Octas is a Table Top Role-Playing game system based on the use of two 8-sided dice, numbered 0-7. It ostensibly uses the octal (base-8) numeric system, although this is largely hidden from players behind some simple conversion maths.
Octas/fallen is the default fantasy genre module for playing the game. For the base rules which this extension 'plugs' into, see the Octas System Reference Documents (SRD) accessible via the main Octas page."