Rot.js tutorial

Ananas aus Caracas: a sample game built using rot.js

Welcome to this tutorial! We are going to create a very simple roguelike game, playable in any modern browser. To achieve this, our language of choice would be JavaScript; to simplify our work, we are going to use the rot.js toolkit.

Requirements

• Basic JavaScript knowledge
• Modern web browser (Firefox, Chrome, Opera, Safari, IE9+)

Notes

Working code samples from this tutorial are hosted at jsfiddle.net and use rot.js from GitHub. Please note that GitHub is not a CDN; you should use your own servers to host all the necessary files.

Setting and contents

The tutorial consists of three chapters, which gradually add more and more functionality. The game itself is pretty simple: motivated by video, a player needs to find an ananas hidden within several boxes in an underground dungeon. It is necessary to find the ananas before Pedro (the ananas owner) finds and punishes you for sneaking into his warehouse.

• Part 1: Graphics

  Start your game right away by setting up the screen, printing the stereotypical @ character and moving it around with the arrow keys.

• Part 2: The object and the map

  This introduces two new concepts: the generic object system that will be the basis for the whole game, and a general map object that you'll use to hold your dungeon.

• Part 3: The dungeon

  Learn how to code up a neat little dungeon generator.

• Part 4: Field-of-view and exploration

  Display the player's field-of-view (FOV) and explore the dungeon gradually (also known as fog-of-war).

• Part 5: Preparing for combat

  Place some orcs and trolls around the dungeon (they won't stay there for long!). Also, deal with blocking objects and game states, which are important before coding the next part.

• Part 6: Going Berserk!

  Stalking monsters, fights, splatter -- need we say more?

• Part 7: The GUI

  A juicy Graphical User Interface with status bars and a colored message log for maximum eye-candy. Also, the infamous "look" command, with a twist: you can use the mouse.

• Part 8: Items and Inventory

  The player gets to collect ("borrow") items from the dungeon and use them, with a neat inventory screen. More items added in the next part.

• Part 9: Spells and ranged combat

  The player's strategic choices increase exponentially as we add a few magic scrolls to the mix. Covers damage and mind spells, as well as ranged combat.

• Part 10: Main menu and saving

  A main menu complete with a background image and the ability to save and load the game.

• Part 11: Dungeon levels and character progression

  Let the player venture deeper into the dungeon and grow stronger, including experience gain, levels and raising stats!

• Part 12: Monster and item progression

  Deeper dungeon levels become increasingly more difficult! Here we create tools for dealing with chances and making them vary with level.