Earthdawn: The Age of Legend - Spell Matrices
One of the features of the Earthdawn setting is the magician's use of spell matrices, to protect them from the harmful magical energies and astral taint the Horrors brought into the world. In the Step System, spell matrices mainly serve as a mechanic for restricting the number of spells a magician can cast safely. The simple rules in Earthdawn: The Age of Legend do not necessarily require restricting spells, so the use of spell matrices is implicit: there is no mechanical impact unless your story has actual demand for such detail.
Some of you still want spell matrices to be more prominent in their games, however, so the following optional rules add mechanical detail to all magician characters. They also change the way spells affect the narrative of your game.