Table Of ContentMastering Roblox Coding
The unofficial guide to leveling up your Roblox scripting skills
and building games using Luau programming
Mark Kiepe
BIRMINGHAM—MUMBAI
Mastering Roblox Coding
Copyright © 2022 Packt Publishing
All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, without the prior written permission of the publisher, except in the case
of brief quotations embedded in critical articles or reviews.
Every effort has been made in the preparation of this book to ensure the accuracy of the information
presented. However, the information contained in this book is sold without warranty, either express
or implied. Neither the author, nor Packt Publishing or its dealers and distributors, will be held liable
for any damages caused or alleged to have been caused directly or indirectly by this book.
Packt Publishing has endeavored to provide trademark information about all of the companies and
products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot
guarantee the accuracy of this information.
Group Product Manager: Rohit Rajkumar
Publishing Product Manager: Ashitosh Gupta
Senior Editor: Aamir Ahmed
Senior Content Development Editor: Rakhi Patel
Technical Editor: Shubham Sharma
Copy Editor: Safis Editing
Project Coordinator: Sonam Pandey
Proofreader: Safis Editing
Indexer: Subalakshmi Govindhan
Production Designer: Shankar Kalbhor
Marketing Coordinator: Elizabeth Varghese
First published: August 2022
Production reference: 1290722
Published by Packt Publishing Ltd.
Livery Place
35 Livery Street
Birmingham
B3 2PB, UK.
ISBN 978-1-80181-404-1
www.packt.com
Co n t r i b u t o r s
About the author
Mark Kiepe is an experienced Roblox Programmer and Game Designer with over six years of experience.
He has contributed to several successful Roblox games. Besides these achievements, he is also the
Co-Owner of a Roblox Game Studio called Sarcastic Studios, with games such as Pet Store Tycoon
and Dream Island. Mark has contributed to more than 150 million play sessions across all games at
the time of writing.
Mark started as a self-taught programmer on Roblox. What he learned on Roblox helped him in
college. He currently attends a University of Applied Sciences in The Netherlands, where he studies
Software Development.
I want to thank my parents and brother for their continuous support while
writing this book. I am incredibly grateful for the amount of motivation they
have given me.
Thanks to everyone at Packt for helping me write this book. It means the world
to me.
I want to give a special thanks to Aamir and Rakhi. I have learned so much
about writing through your feedback that I would have never accomplished
without them.
I would also like to thank Vaideeshwari for giving me the opportunity to write
this book.
About the reviewers
Arnav is a UGC Event Organizer working alongside DevRel for Roblox. He has hosted numerous
events on the platform and is also an experienced developer. He has over 350 million contributed
visits. He is known by his Roblox username “AceDevArnav” and is also the owner of Ace Developing
Studios , which is one of the rising studios on Roblox with its upcoming games and UGC items.
Mir Ali was born in Karnataka, India on June 4, 1983. He studied in Dubai, UAE. He learned programming
from the 6th Grade, starting with Q Basics, and then learning C and C++. He found these boring,
as there was no way to visualize the results, and nothing made sense to him back then, except for a
few ways of using IF statements, and a calculator that he made himself. He also couldn’t quite figure
out what the lines of code were, when they started, or what OOP was. He therefore called it quits
on programming and took a journey into building Gaming PC and servers. He then did his Cisco
certification and went deeper to configure ATM relays and protocols, and calculate IP addresses for
big companies.
Years passed by, and he became a father. One day his son came to him and asked, "Father, what is
LUA, and how do you make an obby with rotating parts?" Mir Ali saw hope in his son’s eyes, and got
up, opened Roblox, and started teaching him. He taught his son IF conditions and operators, which
were easy until he reached a syntax “:”, which was from OOP. This was when lightning struck him,
and everything made sense. He taught his son a full library of LUA, including Bitwise operations,
and made his own Physics and network library from scratch. Now, instead of his son, Mir Ali teaches
corporate giants such as Accenture, Vodafone, Microsoft, and Walmart, to name but a few. He teaches
the procedural generation of buildings and environments with complex floors, and ways to enter them.
He also teaches Deep math and trigonometry, such as how to make your own Math library. Last but
not least, Mir Ali teaches M.L and A.I.
To my children, Arafath, Ishan, Hasanath, and Saleyhath, who motivated me.
Table of Contents
Preface
Part 1: Start Programming with Roblox
1
Getting Up to Speed with Roblox and Luau Basics
Technical requirements 3 Lower and upper camel case 16
Understanding Roblox and Luau 4 Updating variables 16
Removing magic numbers 18
Creating an account 4
Introducing constants 19
Introducing Luau 5
Using conditionals 21
Understanding and using data
types in Luau 6 Relational operators 21
if-else conditionals 22
Creating a script 6
Using elseif 24
Hello, world! 7
Nested if statements 25
Numbers 8
Math operations 9 Understanding scopes 28
Combining math operations 10 Exercise 1.1 – Changing properties
String concatenation 11 on a part 30
Escape characters 11
Exercise 1.2 – Police system part I 34
Casting data types 12
Exercise 1.3 – Understanding a script 35
Booleans 13
Summary 37
Logical operators 13
Introducing and using variables 15
vi Table of Contents
2
Writing Better Code
Technical requirements 39 Functions in a table 62
Using functions 40 Programming loops 63
Making a function 41 while loops 63
Parameters and arguments 42 repeat until loops 65
Multiple parameters 44 for loops 66
Default parameter values 45 Continuing and stopping a loop 67
Returning functions 47 Large oops 71
Multiple return values 49
Using modules 72
Nested functions 50
Creating a module script 72
Best practices when using functions 52
Requiring the module from another script 74
Storing data types in tables 53
Exercise 2.1 – simple elevator 75
Storing data in a table 53
Exercise 2.2 – converting loops 75
Reading data from a table 54
Setting data in a table 55 Exercise 2.3 – Police System II
Using dictionaries 57 (difficult) 76
Multi-dimensional tables 58 Summary 78
3
Event-Based Programming
Technical requirements 81 Using bindable functions 96
Introduction to events 82 Comparing events to modules (advanced) 100
Using bindable events in modules (advanced) 100
Functions on instances 82
Listening to events 85 Exercise 3.1 – event-based game 103
Using properties for missing events 88 Summary 106
Creating custom events 92
Using bindable events 92
Table of Contents vii
Part 2: Programming Advanced Systems
4
Securing Your Game
Technical requirements 109 Implementing security 129
Understanding the client and server 110 Server checks 130
Introducing LocalScripts 110 Implementing debounces 131
FilteringEnabled 113 Honeypots 134
Replication exceptions to FilteringEnabled 114 Filtering user text 135
Client and server responsibilities 116
TextObject 136
Using RemoteEvents and The GetNonChatStringForBroadcastAsync
RemoteFunctions 118 function 138
The GetChatForUserAsync function 141
Setting up the GUI 118
Client-sided Team Changer 119 Exercise 4.1: Securing your game 142
Using RemoteEvents 121
Exercise: 142
Using RemoteEvents from the server
Summary 144
to the client 124
Using RemoteFunctions 126
5
Optimizing Your Game
Technical requirements 147 Working with tweens 168
Understanding and using Setting up the gate 168
StreamingEnabled 148 Setting up the server scripts 170
Enabling StreamingEnabled 148 Getting tween data 172
Programming with StreamingEnabled 150 Understanding TweenInfo 173
Creating a tween 174
Working with animations 159
Client-sided debounces 176
Uploading animations 159
Custom yielding functions 178
Understanding the Animator object 160
Exercise 5.1 – greeting an NPC 180
Programming an AnimationTrack 161
Animations on NPCs 164 Exercise 5.2 – falling block 182
Summary 184
viii Table of Contents
6
Creating User Interfaces for All Devices
Technical requirements 185 Working with color-blindness 210
Creating GUIs 186 Displaying controls 211
Improving GUI navigation 212
Using ScreenGuis 186
Using images 213
Using SurfaceGuis 199
Using Tweens 214
Using BillboardGuis 205
Core GUIs 217
Optimizing UIs 208
Exercise 6.1 – Creating a shop GUI 218
Testing GUIs 209
Summary 221
Small UI improvements 210
7
Listening to User Input
Technical requirements 223 Gamepad input 244
Working with ClickDetectors 224 Mouse input 250
Working with ProximityPrompts 231 ContextActionService 255
Working with tools 238 Choosing how to listen to user input 263
Implementing advanced user input 240 Exercise 7.1 – Eating food 265
Keyboard input 241 Summary 269
8
Building Data Stores
Technical requirements 271 Removing data 293
Introduction to data stores 272 Writing safer data stores 295
Saving data 272 Caching data 295
Error handling 275 Autosaving 299
Reading data 276 Improving error handling 300
Creating default player data 278 Data store limitations 302
Saving tables 287 Creating a DataManager 304
Saving dictionaries 290 Setting versus updating data 306
Saving user data in data stores 291
Table of Contents ix
Working with ordered data stores 309 Exercise 8.2 – Simple obby 316
Exercise 8.1 – Building and testing Summary 318
data stores 312
9
Monetizing Your Game
Technical requirements 321 Working with PolicyService 341
Programming game passes 322 Giving Premium Benefits 343
Prompting game passes 323 Implementing Premium Benefits 344
Rewarding game passes 326
Third-party sales 346
Instant game pass reward 329
Implementing third-party sales 348
Implementing developer products 332
Exercise 9.1 – building a currency
Prompting developer products 334
system 350
Rewarding developer products 335
Summary 352
Part 3: Creating Your Own Simulator Game
10
Creating Your Own Simulator Game
Technical requirements 357 Implementing rebirths 377
Introduction to the game 358 Selling orbs 380
Creating data stores 361 Programming GUIs 382
Getting keys for our data stores 361 Programming the SideButtons GUI 383
DataManager functions 363 Programming the Rebirthing GUI 385
DataManager events 364 Programming the DeveloperProducts GUI 387
Programming the GamePasses GUI 389
Implementing server scripts 366
Programming the Upgrade GUI 390
Implementing leader stats 366
Implementing monetization scripts 368 Updating your game 391
Implementing character upgrades 370 Summary 392
Claiming orbs 375
