KT-Robots Programming Challenge

KT-Robots is a port of the λ-Robots Team Hackathon challenge

The original idea can be traced back to the 70s game RobotWar.

This repository is an implementation of the game in the kotlin programming language and the spring framework.

KT-Robots is a Team Hakcathon programming challenge build using serverless technologies. You can get access to the code on GitHub

In KT-Robots, you program a battle robot that participates in a square game field. Each turn, the server invokes your robot’s Lambda function to get its action until the robot wins or is destroyed.

Level 0: Setup

Install the required tools

Make sure that you have the following tools installed on your computer.

Setup AWS Account and CLI

The challenge requires an AWS account. AWS provides a Free Tier, which is sufficient for the challenge.


For this challenge we will be using the US-EAST-1 region

Clone Git Challenge Repository

Run the following command to clone the KT-Robots challenge.

git clone git@github.com:onema/kt-robots.git
cd kt-robots

Level 1: Deploy functions and server

Deploy using Cloud Formation and The Serverless Framework

From the command line use gradlew to run the deploy-robots task:

./gradlew deploy-robots

This task will

  • Compile the lambda-robots project
  • Deploy the Lambda functions to your AWS account in the us-east-1 region using the serverless framework

Or use the IntelliJ Gradle plugin to execute the task.


Once the command has finished running, the output shows you the ARN of the lambda robots.

  BringYourOwnRobot: kotlin-robots-dev-BringYourOwnRobot
  YosemiteSam: kotlin-robots-dev-YosemiteSam
  HotShot: kotlin-robots-dev-HotShot
  RoboDog: kotlin-robots-dev-RoboDog
  TargetRobot: kotlin-robots-dev-TargetRobot

The BringYourOwnRobot is the robot you will be working on!


Open lambda-robots/src/main/kotlin/io.onema.ktrobots.lambda/functions/BringYourOwnRobot and customize the field NAME of your robot to distinguish it from other robots.

Deploy the game server using CloudFormation

From the command line use gradlew to run the deploy-server task:

./gradlew deploy-server

This task performs the following actions:

  • Compile the server
  • Deploy the game server to your AWS account in the us-east-1 region using CloudFormation
  • Creates a docker image that runs the server
  • Create an ECR docker repository to host the image
  • Pushes the image to the new docker repository
  • Creates a Fargate cluster
  • Creates a service and runs a task exposing port 80

Once the deployment has finished, you have to log in to AWS to get the server IP:

  • Amazon ECS
  • Clusters
  • ktrobots-server-cluster
  • Tasks
  • Select the task from the list
  • Copy the Public IP
  • You can also expand the task details and get a link to the CloudWatch logs

Once you have the IP paste it in your browser.

# For example

You can add the robot lambda function ARN to the game board client in the browser. You can add the ARN multiple times.

Game configuration

Use the Advance Configuration to change any default settings. Use Clear Saved Config to reset all settings to default.

Level 2: Select Robot Build

The default server settings allow each robot to have 8 build points. You can spend your points in the following equipment:

Equipment type Description
engine Modify your robots speed and acceleration
armor Protect your robot against missile and collision damage. Heavier armor will affect your speed and acceleration
missile Missiles your robot can shoot. These have different velocity, damage points, ranges, blast radius and reload times
radar Allow your robot to detect enemies for a given distance and angle of view

To customize your robot build, open the BringYourOwnRobot function and update the values in the LambdaRobotBuild method. For additional details on the different equipment types see the Robot Build section in the Programming Reference.


If you go over the allotted number of points, your robot will be immediately disqualified

Level 3: Create an Attack Strategy


Develop (or Copy) an Attack Strategy

Now that you have deployed all the robots to your account add the ARN of the TargetRobot multiple times to the KT-Robots server to create targets.

Update the behavior of BringYourOwnRobot to shoot down the target robots.

Use Luck - YosemiteSam

For example, you can use luck, like YosemiteSam, which shoots in random directions.

Yosemite Sam

Yosemite Sam is fast and trigger happy!

This robot chooses a random angle on every turn and fires a missile. It has an extra-large engine that helps avoid attacks and keeps its distance from the edges of the game board to avoid collisions!

Equipment Type Points Details
Armor Light 1
Engine Extra Large 4
Radar Ultra Short Range 0
Missile Dart 0
Total 5

Use Targeting - HotShot

This robot uses the scan() method to find enemies and aim missiles at them.


HotShot is patient and accurate; it hardly ever misses its target!

This robot uses the scan() method to find targets. If it doesn’t find targets, it moves to a new location. If it receives damage, it initiates an evasive move.

Equipment Type Points Details
Armor Medium 2
Engine Large 3
Radar Short Range 1
Missile Javelin 2
Total 8

Chase like a dog - RoboDog

This robot uses the scan() method to find enemies and chases them causing collision damage.


RoboDog moves at random and scans what is right in front of it. When this dog bites, it won’t let go!

This robot uses the scan() method to find targets right in from of it. If it does it adjust it’s heading to move towards the target, this dog can hit you with a missile and with collision damage!

Equipment Type Points Details
Armor Light 2
Engine Standard 3
Radar Ultra Short Range 0
Missile Cannon 3
Total 8


This robot just sits down and waits to be hit. TargetRobot

Please don’t be the target robot, and nobody wants to be the target robot!

Equipment Type Points Details
Armor Heavy 3
Engine Economy 0
Radar Ultra Short Range 0
Missile Dart 0
Total 3

Remember that

  • Other robots may be out of radar range, requiring your robot to move periodically.
  • Your robot can be damaged by its own missiles.
  • Check gameInfo.farHitRange to make sure your target is beyond the damage range.
  • If you don’t mind a bit of self-inflicted pain, you can also use gameInfo.nearHitRange or even game.directHitRange instead.

Level 4: Create an Evasion Strategy


Add the YosemiteSam ARN twice to the KT-Robots server to create two attackers.

Now update the behavior of BringYourOwnRobot to avoid getting shot.

You can be in continuous motion, like YosemiteSam, which zig-zags across the board, react to damage like HotShot, or chase and ram into your opponents like RoboDog.

Beware that a robot cannot change heading without suddenly stopping if its speed exceeds Robot.MaxSpeed.

Level 5: Take on the Champ

take on the champ

Add the HotShot ARN once to the KT-Robots server to create one formidable opponent.

Consider tuning one more time your robots build by updating the equipment

  • engine
  • armor
  • missile
  • radar
🎯Set the proper equipment to suit your attack and evasion strategies.
⚠️Remember that your build cannot exceed 8 points or your robot will be disqualified from the competition.

BOSS LEVEL: Enter the Multi-Team Deathmatch Competition

death match


For the boss level, your opponent is every other team! Submit your robot ARN and see how well it fares.

May the odds be ever in your favor!


The ECS Fargate task run on spot instances and this is the cost for running the server:

  • 512 vCPU $0.00639685 per hour
  • 1024 MiB $0.00140484 per hour

While it will cost you cents to run this task for a few hours, you want to turn it off after you are done with the challenge. Use the following commands to destroy all the resources:

./gradlew delete-robots
./gradlew delete-server