Belén Albeza wrote this great tutorial on Mozilla Hacks: "In game development there are two methods of rendering text: via bitmap fonts and vector fonts. Bitmap fonts are essentially a sprite sheet image that contains all the characters of a given font. The sprite sheet uses a regular font file (traditionally .ttf). How does this apply to game development on the Web and HTML5 games?
You can use bitmap fonts as usual – they are just images, after all, and most HTML 5 game engines or libraries support them straight away. For vector font rendering, we can rely on any font that is accessible via CSS: this includes both system fonts already present in the player’s computer (like Arial or Times New Roman), or Web Fonts, which can be downloaded on the fly, if they are not already present in the system.
However, not all game engines or frameworks include mechanisms to load these fonts as regular assets –like images or audio files – and rely on them being present already. This can lead to quirks in which the game tries to render a text in a font that is not loaded yet… Instead, the player will get no text, or text rendered with an alternate or default font.
In this article we will explore some techniques for preloading Web Fonts into our games, and describe how to integrate them with a popular 2D game framework: Phaser."