All 10 Addendum Cards in Magic Ranked

Last updated on March 26, 2024

Unbreakable Formation | Illustration by Matt Stewart

Addendums are usually associated with legal documents and contractual paperwork. All the fun things in life. Appropriate then, that Magic introduced the addendum ability as a guild mechanic for the Azorius Senate, the literal fun police of Ravnica. Nothing screams riveting gameplay like a mechanic that reminds me of the bed bug addendum on my leasing agreement.

It’s a quirky little ability to add to the flavor of the Azorius guild, the wonderful Ravnicans who brought us such favorites as forecast and detain. It also asks you to play poorly for little upside. Or play better, depending on the circumstances. Either way, it’s a strange but completely forgettable way to encourage you to play your instants at sorcery speed. You know, the one thing that no Magic player has ever wanted to do.

What Are Addendum Cards in MTG?

Emergency Powers | Illustrations by Chris Rallis

Addendum is an ability word that grants an instant an extra ability if you cast it during one of your own main phases. This usually means casting the spell at sorcery speed, though you can still respond to other spells and abilities and get the bonus even if the stack isn’t empty so long as you’re casting the spell during your main phase.

Addendum was used as the Azorius () mechanic in Ravnica Allegiance (RNA). Of the 10 addendum cards, nine were printed in RNA, with Contractual Safeguard printed in New Capenna Commander, and nine of them are instants. Addendum can exist on any card type, though it only makes sense on cards that can be cast as instants.

Note that there are a few cards that have the same functionality as an addendum card but don’t use the actual ability word. Return to Dust pre-dates addendum, and Tail Swipe came after, neither of which use the term. Since there’s been no errata to change similar cards, we’re only looking at cards that actually spell out addendum in their rules text.

#10. Arrester’s Zeal

Run of the mill combat trick. Arrester's Zeal is the finest of fine tricks in Limited or casual intro-level decks, but it’s not beating any of its competition in that market. It’s also counter-intuitive to incentivize players to use their instant-speed tricks as sorceries.

#9. Code of Constraint

Passable, but also passable. Code of Constraint was reasonable in RNA Limited, but I have trouble seeing it in other formats. Maybe Hylda of the Icy Crown can give it a home? The design is strange too. Using it as an instant misses on the addendum ability, but using it as a sorcery makes the -4/-0 ability useless.

#8. Arrester’s Admonition

Despite my love of bounce spells, it’s hard to recommend Arrester's Admonition in any format where Repulse is legal, which is most of them. I’m struggling to think of a niche where you’d want Admonition over other more efficient bounce spells.

#7. Summary Judgment

In a world of Commander where Swords to Plowshares is legal and costs less than a dollar, Summary Judgment isn’t making the cut. Take the ordering of the bottom half of this list with a grain of salt, their ranks are all somewhat interchangeable.

#6. Sphinx’s Insight

Sphinx's Insight was important in Dovin's Acuity and Clear the Mind decks from RNA, but I’m guessing you didn’t come here for RNA draft advice in 2023. The life bump is small enough that I’d rather hold my mana up and have options instead of firing this off on my turn in most cases.

#5. Sentinel’s Mark

It’s not great, but at least Sentinel's Mark being an enchantment makes it stand out from the rest. Like Arrester's Zeal, it’s a combat trick you’re supposed to cast at sorcery speed, but this one sticks around and spots you lifelink for a turn. Cute, but I’ll stick to my instant-speed tricks.

#4. Precognitive Perception

Here’s where we get to talk about playable cards. Precognitive Perception was printed at a time when every set was contractually obligated to include a 5-mana draw-3 blue sorcery, and this take on the formula wasn’t much different than any other. Problem here is that decks that want this effect don’t want to tap out on their own turn, so you might as well nix the addendum clause altogether and call it Jace's Ingenuity. Fine card, but not a great addendum incentive.

#3. Contractual Safeguard

On face value, Contractual Safeguard lets you spread out a counter on one creature to all your creatures, but casting it on your turn spots you a free shield counter if you want to use that instead. That gives all your creatures a layer of protection, though doing that at sorcery-speed isn’t going to catch anyone off-guard like an instant-speed protection spell would. Even spreading a +1/+1 counter around at this cost isn’t great, so the flexibility of the card falls a little flat.

#2. Emergency Powers

Emergency Powers is the best use of addendum as an incentive. An instant-speed wheel is already a card some EDH decks are interested in, though having white in its cost means it doesn’t fit with many of the usual wheel-based commanders. Still, casting Powers as a sorcery gives you a shot at “refunding” your mana if you find something worth putting into play.

#1. Unbreakable Formation

Unbreakable Formation isn’t quite up there with the best protection spells of all time, but it’s in the conversation and holds up as a budget alternative to Teferi's Protection. You can use it aggressively, though you’re rarely incentivized to do that. Playing both offense and defense means you’ll almost always find a use for it, and the card sees a healthy amount of play in EDH.

Best Addendum Payoffs

You’re going to have a tough time looking for payoffs good enough to play most of the addendum cards over more powerful options. Even if you found a borderline reason to run some of the weaker ones, chances are there are other easily accessible cards that beat them on power level, even if you’re regularly getting the addendum bonus.

One of the most explicit payoffs is Dovin's Acuity, printed in RNA alongside the initial batch of addendum cards. It’s an engine card that stabilizes your life total and draws cards so long as you’re willing to cast instants during your own turn. Of course, Acuity works with any instants, not just addendum cards, so you could just ignore addendum altogether and it still works fine.

Since most of these cards are instants, you could bias towards spellslinger payoffs that care about casting instants, though that still begs the question, why these cards specifically? Maybe the true payoff is the satisfaction you get against an opposing Grand Abolisher, who forces you to get your addendum bonuses. Take that, stax!

Is Addendum a Triggered Ability?

Addendum is neither a triggered nor activated ability. It’s just an effect on a card and doesn’t put any additional spells or abilities on the stack outside that initial card. Countering a spell with addendum means none of that spell’s effects happen, including the addendum text.

Can You Stifle Addendum?

Stifle and other effects that counter activated and triggered abilities can’t target addendum, since the actual addendum ability is none of the above. In fact, addendum is hardly even an ability. It’s an ability word, which means it’s just there as flavor text to tie together a bunch of spells with the same general design.

You can use Counterspell on an addendum card, but you’re just targeting the spell in this case, not the actual addendum ability.

Wrap Up

Contractual Safeguard | Illustration by Gaboleps

I suppose this will serve as our addendum to this discussion, eh? Now if you’ll just sign and date here, here, and here….

Addendum was a neat experiment to try and show players that it’s alright to play instants at sorcery speed, but the bonuses presented on the cards weren’t pushed enough to give them any staying power. That means most of the addendum cards that exist are stuck in Limited limbo and rarely see play elsewhere, and the ones that do are still almost always cast as instants. If they’re going to explore this design space more in the future, we’ll need to see more designs like Return to Dust or Careful Consideration to make it appealing or more payoffs like Dovin's Acuity to tie everything together.

Are you an addendum lover, or have you found a good use for addendum cards outside Limited? Do you want to see the mechanic make a return? Let me know in the comments below or over in the Draftsim Discord.

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