Debates between wizards are never purely academic.

Arcane Melee

Instant and sorcery spells cost {2} less to cast.

The List

Commander 2013

Avacyn Restored

Arcane Melee can reduce alternative costs such as miracle costs.

Arcane Melee can’t reduce the colored mana requirement of an instant or sorcery spell.

If there are additional costs to cast a spell, such as a kicker cost or a cost imposed by another effect (such as Thalia, Guardian of Thraben’s ability), apply those increases before applying cost reductions.

The cost to cast an instant or sorcery spell with one generic mana in its mana cost will be reduced by {1}. For example, an instant spell with a mana cost of {1}{G} would cost {G} to cast.