Oftentimes, new mechanics are set aside, to be discussed only in terms of their impact on cards. Today, I am going to flip the script and go into detail about surveil. This mechanic is the most interesting part of Guilds of Ravnica to me, and while it may not happen immediately, I expect that it will have an impact on Modern.

Surveil is potentially the most powerful mechanic in Guilds. It's an improved scry. It's also a graveyard mechanic, and those can be broken (hello, dredge). I set out to discover whether surveil is good enough in Modern to justify the mana cost of its spells. Thus far, my results have proven suggestive, but inconclusive.

Surveil in a Vacuum

While there are a number of interesting cards featuring surveil, I find the mechanic itself the real draw. Surveil is scry, but instead of scrying to the bottom of the library, cards go directly into the graveyard. Obviously, mechanics like delve need graveyards filled. However, for many decks, the graveyard is an extension of the hand; Faithless Looting might as well say "draw 4" in Bridgevine, for example. Surveil could function as card draw in the right deck.

More subtly, surveil removes the awkwardness associated with scrying cards to the bottom even in decks without graveyard synergy. Moving unneeded cards off the top of the deck is great, but the crack of a fetch shuffles them back into rotation.

Surveil in Context

Wizards appears to be perfectly aware of this fact and has adjusted the cards to compensate. Looking at the entire set shows that cards with surveil aren't aggressively costed, at least for Modern. The clearest example of this principle is Discovery, or Preordain with surveil for a mana more. Even when they're not, most other cards with surveil aren't going to floor anyone on pure power, generally going on unexciting creatures.

However, there are a number of spells with Modern-playable effects that have surveil. Were Preordain legal I'm certain every blue deck would play a full set, so Discovery is plausibly playable. The question is whether surveil's extra power warrants the additional cost.

One interesting side effect is that surveil is effectively a card economy mechanic. Most surveil cards have a primary effect, and then surveil is included almost like a cantrip. Many decks already run cards like Thought Scour or Mishra's Bauble whose primary purpose is to fill the graveyard. In that vein, Thought Erasure is like combining Scour and Thoughtseize. It's not as powerful or efficient as either card individually, but in very tight decklist that needs both effects, it could be better.

Mission Accepted

The natural place to start my investigation is Mission Briefing. After it was spoiled, discussion lit up everywhere about it unseating or complimenting Snapcaster Mage. It is also the only surveil card I've seen seriously discussed for Modern: Snapcaster is a Modern staple, and Briefing is a tweaked Snapcaster. Instead of leaving a creature behind, Briefing digs for the card to be "flashed back." Briefing also doesn't target, so Surgical Extraction isn't a clean answer and Scavenging Ooze is less effective. Those are some reasonable upsides.

Complications

Unfortunately, they're not reasonable enough. I tested Briefing in a standard Jeskai Control shell in lieu of Snapcaster and it just didn't work. The fact that Briefing is an instant, and not a creature, is worse than I initially appreciated. Control decks in general and Jeskai in particular lean on Snapcaster being a creature heavily because it generates a lot of card advantage. Even with planeswalkers and Search for Azcanta, without Snapcaster, the deck can struggle to establish a lead early. That 2/1 can trade with opposing creatures, be bounced with Cryptic Command, or just win the game through attacks.

I could see Briefing becoming Snapcaster 5+, but that brings up a host of new questions. Cutting answers is precarious as every slot is precious, and lowering the answer density, even with a powerful digging spell, meant I was falling behind more easily; often, I was just digging through air. It's possible that redesigning the deck would solve that problem, but I'm skeptical of the benefits. Replacing the current instant-speed dig spell, Opt, was basically a wash because the additional cost and lack of cantrip was equaled by the late-game value. Surveiling cards put back with Jace was valuable, but never game changing. It just didn't feel necessary, even if there was value to be found.

Opportunities

With the control deck tests not going anywhere, I instead explored its utility in combo decks. Snapcaster has only really seen play in slower fair decks since unfair combos like Storm don't need the card advantage or clock from Snapcaster. They need to find specific combo pieces and cast them. Since briefing is able to help with both parts, I swapped it for Opt in my Storm list and started testing. My theory was that it would serve as both a means to dig towards missing combo pieces and as a way to restart the combo should I fizzle.

It turns out that Storm, or at least the typical configuration, doesn't really want this type of effect. Briefing is just too mana-intensive. Double blue is surprisingly hard to come by in Storm, and not benefiting from Baral, Chief of Compliance stranded Briefing in hand. The best use in theory is finding and Briefing Gifts Ungiven, but that plan cost far too much mana for Storm to reliably handle.

However, I mentioned this to a colleague of mine who plays Ad Nauseam, and apparently he's been working with Briefing, too. The cost is easier to manage in Ad Nauseam thanks to the artifact mana and higher land count, and he has fewer ways to find his combo than Storm. He's also so dependent on actually drawing Ad Nauseam that any help is highly appreciated. He hasn't fully integrated Briefing yet, but he's confident soon combo players will adopt the card.

If We Search Hard Enough

The reason I'm convinced that surveil will eventually pay off in Modern is that it already has, kind of. Search for Azcanta is a playable card in control decks and the front side, arguably the game saving side, is surveil 1 without the keyword. True, it also has a considerable upside going long, where the actual surveil cards use surveil like a cantrip effect. However, Search only belongs in control decks, while surveil cards could go anywhere.

That doesn't necessarily mean that they should. As noted, surveil cards cost about a mana more than their non-surveil counterparts. The current Modern metagame really promotes mana efficiency and probably prices surveil out of fair decks. Even when that isn't the case, the real question is why run surveil cards? Nightveil Sprite is technically Search on a stick, but what deck wants to attack with a 1/2 Faerie in the first place, even with upside? While there could eventually be a creature deck that wants that effect, I don't know that they'd be willing to run an anemic creature and I'm certain that the deck doesn't currently exist. That said, combo decks have historically been willing to play less powerful or efficient cards if it fills the right niche.

Testing the Hypothesis

There are a lot of caveats when it comes to surveil in combo decks. Storm and similar combo decks aren't interested in two mana cantrips besides Manamorphose. Decks that want to fill their graveyards in a hurry have Stitcher's Supplier and Thought Scour. The deck that wants surveil is one that needs to find and cast a specific instant or sorcery and is looking for other specific cards in its graveyard and can afford to pay extra for card economy. It's a deck that needs disruption and digging but lacks room for both.

The only deck I know of that fits this description is Bubble Hulk. The deck needs to find and cast Makeshift Mannequin or Footsteps of the Goryo on a Protean Hulk in their graveyard. The lists tend to be fairly tight, and yet they run cards like Taigam's Scheming and Izzet Charm to assemble the combo, so I could see double-duty cards like Thought Erasure making the cut.

To test my theory, I proxied Clinton Whitehurst's deck from the previously linked article, goldfished it a few times, then switched the Charms for Erasure and the Schemings for Briefing.

While Scheming and Charm see more cards than their replacements, it wasn't enough more to really matter. The goldfish speed and gameplay didn't measurably change between the two versions, though Briefing into Faithless Looting was surprisingly powerful. It did feel clunkier, but that may have been that the mana wasn't optimized for my changes.

Proof of Concept

A few test games against decks from my Banlist Testing gauntlet with each version later, and there was still no clear answer. Izzet Charm was better against Humans because it digs deeper than Erasure and can kill a Meddling Mage or Kitesail Freebooter. Against Tron and UW Control, Erasure was much better at protecting the combo because it disrupts proactively. Briefing's impact was difficult to determine, as it set up some very interesting plays but was less castable compared to Scheming. However, the fact remains that the concept works even if the execution was off.

The Missing Piece

The main thing I learned in my dive into surveil is that something is missing for it to really shine. Fair decks aren't going to run a surveil card over their more efficient counterparts. There needs to be some kind of payoff to using surveil to selectively set up your graveyard rather than filling it with random cards and that doesn't exist yet. If it does, Thought Erasure and Discovery will be the headliners, though someone adopting Nightveil Sprite isn't impossible. 

That said, the power of Discovery may push it into the mainstream anyway. The mana cost is a huge strike, but Modern is a bit thin on selective cantrips. In particular, I can see a theoretically resurgent Grixis Control choosing Discovery over Serum Visions. Prior to Death's Shadow pushing it out, Grixis Control was about the early cantrips setting up both Tasigur, the Golden Fang and Snapcaster Mage while preparing the reactive answers. More contemporary lists have used Search for Azcanta for that purpose. I could see a version using discard on turn one both as disruption and to see what they need to answer and then Discovery to actually find the answers or finding and setting up a fast Tasigur or Gurmag Angler.

Combo decks are another story. Mission Briefing in particular will see play. Whether as the means for key card combos to find and resolve their cards under discard pressure or to prevent fizzling is hard to say. I'm confident we'll see Briefing in Ad Nauseam soon, and I doubt it will be the only beneficiary. Non-Storm combo has been on the outs for a while, and Briefing could bring them back to light.

Patience is a...

Don't count surveil out just because it's a little pricy. The power contained within the mechanic is too great for it not to impact Modern. It may not make sense in every fair deck, but Mission Briefing in particular has a future in combo decks. With the right cards or the right metagame, I could see surveil becoming a real player in Modern.