Text (LG+errata): Instant and enchantment spells you cast cost up to {2} less to cast. [Oracle 2009/07/08]
Only reduces the generic mana portion of a spell's cost. If the spell does not accept generic mana or accepts less than {2}, you get a reduced or null effect from this card. [Duelist Magazine #2, Page 9]
Only affects its controller, not all players. [bethmo 1994/06/15]
Only works on instants and enchantments. It does not work on sorceries, so you can't use it on a Fireball. [D'Angelo 2000/03/03]
Although the apparent cost is reduced, the "mana cost" of the spell for reasons of Spell Blast or such is still the full amount. [Duelist Magazine #2, Page 9] Just think of the Matrix as contributing {2} to the cost, not reducing it.
Multiple Matrices do add up. Two will contribute up to {4} toward the cost, and so on. [bethmo 1994/06/29]
Extended tournaments (see Rule 913) have always banned this card.
