Where Does Modern Go After The Banning Of Arcum’s Astrolabe?

Arcum’s Astrolabe leaving Modern sent subtle but undeniable ripples through the metagame. Ari Lax breaks down the consequences.

Arcum’s Astrolabe, illustrated by Igor Kieryluk

On the list of banned Modern cards, Arcum’s Astrolabe is a weird one. Distinctly less weird than Mycosynth Lattice, but weird nonetheless.

Gitaxian Probe

Arcum’s Astrolabe itself is almost a null piece of cardboard. The closest equivalent on the Banned List is probably Gitaxian Probe. Its impact on a game or the wider metagame is rarely direct; its impact is via the cards it directly enables.

Ice-Fang Coatl Uro, Titan of Nature's Wrath Mystic Sanctuary

The big three cards that were consistently tied to Arcum’s Astrolabe are Ice-Fang Coatl; Uro, Titan of Nature’s Wrath; and Mystic Sanctuary. How do they all fare in the updated Modern metagame?

Tired of These Modern Format Snakes

Ice-Fang Coatl

It should be obvious Ice-Fang Coatl gets worse with fewer playable snow permanents, but it’s layered. Not only was Arcum’s Astrolabe the extra snow permanent you needed to get Ice-Fang Coatl deathtouching on Turn 2, it also made it painless to run enough Snow-Covered basics to make that happen.

Search for Tomorrow Scapeshift

Ice-Fang Coatl is still playable in Modern after this change, but it’s not broadly playable. It is almost certainly tied to Search for Tomorrow and other reasons to play a ton of basic lands, and conveniently ties into Scapeshift wanting cantrip interaction to solve the classic “Scapeshift plus lands is eight pieces of cardboard” issue.

Death's Shadow Gurmag Angler

The huge winners from this change are cards that really don’t want to play against opponents with cantrip-Condemn. This is mostly stuff that was best known for being cheap and bigger than Lightning Bolt: Death’s Shadow, Gurmag Angler, Tarmogoyf

Chalice of the Void Thought-Knot Seer

Eldrazi Tron gains on a couple of levels. The obvious is that attacking Thought-Knot Seer into Ice-Fang Coatl isn’t great. Temur specifically is now back to minimal good ways to kill big squiggly doofuses. 

Path to Exile Terminate Maelstrom Pulse

The less obvious is that Modern exists on a paradigm of one-mana removal being powerful but slightly specific, two-mana removal being general, and three-mana removal being general with upside. Ice-Fang Coatl broke this by being a two-mana general removal spell with upside, and the three-mana removal with upside has always been clunky bar Liliana of the Veil.

That means decks have to decide whether they want to play a potentially blank and clunky Terminate, or whether they want to skew towards more efficient and maybe flexible options like Path to Exile and Lightning Bolt. When they go for efficiency, Eldrazi Tron is well set to punish them. Not only does Eldrazi Tron exist to blank Lightning Bolt, but Chalice of the Void is much more effective against Snapcaster Mage and Path to Exile than Ice-Fang Coatl. Small edges for sure, and effectively even smaller since Eldrazi Tron was always fine against these control decks, but you take what you get.

Champion of the Parish Soul-Scar Mage

Do people even attack with creatures anymore? It’s likely a slight upgrade to Five-Color Humans if Snapcaster Mage shows up more since it makes Meddling Mage and Thalia, Guardian of Thraben more powerful, and it’s a net loss for Mono-Red Prowess since Lava Dart is no longer a pseudo-Blossoming Defense that pings away their Coatl and pumps the squad, but these are all small. Five-Color Humans and Mono-Red Prowess are good when specific things happen, like combo rising up or Birds of Paradise being important, and both of those are degrees of separation from Arcum’s Astrolabe’s place in the metagame.

Lands and Titans

Uro, Titan of Nature's Wrath Mystic Sanctuary

The outlook for both Uro, Titan of Nature’s Wrath and Mystic Sanctuary is the same: they will still be about as good as before. There won’t be quite as many Uro or Mystic Sanctuary decks, but that will be because the loss around the margins gives other decks reasons to exist.

Steam Vents Watery Grave

Listen, people have played Cryptic Command three-color manabases in Modern since before it was called Modern, back when Gavin Verhey was organizing events where people put Bloodbraid Elf and Vendilion Clique into the same deck. Uro plus Mystic Sanctuary plus another off-color answer is not any more difficult to manage than Cryptic Command, Supreme Verdict, and Lightning Bolt. Uro even offsets the pain of a heavy fetch-shock manabase.

The cost comes because your mana is now something people can attack. One of the most successful non-Arcum’s Astrolabe decks of recent months is already playing Magus of the Moon and Pillage because they are actually good in this weird new Modern. Incidental Blood Moon is back to being a playable card, or maybe incidental Magus of the Moon since that one can’t be freely Force of Negation’ed.

Jeskai Control has been able to beat Blood Moon in the past with mana comparable to a Temur or Bant Uro deck, but it couldn’t completely ignore it the way Arcum’s Astrolabe decks could.

Fulminator Mage

Other midrange decks might be able to make inroads on the angle of attack as well. Fulminator Mage plus Kolaghan’s Command has always been an effective angle of attack against Jeskai Control out of Jund Midrange.

Urza's Tower Field of Ruin

The reverse approach of attacking their inability to play quite as many Field of Ruin is also enticing, but I would be wary of it working out. Not only have three-color decks with these kinds of mana requirements been fine with a couple of copies of Field of Ruin in the past, Mystic Sanctuary allows Uro decks to over-leverage more flexible land hate if they know Urza’s Tower is coming. Think about them playing an Assassin’s Trophy two or three times a game, or sideboarding into Molten Rain and doing the same. Even Aether Gust is a mess if your threat is Primeval Titan. It’s the Snapcaster Mage plus sideboard card scenario, but worse. 

The Actual and Tangential Impacts


Honestly, you can probably just build the same midrange decks you did before with Opt or Thought Scour instead of Arcum’s Astrolabe and be off to a good start as long as you weren’t leaning too hard on Ice-Fang Coatl as a specific answer. Play some Drown in the Loch or whatever; it will be fine. If you compare Arcum’s Astrolabe to Gitaxian Probe, that makes tons of sense. The best Gitaxian Probe decks like Gifts Storm, Simic Infect, and Grixis Death’s Shadow are still around in Modern today, just without Gitaxian Probe.

Bloodbraid Elf Death's Shadow

People will fall back on other old midrange decks, thinking this is a window to try them. It probably isn’t. Uro and Mystic Sanctuary still make the Simic-based decks more broadly powerful, even if their mana now costs some more life. I think there’s room for exactly Death’s Shadow to return to the higher tiers of the format, since the Uro decks are bad at punishing someone for using their life total as a resource and it can out-maneuver and out-size a slower 6/6. 

Scavenging Ooze

If for some reason you insist on playing all the Overgrown Tombs everyone else knows not to, Scavenging Ooze had better be in your list, and honestly Cling to Dust too. It’s just as much because you can’t beat Mystic Sanctuary as it is for Uro. I wouldn’t actually look at playing a Thoughtseize / Tarmogoyf deck, but if I were forced to I would look back at some of the older Golgari versions.

Teferi, Time Raveler Narset, Parter of Veils

Planeswalkers will become more important in the midrange mirrors of the format without a random 1/1 Snake to chip away at their loyalty. The current Uro decks literally have no way push into a Teferi, Time Raveler or Narset, Parter of Veils that is just hanging out, especially since Teferi’s -3 lines up so well against Uro. Force of Negation still exists as a way to punish tapping out for these spells, but you can just play a lot of them. If any fair deck is a winner on this change, it’s probably Azorius Control. Or maybe just Bant Uro. Level 2 will be realizing Eliminate or Abrupt Decay is pretty good and showing up with Sultai Midrange.

Urza, Lord High Artificer Thopter Foundry Emry, Lurker of the Loch

Things have not been good for artifact decks since the egregious Oko era. For the various midrange payoffs that just needed cardboard with the right type line, they got way worse. If you like artifact-related things, I would look into The Ozolith and Hardened Scales.

Field of the Dead

Field of the Dead is a second-order loser here. Primeval Titan decks will need to speed up to handle all the things suddenly unlocked by Ice-Fang Coatl not stepping into combat, and Field of the Dead is not one of their faster cards. If Death’s Shadow is the predictable winner, then Temur Battle Rage makes short work of Zombie chump blockers.


Remand is another loser here. It was best as the free way to punish escaping Uros, and even if the deck is still good, it is worse and will be less popular. The faster creature decks that have always been the bane of Remand will also be on the upswing.

So…What’s the Point?

I just outlined the impact of an Arcum’s Astrolabe ban as something that would result in minor changes to the format. Uro-based midrange is still good. Creatures get a bit better, but only in the sense that said Uro decks have cost to their removal slots instead of the first four being cantrips with power and toughness. You can attack their mana, but it’s not a slam dunk by any means.

And it’s not like other decks weren’t competing with Uro-based decks before and doing a fine job of it. It was a soft kind of dominant in the format.

So why was Arcum’s Astrolabe banned?

Because Modern is the competitive equivalent to Commander, and Arcum’s Astrolabe ruined that for a portion of the format.

Splinter Twin Karn Liberated Gitaxian Probe

The golden age of Modern was not Splinter Twin versus Birthing Pod. It wasn’t the early days of discovery. It wasn’t the Gitaxian Probe era.

The best Modern has ever been was 2018. 

Hollow One Valakut, the Molten Pinnacle Hardened Scales

Ever since the “Turn 4 rule” early stages of the format, Modern has existed with a goal: not to enforce a specific pattern of play on the format, but to ensure nothing ever sits above everything else in a clear and unstoppable way. As long as you are within a die roll and a sub-par opening hand of being ahead in a given game with a wide range of strategies, Modern is doing its job.

Krark-Clan Ironworks

This property by itself can insulate the format from more borderline issues rapidly spiraling out of control. Ironworks Combo was extremely powerful and pretty good at shaking off hate, but it wasn’t that much faster than everything else or absolute in its resilience. It survived most of a year before being hacked away. Faithless Looting and Mox Opal had similar trajectories, where they got away with a lot more nonsense than they would have in any other format before a ban.

Tireless Tracker Lingering Souls Bloodbraid Elf

This same margin extended to the fair decks of the format. If you thought Thoughtseize-based midrange was good, that still meant you could play Golgari, Abzan, Jund, or Mardu, all of which had unique play patterns and upsides in narrow corner cases.

Again, that feeling of choice. That you have small choices, your opponent has small choices, and these all intersect to make more distinctive games, to make almost self-correcting matchups, where if you’re in the ballpark of good for the format you always are competing. Merfolk beat Affinity in a Grand Prix finals once, so anything is possible in Modern.

Arcum's Astrolabe

Arcum’s Astrolabe breaks down those barriers. “Or” becomes “and,” or “and but” becomes “why not have it all?” Uro being so much better than everything else certainly doesn’t help, but Arcum’s Astrolabe is what blurs all the lines.

Island Snow-Covered Island

The basic land thing just made this even more visible and egregious. Talk about denying a fundamental choice of the game. Maybe I’ll be more willing to ignore this if they printed white-bordered Snow-Covered Mountains in the future, but pushing strictly better basics to replace normal ones is basically like deleting all the skins from your MOBA or shooter.  

Deathrite Shaman

This is not the first time we have seen this issue of homogenizing fair decks create problems for the format, but this time we are starting from the right side of the ban. If you let Uro hang around, it might just be a Bloodbraid Elf. Mystic Sanctuary is horrible and miserable when you lose to it, but at least it and Uro say “graveyard” on them and give you some direction towards Relic of Progenitus as a way to fight back.

If you let Arcum’s Astrolabe hang around, I don’t know what the end result is, but it looks really similar to what we saw in Modern until Monday. Or what we still see in Legacy — some amorphous blob of the best raw cards, with unattackable perfect mana, with cantrip removal, and without choices to make. That’s a Modern that isn’t Modern. More than a slightly better midrange deck, that fundamental violation of the format’s ideas can’t stand.

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