Mcge NPM | npm.io

MCGE - Multiple Choice Game Engine

An engine to build web-based games or stories where the primary interaction method is a multiple-choice selection.

What is it?

MCGE is a simple engine to build web-based games or stories where the main way the player interacts is using multiple-choice selections. While this is similar to text adventures or visual novels, MCGE aims to provide authors with the ability to easily define custom logic to run in response to player choices, resulting in a complex graph of pages rather than a tree.

It is not intended to have all visual the bells and whistles one could imagine. It intentionally provides few built-in primitives and options to encourage constraint-based design and interactivity via the page choices.

Why?

The design of MCGE is driven by the question:

What sort of games could you make if everything were a page?

A "page" in this context is a single page in the "story book", containing:

some lines of text
(optional) a number of mutually-exclusive choices
(optional) background images
(optional) background music & sound effects

Basic Usage

The MCGE class is the entry point into the engine. Both Javascript and Typescript are supported.

See the following template projects to get up and running quickly:

A basic setup might look like this:

index.html

<body>
  <div id="mcge" style="width: 800px; height: 600px;"></div>
  <!-- This script reference will change depending on your build system and project structure -->
  <script type="module" src="/src/index.ts"></script>
</body>

src/index.ts

import { MCGE } from 'mcge';
import { pages } from './pages';

const game = new MCGE({
  settings: {             // All these settings come with default values, but can be overridden here
    containerEl: "#mcge", // A selector for the element to contain the MCGE game
    content: {            // These percentages are in terms of the container element's dimensions
      height: "40%",
      top: "10%",
    },
    choices: {
      height: "30%",
      top: "60%",
    },
    images: {             // Background images defined within pages will override the default
      defaultBgImage: "https://images.pexels.com/photos/548084/pexels-photo-548084.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
    },
  },
  pages: pages,           // The list of pages defining the story
});

src/pages.ts

import { Page, Utils } from "mcge";

/** Define IDs for pages so they can be easily targetted */
export const PAGE = {
  START: Utils.id,
  BAD: Utils.id,
};

export const pages: Page[] = [
  {
    id: PAGE.START,
    // By default content lines are displayed one after the other
    content: [
      "Howdy! (click to continue)",
      "These lines of content appear one after the other.",
      "What do you think?\n(Click to reveal choices)",
    ],
    choices: [
      // If a next page is not specified, the next page to be displayed is the next in the list of all pages
      { text: "Cool!" },
      // Define a next page in a choice to jump to that page if the choice is clicked
      { text: "I'm not impressed.", next: PAGE.BAD },
    ],
  },
  {
    content: [
      "I'm very glad you like it!",
      "You can make your own story as well!",
    ],
    choices: [
      // Arbitrary functions can be executed in response to selecting a choice
      { text: "OK! Lets go!", onSelect: () => window.location.href = "https://github.com/neon-fish/mcge" },
      // If no next page is specified, the choice uses the page's "next page" definition
      { text: "Not just yet." },
    ],
    next: PAGE.START,
  },
  {
    id: PAGE.BAD,
    content: [
      "I'm sorry to hear that.",
      "Are you sure I can't change your mind?",
    ],
    choices: [
      { "No. I'd rather watch YouTube.", onSelect: () => window.location.href = "https://youtu.be/dQw4w9WgXcQ" },
      { "I prefer Ren'Py.", onSelect: () => window.location.href = "https://www.renpy.org/" },
      // No next page is specified, and the page has no next page either.
      // However, the page list wraps round, so the "next" page after the last page is the first page.
      { "Well, maybe..." },
    ],
  },
];