLLCasts, we share specific courses, robot constructions, attachments, and programs demonstrating how various mission models could be accomplished. Note that we do not share solutions for the current season as this is against our rules, but we share the principles by which different missions could be accomplished and how similar missions were accomplished in the past. You have all the information in one place.

FLL is a journey that is sometimes difficult but always rewarding. You are not alone in this journey. FLLCasts has helped tens of thousands of students build Box Robots, use rubber bands, and program advanced state machines to achieve consistency of the behavior of the robot. We are your partner with all the experience and knowledge that we have, and we will guide you through the process of learning and accomplishing the missions.


That is the current season of the competition, and you are reading this guide because you would like to prepare better for the robot game, have lots of fun, and advance to the next rounds.

The guide will help you with designing and using complex advanced attachments and will also help you with building reliable and consistent robots. But before any of this, you should get familiar with the season, its missions, and rules.

FLL 2023-2024 Rules, Tips, Tricks, and Building instructions

Where to start?

Now that you are familiar with the current season, you can start by moving through a specific course for your LEGO set. You can participate in FLL with any LEGO set, but the four LEGO sets that are most suitable are LEGO Education SPIKE Prime, LEGO Mindstorms Robot Inventor, LEGO Mindstorms EV3, and LEGO Mindstorms NXT.

If you don't have a field from previous years, don't worry, as part of the learning is building alternative models and missions.

LEGO Education SPIKE Prime

Use this course during the season or off the season. What parents and teachers do is ask team members to move through them and approach all the missions and accomplish them. This is the holy trinity of preparing for a competition.

The courses are very suitable for off-season preparation and improving your skills. During the season just move through them fast to watch the tutorials and see what's inside. Use them as a reference to get back to when approaching your problems. There is simply not enough time to submit a solution for the tasks.

LEGO Mindstorms EV3, Robot Inventor, NXT

Both EV3 and NXT are no longer available from LEGO. LEGO does not sell these sets, but almost all of the constructions that were previously built with EV3 and NXT could be reused. After all, they are just LEGO parts with different electronics.

Learn from previous competitions

"Smart people learn from their mistakes. Wise people learn from everywhere they can."

When you prepare for the current FLL season, there is nothing better than having all the experience from participating in previous competitions. But this is not possible, because previous competitions are...well...previous. You are forming the team now. It's a new team, and all the experience from previous years is gone.

Luckily, we've recorded and explained our solutions to the FIRST LEGO League (FLL) challenges since 2012. We advise you to start with the most recent ones and then go to the older missions and their solutions and reviews. Learn how similar missions were approached in the past. As you have this toolbox of knowledge, you can now decide which of the attachments and robots to modify and use for the current season.

Additional Parts you might need

To successfully participate in the FIRST LEGO League competitions, it is good to have a few additional parts. This will allow you to build attachments and robots that can accomplish many more missions. The parts are available on the market (mainly, bricklink) and can be purchased. We've provided a recommended number of parts, but of course, feel free to purchase more or less of the parts.

Additional Parts you might need
FLL Additional Parts

Build a basic robot

There are several options for different robot bases, chassis, and approaches. These robots are suitable for starting initially and getting going with the competition. Based on the review you've done of previous competitions, you have to make a choice, and this choice is "Which robot should I build"?

Learn by building several robot constructions, then choose a design that suits your team and your goals. Simple constructions are powerful, and you could easily win a local or regional competition using them. Look at the robots you could build from your LEGO set, but also look at robots that are from different sets, as they have a lot of good ideas in them that you can incorporate.

LEGO Education SPIKE Prime

LEGO Mindstorms Robot Inventor

LEGO Mindstorms EV3

LEGO Mindstorms NXT

Find an answer in 5 minutes

With FLLCasts Tutorials, you can find the answer to your questions in under 5 minutes. All it takes is to find the right "5-minute video tutorial" and watch it. You can find everything from the use of attachments to programming the robot to behave in a specific way.

FLL Tutorials
STEM Tutorial

Advanced Robots

Getting a full run with all the points is difficult to achieve with a basic robot. The reason is the size, the number of motors, the number of sensors, and how easy it is to add attachments. There are a few advanced constructions that can inspire you to build the most perfect robot for your team and your FLL competitions. That is where advanced ideas come into place. Also, don't forget that the more advanced robots would require more parts than the standard set.

Box Robots

Box Robots is the concept of building a robot like a box. In this way, it is easier to attach different attachments as the attachments are standardized - they are all attached similarly. The robots are also balanced and could be quite powerful.

Box Robots for a rookie team could be challenging, but you are participating in FIRST LEGO League after all. :) Challenge is what you are here for. Check out the Box Robot courses first to learn the ideas behind the concepts and implementations. Then build the robots following the building instructions.

X-Y Robots

We call them the "X-Y robots" and the idea is simple - you have one massive attachment at the front that moves left to right on the X axis up to down on the Y axis. Technically, it is possible to accomplish many missions with these attachments.

These are advanced robots. Be aware. They provide sharp knives, and you can cut yourself. The other thing about these robots is that one such robot almost ruined the season when they were officially introduced, as almost everybody was jumping on building such a robot for the competition.


Learn to build attachments. Rubber Bands, Gears, you name it. Do not over-engineer. Use as few parts as possible. Build simple pinless attachments that could be changed quickly. An attachment should work 9 out of 10 times. Use rubber bands, gear wheels, worm gears, racks, levers.

Do not focus on the set here. FIRST LEGO League allows you to use almost all LEGO parts (check with organizers of your local competition if parts are forbidden). That means you can explore attachments with EV3, NXT, Technic, Robot Inventor, SPIKE Prime - practically all the different LEGO sets. You can learn, be inspired and inspire team members. You could also easily purchase some additional parts on the Internet - try Bricklink.

Program a robot

You can not prepare for competition without learning how to use the sensors. Learn to use them, follow lines, position yourself on the field with the Color/Light sensors, detect your rotations with the Gyro, and use State machines to separate the states in your program.

What you should be looking for is how to reliably and consistently position on the field, starting from the base.

LEGO Education SPIKE Prime

LEGO Education SPIKE Prime is programmed with Scratch and with Python. The Scratch version could be downloaded to your computer, or you could use the online version at SPIKE LEGO Education website

Scratch is easier to start with and it is not less powerful than Python.

LEGO Mindstorms Robot Inventor

LEGO Mindstorms Robot Inventor is programmed with Scratch and with Python. The Scratch version could be downloaded to your computer, or you could use the online version at SPIKE LEGO Education website

Scratch is easier to start with and it is not less powerful than Python.

LEGO Mindstorms EV3

You will surely get tired of all the differences in the venues and their lighting conditions. Winning teams have the sensors properly calibrated and could calibrate them very fast, just before the runs.

Mindstorms robots are programmed with a LEGO Mindstorms EV3-G software, which is already deprecated. But you can also use Scratch to program them.

LEGO Mindstorms NXT

Mindstorms NXTs are programmed with NXT-G.

Advanced programming

Learn more about advanced programming like moving straight and state machines. This is the most common problem at competitions. How do you move straight? Or at least Straighterrrr?

Consistent and reliable robots

We try to build robots that can accomplish the missions 10 out of 10 times. Building and programming a reusable and consistent robot is the single greatest thing you could learn. Look at the different examples of "10 out of 10" tutorials.

Tips and Tricks from previous seasons

We publish tips and tricks at the start of every season. We share what you could look at and learn from. Make sure you see these materials as they gather all the resources for the seasons with all the rules, building instructions, and the specific tips and tricks on how to accomplish a mission.

FIRST LEGO League (FLL) 2022 Super Powered

Review, building instructions and tips and tricks for the season

FLL 2022 Review, Rules, Tips, Tricks, and Building instructions
FLL 2022 Super Powered

FIRST LEGO League (FLL) 2021 Cargo Connect

Review, building instructions and tips and tricks for the season

FLL 2021 Review, Rules, Tips, Tricks, and Building instructions
FLL 2021 Cargo Connect


Review, building instructions and tips and tricks for the season

FLL 2020 Review, Rules, Tips, Tricks, and Building instructions

FIRST LEGO League (FLL) 2019 City Shaper

Review, building instructions and tips and tricks for the season

FLL 2019 Review, Rules, Tips, Tricks, and Building instructions
FLL 2019 City Shaper

FIRST LEGO League (FLL) 2018 Into Orbit

Review, building instructions and tips and tricks for the season

FLL 2018 Review, Rules, Tips, Tricks, and Building instructions
FLL 2018 Into Orbit

Finally, explore further

At we have many resources on a lot of different topics connected with FIRST LEGO League and other robotics competitions. Make sure to check for new Tutorials and Building Instructions

All reviews from 2012 to current day

These are reviews not only for FIRST LEGO League, but also for World Robot Olympiad. Check them out. You might find interesting attachments and programs on which to base you current approaches to the competition.


FLL Casts has great content! Our team is composed of 4th-5th grade students and we found the information you provided on topics like Box robots *extremely* helpful. Also, the tips on how to follow a line and other types of intelligent robot control are invaluable. There is no resource like FLL Casts out there for a new team of young kids who are eager and excited to learn the EV3. Neither Lego nor First Lego League provides *any* step-by-step instruction from both a mechanical and programming point of view - which seems like a huge miss.

Dave Covino

February 2021
I want to thank you for your programs, they were so valuable in having a FLL team move forward.

Jerome Seppelt

January 2021
First of all, you have produced a page with very nice content. Thank you very much. Since I participated in the FLL contest, I was using your web page in robot design and basically to learn the codes. I chose not to participate in the competition this year. I am thinking of rejoining your platform when I decide to join the competition again.


November 2020

See all Testimonials.

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