Jace's Sanctum

• WOTC Official Reminder Textofficial rules
  Scry — Look at the top N cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.

• WWizards of the Coast2015-06-22
  Official Ruling
  The first ability of Jace’s Sanctum can’t reduce the colored mana requirement of an instant or sorcery spell.
• WWizards of the Coast2015-06-22
  Official Ruling
  Jace’s Sanctum’s scry ability will resolve before the instant or sorcery spell that caused it to trigger.
• WWizards of the Coast2015-06-22
  Official Ruling
  If there are additional costs to cast an instant or sorcery spell, apply those before applying cost reductions.
• WWizards of the Coast2015-06-22
  Official Ruling
  Jace’s Sanctum can reduce alternative costs such as miracle or overload costs.

Rulings via Scryfall