Mozilla is challenging developers to create gaming experiences that push the limits of what Open Web technologies can do.

The idea of this competition is to show what’s possible using the web as an open gaming platform and is looking for games in one of three categories:

1. Hackable Games - Create games that let players remix game mechanics, fork code, or use assets from the web to create their own version
2. Multi-Device Games  - Use the power of mobile to explore concepts like asymmetric gaming, alternate reality games, and companion apps. This category is searching for games that take advantage of the unique affordances of different platforms they inhabit.
3. Web-Only Games - Create games that can only be played on the web. Get inspired by web-only mechanics such as sharing links and data, finding clues on the web that will help you advance in the game, always-on multi-player, and more.

Winners in each of the three categories will receive a Nvidia GeForce GTX690 plus various promotional opportunities and the Grand Prize winner also gets an all expense paid trip to San Francisco with two all-access tickets to GDC 2013, the Indie Game Developer Conference, plusa tour of Mozilla's headquarters in Mountain View,  lunch with the Mozilla games team and dinner with EA's award-winning game developer Michael John. See Prizes for more details.

According to the Rules games must be built using open web technologies. This includes but is not limited to HTML, CSS, JavaScript, WebGL and WebRTC, as well as server-side code like PHP, Python, Ruby or Java. Entries should be playable prototypes, built to run in modern browsers like Firefox, without any plug-ins. They don't have to be fully polished or 100% complete and the judges will mostly be looking for interesting gameplay ideas. 

The competition is open to those aged 13 and over in the US and to those who are the age of majority in other countries - full details in the official rules.

Entries can be made by teams as well as individuals and to get the competition off to a good start there are Game Jams planned for the weekend of December 14-16 in both London and New York City.