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Ability Word
Introduced Ravnica Allegiance
Last Used New Capenna Commander
Typical Text Addendum — If you cast this spell during your main phase, ...
10 cards
{W} 50% {U} 30% {W/U} 20%
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Addendum is an ability word introduced in Ravnica Allegiance for the Azorius Senate.[1][2]


Spells with Addendum have additional or alternative effects if you cast the spell during your main phase. Addendum is found mostly on instants. The exception is Sentinel's Mark, which is an enchantment.


A similar cycle of "main phase matters" instants had previously been featured in Time Spiral.[3]

Addendum appeared as a one-off in the Streets of New Capenna Commander decks.



Sphinx's Insight {2}{W}{U}
Draw two cards.
Addendum — If you cast this spell during your main phase, you gain 2 life.


  • Addendum abilities of instant spells apply while the spell is resolving, not immediately after casting it. If the spell is countered, you don't get the addendum bonus. For example, if you cast Sphinx's Insight during your main phase, you gain 2 life during its resolution, after you draw two cards.
  • If a spell with an addendum ability is copied, the copy won't give you the addendum bonus. This is because the copy wasn't cast at all.


  1. Matt Tabak (December 17, 2018). "Ravnica Allegiance Mechanics". Wizards of the Coast.
  2. Mark Rosewater (January 7, 2019). "Building Allegiances, Part 2". Wizards of the Coast.
  3. Mark Rosewater (December 21, 2018). "Isnt the azorius mechanic the returning one from...". Blogatog. Tumblr.