Otrera is an open source role-playing game development system. With Otrera, you can design original table top game engines from scratch, or make new games on top of existing systems.

The software defines an 'Engine' as a set of rules and constructs on top of which games are built. The 'Game' is then the set of content. For example, an Engine might define how classes work with character skills and stats while a specific game would define its own classes and fill in its own values.

The two concepts can be tightly coupled. Otrera users need not create general purpose engines. An engine can include all of the necessary content for a game, making the engine and game effectively one product. This is the ideal approach for people who want to make a unique game with unique rules that are not copied in any other system.

Otrera provides the following tools:

1. Full-fledged engine builder to allow for the creation of original character development and combat systems. Users can then publish, modify, and patent their unique game systems.

2. Character builder and content editing tools. Users can upload spreadsheets to quickly add hundreds of content items.

3. A number of default engines (including Pathfinder) which can serve as the basis of new games and campaigns.

4. A wealth of sample content (classes, skills, equipment, etc.) that can also be copied or adapted.

The goal of Otrera is to help table top RPG and board game makers to create rich, complex, and balanced game systems. Whether you want to make a simple one-off adventure on top of the default engine or whether you want to create a completely original system from scratch - Otrera will let you focus on your ideas and content while handling the difficult mathematical challenges.

Building games with Otrera is easy. Your only limit should be your imagination.