As in many games, Characters have skills. When using them the Game Master has to know if the character succeeded using this skill. This is the reason to throw against your skill.
SagaS Rules are accessible completely under the Open Game License (OGL, see below). These rules may evolve due to acquired experience or agreed request from the community.
A version of the rules exists with examples and in a near future illustrations. This document Cannot be redistributed or copied without the authors permission.
An extension mechanism exists in order to complete the existing rules due to the specificities of the world you are playing in (you can certainly play using the basic rules in a science fiction world but it will be easier for the Game Master not to search any time he wants something done). As it is only one extension is available (there again french version only) : Psis powers. This extension is available but cannot be redistributed or copied without the authors permission. These rules are in a beta version and will evolve.
The “Open Game Licence” has been written by the Wizard of the Coast company. This License may be characterised thanks to the following principles: