Explorers of the Deep precon upgrade guide

Six of Explorers of the Deep's 36 lands tap for nothing but colourless, while fourteen of its spells want two blue pips by turn three. That mismatch is the first thing the eight swaps fix.

Hakbal is a 3/3 Merfolk Scout for {2}{G}{U}. Each Merfolk you control explores as your combat begins, him included, and when he attacks you put a land from your hand onto the battlefield or draw a card. The box builds the creature half of that properly: 33 of its 38 creatures are printed Merfolk, and Realmwalker and Metallic Mimic can be Merfolk too, one as a changeling and the other by naming the type.

The mana is where it's loose. Eleven of the 36 lands are colourless-only, always tapped, or both. Green has 21 sources against the 24 the calculator wants for a one-pip spell on turn two, which is 86.3% on the play. Blue's 25 clears that bar but not the 36 it wants for UU on turn three, and with fourteen spells asking for UU it lands at 71.8%. Those counts include the two Signets and the Sphere, Myriad Landscape for the basics it fetches, and Secluded Courtyard and Unclaimed Territory, which only make coloured mana for the creature type you name.

What are the best Explorers of the Deep upgrades?

In buying order. Eight cards in and eight out, $17.61 at the cheapest released printing of each (a few are promos), and none of them is a Game Changer.

1. Master Biomancer ($0.83). A 2/4 for {2}{G}{U}. Every other creature that enters under your control afterwards comes in with extra +1/+1 counters equal to its power, which is two. Hardened Scales and Branching Evolution are already in the box and both apply to counters a creature enters with, so with all three out a creature arrives with six: Scales first (2 becomes 3), then Evolution doubles it. It's an Elf Wizard, so Hakbal doesn't explore it and the lords don't pump it, which keeps its power at 2.
2. Jadelight Ranger ($0.30). A 2/1 Merfolk for {1}{G}{G} that explores twice as it enters. Hakbal explores it again every combat. With Topography Tracker out, each of those explores is replaced by two, and so is every explore Hakbal's trigger gives it.
3. Merfolk Branchwalker ($0.26). A 2/1 Merfolk Scout for {1}{G} that explores on entry. That one explore also fires Nicanzil, which puts a land from hand onto the battlefield tapped when a creature finds a land, and Merfolk Cave-Diver, which gets +1/+0 and can't be blocked whenever anything you control explores.
4. Floodpits Drowner ($0.52). A 2/1 Merfolk with flash and vigilance for {1}{U}. When it enters it taps a creature an opponent controls and puts a stun counter on it. For {1}{U} and a tap it later shuffles itself and that creature into their libraries. Leaves no token behind, and it has to be cast on an opponent's turn (see below).
5. Tishana's Tidebinder ($2.12). A 3/2 Merfolk with flash for {2}{U} that counters an activated or triggered ability when it enters. If the source is a creature, artifact or planeswalker, that permanent also loses all its abilities for as long as Tidebinder stays. It can't touch a spell.
6. Yavimaya Coast ($0.31), Rejuvenating Springs ($4.12) and Breeding Pool ($9.15). Three green-blue lands that enter untapped. The Coast always does and deals 1 damage to you each time it makes a coloured mana. Springs does while you have two or more opponents. Pool does if you pay 2 life, and being a Forest Island it also switches on Hinterland Harbor.

Four cards I looked at and left out. Cyclonic Rift is $29.75 and a Game Changer, so it would set a floor of Bracket 3 by itself. Misty Rainforest is $35.98 to fetch Forests and Islands the deck draws anyway. Dreamroot Cascade at $0.86 is the cheap stand-in for Rejuvenating Springs at a two-player table. Lord of Atlantis is $4.31, but the deck already runs five +1/+1 lords and a sixth adds one more point of power to a board the counters are already growing.

Five spells go, and a few that look like they should

Xolatoyac, the Smiling Flood is the one I'd argue about. It's a 6/6 for six in a deck that averages 3.11, and the end-step untap is real: every permanent with a counter on it untaps, so the Merfolk that attacked can block too. And its flood counter makes any land an Island, including an opponent's, which switches on the islandwalk of Master of the Pearl Trident, Cold-Eyed Selkie and Stonybrook Banneret against an opponent with no Islands. It goes because six mana is about twice the deck's average. If you want the trick without the body, Aquitect's Will does it for {U}, is itself a Merfolk spell, and draws a card if you control a Merfolk.

Reflections of Littjara copies each spell of the type you name. A copy of a creature spell becomes a token, so it's strong, but it costs five and does nothing the turn it lands. Kindred Discovery costs five too and stays, because it draws on both entering and attacking.

Ruinous Intrusion exiles an artifact or enchantment and puts counters equal to its mana value on one of your creatures, which sounds ideal and gives you a narrow window of targets. Beast Within and Ravenform already take artifacts. Thassa, God of the Sea needs five blue symbols among your permanents to be a creature at all, and the deck already makes creatures unblockable with Herald of Secret Streams, Kumena, Merfolk Cave-Diver and Merfolk Sovereign. Swiftfoot Boots protects one creature, and Kopala, Warden of Waves already makes your opponents' spells and abilities that target a Merfolk cost {2} more.

Six cards look like cuts and stay. Commit // Memory is a {3}{U} instant that tucks a spell or nonland permanent second from the top, and its mana value of ten is just both halves added together. Metallic Mimic is not off-type, because it becomes a Merfolk when you name one and then gives every other Merfolk an extra counter as it enters. Prime Speaker Zegana is a 1/1 that enters with counters equal to your biggest creature's power and draws cards equal to its power. Evolution Sage proliferates on every land drop, and between explores and Hakbal's attack trigger there are plenty. Merfolk Skydiver is a flying two-drop that puts a counter on something when it enters. Quandrix Command bounces a creature and puts two counters on another at instant speed.

Which lands leave, and the five tapped ones that stay

Temple of the False God, Reliquary Tower and Temple of Mystery leave. The first two make only colourless mana, and the Temple needs five lands before it makes two. Reliquary Tower's no-maximum-hand-size clause is already covered by Tishana, Voice of Thunder. Temple of Mystery enters tapped for a single scry, and Path of Ancestry already scries when its mana pays for a creature spell that shares a type with Hakbal. Yavimaya Coast, Rejuvenating Springs and Breeding Pool come in.

Green goes from 21 sources to 23 and blue from 25 to 27, with colourless-only lands down from six to four (Alchemist's Refuge, Karn's Bastion, Myriad Landscape and Rogue's Passage) and always-tapped lands from six to five. Green is still short for the cards that want GG. With 23 sources the check puts two green pips on turn three at 66.7% on the play, and Jadelight Ranger, Bygone Marvels and Prime Speaker Zegana are the ones asking for it. Cold-Eyed Selkie is hybrid, so blue can pay for it.

The five tapped lands that remain each do a job. Mosswort Bridge is a hideaway land that lets you pay {G} and tap to play its exiled card free while your creatures have total power of ten or more, which a board of lords and counters gets to. Llanowar Reborn has graft, so a +1/+1 counter can move onto the next creature that enters and wake up the counter cards. Myriad Landscape sacrifices for two basic lands that share a type, so two Forests or two Islands, and it ramps. Path of Ancestry scries when its mana pays for a creature spell that shares a type with Hakbal. Simic Growth Chamber is a bounce land, and Hakbal puts a land back down every attack. The three colourless lands that stay each have an ability worth a slot. Alchemist's Refuge gives your spells flash for {G}{U}, Karn's Bastion proliferates for {4}, and Rogue's Passage makes a creature unblockable for {4}.

Where the +1/+1 counters go

An explore that reveals a land gives you the land and no counter. One that reveals a spell grows the creature, and you decide whether the spell stays on top. Over a game the counters are what makes the board bigger, and a lot of the box reads them. Herald of Secret Streams makes your creatures with a counter unblockable. Zegana, Utopian Speaker draws a card when it enters if you control another creature with one, and gives those creatures trample. Inspiring Call draws a card per countered creature and makes them indestructible until end of turn. Vorel doubles the counters on a target, and Simic Ascendancy wins the game at twenty growth counters.

Wave Goodbye is the awkward one. It returns each creature without a +1/+1 counter, yours too. Cast it before combat and it hits your own board, but a second main phase after Hakbal's trigger has resolved spares every Merfolk that revealed a spell. Master Biomancer adds a second safeguard, since anything cast after it arrives with counters already on it.

Answers that leave nothing behind

Four answers in the box leave a body behind. Rapid Hybridization leaves a 3/3 Frog Lizard, Ravenform a 1/1 flying Bird, Beast Within a 3/3 Beast, and Curse of the Swine a 2/2 Boar for every creature it exiles. They're all playable, and none of them leaves the space empty.

Floodpits Drowner is the clean one, at a price. The stun counter means the tapped creature doesn't untap in its controller's next untap step, because the counter comes off instead. Cast on an opponent's turn, Drowner is still free to tap when yours begins, and the counter is still on the target. Cast on your own turn, the counter is gone before Drowner can tap. If you use the shuffle, Drowner goes into the library with the creature, so it's a one-for-one.

Tishana's Tidebinder covers the other gap. Nothing in the box stops a triggered ability once it's on the stack. Aimed at a creature's ability, it also switches off that creature's other abilities, but only while the 3/2 survives.

The deck after eight swaps

Average mana value goes from 3.11 to 3.02. Five-drops and above fall from eight to six, with the Xolatoyac and Reflections slots coming out, and two-drops rise from 19 to 20. There are 41 creatures instead of 38, 37 of them printed Merfolk, up from 33. Nothing in the box or the upgraded list is a Game Changer, which keeps the bracket floor at 1.

The upgraded decklist

Hover any card name on this page to see the card and what it currently costs. The cuts are Xolatoyac, Reflections of Littjara, Ruinous Intrusion, Thassa, Swiftfoot Boots, Temple of the False God, Reliquary Tower and Temple of Mystery.

Load into the deck builder Copy decklist Playtest the upgraded deck

“Load into the deck builder” opens this list in your account, pinned to the printings the box shipped, ready to edit or save. “Copy decklist” gives you plain text for Moxfield, Archidekt or Arena, with no account needed.

FAQ

Does Hakbal explore himself?

Yes. Hakbal is a Merfolk Scout, and his combat trigger covers each Merfolk you control. A land goes to your hand. A spell puts a +1/+1 counter on him, and you choose whether it stays on top of your library or goes to the graveyard. The explore trigger happens at the beginning of combat whether or not you attack. The land-or-draw trigger is separate and needs him to attack.

Which creature type should Kindred Discovery and Metallic Mimic name?

Merfolk. In the upgraded list 37 of 41 creatures are printed Merfolk, and Realmwalker (a changeling) and Metallic Mimic (once it names Merfolk) make 39. Only Master Biomancer and Evolution Sage fall outside it. Wizard is the next largest type at twelve, counting Realmwalker, so naming it would draw or pump on under a third of your creatures.

Is Wave Goodbye a one-sided sweeper in this deck?

Closer to one after a couple of combats than on turn four. It returns each creature without a +1/+1 counter, yours included. A Merfolk that explored into a spell has a counter and stays, and so does anything that entered after Master Biomancer. A Merfolk that found a land has none. Cast it in your second main phase, after the explores have happened, and count the creatures that found a land, because those are the ones that go.

Why isn't Cyclonic Rift in the list?

It costs $29.75 at the cheapest printing and it's a Game Changer. A single Game Changer sets a floor of Bracket 3, and neither the box nor the upgraded list has one. Cheap Merfolk with flash, Floodpits Drowner and Tishana's Tidebinder, give the deck instant-speed interaction without that jump.

What does the whole upgrade cost, and what can wait?

$17.61 for eight cards at the cheapest released printing of each. Breeding Pool is $9.15 of that and is reprinted in Star Trek on 13 November 2026, so its price may move. It's also the smallest gain, because Hinterland Harbor already enters untapped once you control a Forest or Island. Skip it first and the list costs $8.46.

Does Rejuvenating Springs enter untapped in a two-player game?

No. It enters tapped unless you have two or more opponents, and the count is of opponents you currently have, so a four-player game down to one opponent makes it a tapped land again. At a two-player table Dreamroot Cascade ($0.86) is the better pick, because it enters untapped once you control two other lands.

Why does Floodpits Drowner have to be cast on an opponent's turn?

Its stun counter is removed instead of letting the creature untap, and that happens in the opponent's next untap step. Flash it in on their turn and the counter is still there when your turn starts, with Drowner free to tap. Cast it on your own turn and the counter is gone before Drowner can use its tap ability, so it only works as a tapper that turn.