Our Cubelock deck guide for The Boomsday Project expansion will teach you how to play this popular archetype. This Cubelock guide includes Mulligans, Gameplay Strategy, Card Substitutions, and Combos/Synergies!

Cube Warlock is a slow Warlock archetype first introduced in Kobolds & Catacombs. To be fair, the deck is very hard to classify – it has lots of Control elements (high cost cards, many removals), but very often you want to play it proactively. The deck also has some combos that you want to perform, and you could say that Carnivorous Cube combos bring it closer to a Combo build. In the end, the deck is somewhat of a mix between different archetypes, such as Midrange, Control and Combo, and that’s exactly what makes it so powerful.

Cube Warlock can adjust its play style depending on the matchup it faces. With lots of removal (especially AoE), healing and Voidlords, it stands a chance against most of the aggressive builds. And thanks to the Mountain Giants and Doomguards, it can put enough pressure on a slower deck.

Because the Standard rotation didn’t affect it much, Cubelock remained as one of the strongest decks in the early Year of the Raven meta. The only new card that’s an auto-include is Lord Godfrey, a very powerful late game AoE (much better than Twisting Nether against Aggro builds), but given that the deck kept most of its power, it has once again wrapped the entire meta around it… until the nerf patch happened.

Recent balance changes have hit this deck most. Between increasing the mana cost of Possessed Lackey (from 5 to 6) and reducing the healing from Dark Pact (from 8 to 4), the deck lost a lot of momentum. Does it mean that it’s no longer viable? No, not at all! Even though it lost a lot of its power, at the same time other players stopped teching against it heavily, so in the end, the deck is still good. While it doesn’t appear to be very popular, it’s a solid Tier 2 deck, especially in the higher ranks.

We’ve listed a popular version of Cubelock below, we’ll be updating the guide soon!

Cubelock Mulligan Strategy & Guide

Against Aggro you want to have early board-clears and life-gain cards, and against Control you want essential combo pieces.

VS Everything

Kobold Librarian – Cheap minions that draw cards have always been good, but this is one of the better ones. It activates Lesser Amethyst Spellstone , cycles through your deck, and provides you with a much needed 1-health minion for Defile that you don’t hate to put into your deck.

– Cheap minions that draw cards have always been good, but this is one of the better ones. It activates , cycles through your deck, and provides you with a much needed 1-health minion for that you don’t hate to put into your deck. Skull of the Man'ari – Pulling big Demons from your hand is your best way to win in the mid game. The slight downside is that you might not draw any of your big Demons by Turn 5 (although it doesn’t happen often).

VS Fast Decks

Higher Priority (Keep every time)

Defile – One of the strongest board-clearing tools in all of Hearthstone, Defile is amazing at getting you through the early game. Defile handily clears small minions, and is one of the only ways to do so while also removing Deathrattle-produced tokens.

– One of the strongest board-clearing tools in all of Hearthstone, Defile is amazing at getting you through the early game. Defile handily clears small minions, and is one of the only ways to do so while also removing Deathrattle-produced tokens. Doomsayer – The reason you play Doomsayer is that the card is amazing vs Aggro. When played on Turn 2, it usually pops and destroys the whole board. Not only you can clear some early game minions this way, but you also force your opponent to skip board development on his turn.

– The reason you play Doomsayer is that the card is amazing vs Aggro. When played on Turn 2, it usually pops and destroys the whole board. Not only you can clear some early game minions this way, but you also force your opponent to skip board development on his turn. Stonehill Defender – It’s not an amazing card, but it’s your only Turn 3 play, and it’s better to drop a 1/4 Taunt than just tap most of the time, especially vs Odd Paladin, where it can actually trade into some of the 1/1’s.

Lower Priority (Keep only if certain conditions are met)

Lesser Amethyst Spellstone – This card is pretty bad at first, but even after just a single upgrade, it gets amazing. That’s why you keep it with Kobold Librarian , so you can guarantee a 5 damage + healing on the curve.

– This card is pretty bad at first, but even after just a single upgrade, it gets amazing. That’s why you keep it with , so you can guarantee a 5 damage + healing on the curve. Hellfire – While it might seem like a desperate keep, your ability to clear the board in the mid game is often what wins you the matches vs Aggro decks. Keep it against decks that like to flood the board a lot, such as Odd Paladin.

VS Slow Decks

Higher Priority (Keep every time)

Mountain Giant – Against slow decks you can afford to spend your first few turns Life Tapping, which sets you up to play Mountain Giant on turn 4. Mountain Giants that early can often win you games, but it also soaks up opponents removal, making your later threats harder to respond to.

– Against slow decks you can afford to spend your first few turns Life Tapping, which sets you up to play Mountain Giant on turn 4. Mountain Giants that early can often win you games, but it also soaks up opponents removal, making your later threats harder to respond to. Possessed Lackey – After the nerf, Lackey is too slow to keep vs Aggro, but it’s still good vs slower decks. After all, you want to pull out those Demons from your deck somehow.

Lower Priority (Keep only if certain conditions are met)

Doomsayer – Keep when going second and the rest of your hand is okay. Even though it’s more of an anti-Aggro card, sometimes you can keep it vs slower decks too, in order to answer their early game plays and stall their board development. DO NOT keep it if you’re going first, because you will need Taps on Turn 2 and 3 to play Giant. Going second, you can Tap on Turn 2 and drop Doomsayer on Turn 3, setting up a Turn 4 Giant really well.

– Keep when going second and the rest of your hand is okay. Even though it’s more of an anti-Aggro card, sometimes you can keep it vs slower decks too, in order to answer their early game plays and stall their board development. DO NOT keep it if you’re going first, because you will need Taps on Turn 2 and 3 to play Giant. Going second, you can Tap on Turn 2 and drop Doomsayer on Turn 3, setting up a Turn 4 Giant really well. Carnivorous Cube – This deck is built to take full advantage of the Cube, and if you keep it in your opening hand you don’t have to find it. You probably want to have at least a Mountain Giant or Skull of the Man'ari before you keep a Cube though.

Cubelock Win Rates

Winrate stats are currently unavailable for this deck at the moment!

Cubelock Play Strategy

With this deck you’re trying to set up powerful plays with Carnivorous Cube, either to make an unbreachable wall or an OTK combo.

Vs Aggro

Games against Aggro aren’t different than usual. Most important thing is to constantly clear the board and survive. In case of Cube Warlock, the key moment is usually surviving until you clear the board and drop Voidlord your opponent can’t answer (e.g. he has no Silence). It can sometimes happen as soon as turn 6-7, although the biggest swing with Cube Warlock happens on Turn 10 – thanks to the Bloodreaver Gul'dan. But, how can you survive that long when your opponent is constantly trying to push damage?

Most important part is AoE damage. Your deck runs two AoE damage spells – Defile and Hellfire + a slightly different form of board clear, Doomsayer. All of those are really strong in different cases. Hellfire is just your generic 3 AoE damage – it’s enough to clear most of the early game minions your opponent will play. Defile is better when it comes to those tricky boards – if you can line up the health totals of minions, you can even clear 4-5 health minions, as well as everything up to that point. Doomsayer is easiest to counter, but also strongest in the early game, as your opponent will have to skip a turn if he can’t clear it. It’s also a good “proactive” stall tool – after you clear a board, you can drop Doomsayer to force your opponent to skip a turn. Very useful during later turns, when you have something you want to play next without being interrupted. Sometimes you can also drop two Doomsayers on a single turn – it increases the chance of them blowing up quite heavily. Yes, you use two cards instead of one, but it might be worth it if you need to stop your opponent from getting huge board.

On top of those, this build uses Lord Godfrey. Even though 7 mana cost seems quite expensive, it’s very useful, especially against those board flooding Paladins or Zoo Warlocks. Not only it should be able to clear the board quite easily (it’s almost impossible to play around it AND putting multiple minions on the board at the same time), but it also leaves a 4/4 body that you can get another trade with next turn.

One of the most important skill is picking the right AoE for the right situation. Generally, in the early game, try to rely mostly on the Doomsayer. Later in the game, it really depends on the deck you play against. If your opponent doesn’t really play 1 health minions, then you should take Defile value whenever you can. If he does – then you can be a little more greedy with it and wait for a good opportunity. Don’t use your AoE too lightly – Aggro decks usually have multiple ways to refill the board, so if you AoE down two small minions, you might not have a way to deal with e.g. Call to Arms or board flood from Zoo.

But, even with lots of AoE, your opponent will still deal damage – it’s just something you can’t help. For that reason, in order to keep yourself alive, you run quite a lot of healing. Sadly, the Dark Pact nerf reduced the total healing of your deck by 8, which is massive in Aggro matchups. Still, between 2x Dark Pact and 2x Lesser Amethyst Spellstone, you can heal for quite nice amount, not to mention that Bloodreaver Gul'dan is usually a game over for your opponent, not only because you resummon Demons, but also because you heal for 3 more per turn.

Preserving your life total is important, but don’t mistake not taking damage at all with preserving health. Kobold Librarian is still one of the best cards vs Aggro, even if you take 2 damage. If it trades into your opponent’s 2/1 (for example), then you indeed took 2 damage, but you saved probably 4 or 6 in the long run. Life Taps are similar – even though taking damage and doing nothing is terrible against Aggro, tapping brings you closer to your big Demons (and ways to summon them), as well as AoE and healing cards. You should still Hero Power in the early game, and in the mid/late game if you have free mana and still lots of health. Safe health really depends on the matchup and situation – e.g. aggressive Paladins don’t have a lot of ways to deal damage without board, but Tempo Mage can kill you from 20+ health over 2 turns, with no minions at all.

Voidlord is a key card when it comes to surviving. But one is often not enough – not only it can get Silenced, but opponents sometimes have ways to get through it (e.g. Sunkeeper Tarim). That’s why cards like Faceless Manipulator and Carnivorous Cube + Dark Pact are so great – you can extra copies of it, so now even if your opponent Silences or deals with one, he still has another to go through.

If you get to Turn 10, a big Bloodreaver Gul'dan is usually GG, assuming that you can revive at least one Voidlord (+probably a bunch of Voidwalkers and possibly some Doomguards). If you have Gul’dan in your hand already and you’re just a few turns off, try to not make any risky plays. Just clear the board constantly and heal up as much as you can. Turn 10 swing is going to win you the game almost every time, so there’s no reason to risk it. If your opponent somehow answered your board (e.g. Even Paladin running Equality combos – not really an Aggro deck, but you get what I mean), then try to Hero Power every turn and continue with your previous game plan of clearing the board. Now with a better Hero Power, there is no way that a faster deck will outvalue you.

Vs Control

When playing vs slower decks, just surviving is not enough. Cube Warlock is not a high value deck. You don’t run multiple tools that generate extra resources, or ways to win a slow, fatigue-oriented game. In the long run, lots of decks are going to destroy every threat in your deck (e.g. Control Warrior), destroy your deck (Rin, the First Disciple or just kill you through some combo (e.g. Mind Blast Control Priest can deal lots of damage from the hand after setting you up to 15 with Alexstrasza). Of course, it all depends on the match, but you usually have to just kill them before you run out of resources.

First and one of the most important cards in those matchpus is Mountain Giant. I’d say that around 1/4 of the games with Cube Warlock are won around Turn 6-7 thanks to the Giants. Dropping a Giant on Turn 4 is really big when your opponent can’t answer it right away, mostly because you can do so many things later while still putting pressure. Your opponent has to play defensively, while you can push. Most of the time, unless there is some high priority target on the board, you just push face damage. 8 per turn is a lot and can’t be underestimated, especially against Warlocks (which should already be around 20-24 health from the taps and Librarians). After dropping the Giant, you have a few things to do. You can play another Giant, copy the one you have with Faceless Manipulator, play Skull of the Man'ari. On Turn 6 you can either drop Possessed Lackey (good thing is that if you have something on the board already, your opponent might be too busy to worry about silencing it). You can also eat your Giant with Cube and Dark Pact it. The last play is especially powerful if you need to attack something and lose health in process. For example, your opponent drops a 5/5 minions. Hitting it, then dropping Cube and killing it results not only in healing your Giant up, but also getting an extra one. However, if you play a matchup in which putting pressure is important, you’d want to do that even on a full health Giant just to get an extra 8/8.

However, that aggressive push won’t always work. Your opponent might have an answer, or put a Taunt wall. If that’s the case, take the game a bit slower, especially with a very reactive hand. There is no harm in just clearing the board and waiting until Turn 10 swing or Cube combos to close out the game.

Talking about Cube combos – in slow matchups, it’s usually better to copy Doomguards than Voidlords. While Voidlords provide a huge wall, not only they aren’t aggressive enough, but Voidwalkers also dillute the Bloodreaver Gul'dan spawn pool. It’s a big issue a lot of players don’t think about – reviving 3-4 Doomguards is usually game-winning, while reviving 6 Voidwalkers and Voidlord is… not bad, but underwhelming. So it’s generally better to save the Cube combos for Doomguards. The best way to set those up is Skull of the Man'ari. Once it summons Doomguard, you go face (or bump it into something, you can even get the first one down to 1 health as long as it doesn’t die), then Cube + Dark Pact it, and then get another 10 damage. That’s already up to 15 damage, with two 5/7’s on the board your opponent has to clear. Then, if you go into your Gul’dan turn, you will most likely re-summon more Doomguards, often closing out the game as soon as Turn 10.

Since the deck runs no Siphon Soul or Twisting Nether, your reactive game vs slow decks is much weaker. You can still kill a single minion with Voodoo Doll + Mortal Coil / Dark Pact, but once your opponent puts two or more big threats, you might have a very hard time. That’s the problem you solve by simply putting pressure all the time. If you have minions on the board and your opponent is pretty low, he has to remove them / Taunt up / heal up all the time, leaving no room to develop. However, this strategy takes a huge toll on your value. If you constantly push, your opponent usually gets the better trades, removes your minions efficiently etc. and you often end up getting outvalued. It doesn’t matter as long as you can kill your opponent first, though.

Talking about the Hero Power, once you transform into DK, that Hero Power is often one of your main win conditions. Simply using it on your opponent every turn can put a lot of pressure on their health – like a better Hunter’s Hero Power. It’s best when you face a Warlock who hasn’t transformed yet. Generally, try to use it every single turn – in the best case scenario you “suck” their Hero, while deal with the board with removals like Hellfire, Spellstone etc. However, if you have a board yourself and clearing something will protect your board, it’s often worth to clear with the Hero Power too. It all depends on the context, how much burst you have, how much health your opponent’s at, board states etc.

Alternatively, since the deck runs 2x Stonehill Defender, there is also a chance that you will discover Rin, the First Disciple. She gives you an alternative win condition, especially against decks that can outvalue you. Against decks that can just kill you, like Mind Blast Priest or Quest Warrior I’d mostly ignore her and go for the pressure – you need to win fast. But she’s an amazing win condition for example against a Quest Priest or against a regular Control Warrior.

Card Interactions

Faceless Manipulator and Prince Taldaram (this build doesn’t run it, but he’s a viable option) summon the targets of Carnivorous Cube when they die if they copied it. If they copy a Doomguard , Bloodreaver Gul'dan is that much more likely to summon additional Doomguards when played. Also keep in mind that while targeting Carnivorous Cube is their intended purpose, they can also target opposing minions such as The Lich King .

and (this build doesn’t run it, but he’s a viable option) summon the targets of when they die if they copied it. If they copy a , is that much more likely to summon additional Doomguards when played. Also keep in mind that while targeting Carnivorous Cube is their intended purpose, they can also target opposing minions such as . If you think your opponent has Explosive Runes , you can use it against them by playing Possessed Lackey or Carnivorous Cube into it. You’ll still take four damage when you play Lackey, but the Cube absorbs all of it.

, you can use it against them by playing or Carnivorous Cube into it. You’ll still take four damage when you play Lackey, but the Cube absorbs all of it. Carnivorous Cube is a great way to punish your opponent for playing Doomsayer .

is a great way to punish your opponent for playing . Skull of the Man'ari and Doomsayer have an interesting interaction a lot of people don’t think about. Start of turn effects are resolved in the order they were played in. So if you play Doomsayer first and THEN Skull, even if you have a Demon in your hand, Doomsayer will proc first and only then your skull will summon a Demon. However, the other way around is more common. If you have Skull already equipped and a Demon in your hand, it would often be foolish to play Doomsayer, as that Demon will immediately die.

and have an interesting interaction a lot of people don’t think about. Start of turn effects are resolved in the order they were played in. So if you play Doomsayer first and THEN Skull, even if you have a Demon in your hand, Doomsayer will proc first and only then your skull will summon a Demon. However, the other way around is more common. If you have Skull already equipped and a Demon in your hand, it would often be foolish to play Doomsayer, as that Demon will immediately die. Another interesting Skull of Man’ari interaction is that it pulls out a Demon BEFORE you draw a card. So, as long as you have a Demon in your hand and you don’t suspect that your opponent will destroy the weapon, it is possible to finish turn with 10 cards in your hand and not overdraw. Whether it’s worth it or not really depends on the situation, but sometimes you really don’t want to play any card and it’s better to take a slight risk of him destroying the weapon than to let’s say play Hellfire vs no minions.

Cubelock Card Substitutions

Although Despicable Dreadlord and Vulgar Homunculus are excellent cards that otherwise have good synergy with the deck, you can’t include them because they derail your consistency with Possessed Lackey, Skull of the Man'ari and most importantly Bloodreaver Gul'dan. You really want Gul’dan to summon as many Doomguards as possible to end the game.

Skull of the Man'ari, Carnivorous Cube, Voidlord and Bloodreaver Gul'dan are absolutely irreplaceable. Other cards, however, including Doomsayer, Spiritsinger Umbra or Mountain Giant can indeed be replaced. Here are some of the cards you can consider using instead:

Siphon Soul and Twisting Nether – These cards are often run in Cube-based Warlock decks, and there’s nothing wrong with them. They are absent from this list to make room for Faceless Manipulator and Mountain Giant , so if you don’t have or don’t want to run that package these are good choices to replace them with.

and – These cards are often run in Cube-based Warlock decks, and there’s nothing wrong with them. They are absent from this list to make room for and , so if you don’t have or don’t want to run that package these are good choices to replace them with. Prince Taldaram – While it’s not really a “budget” replacement, if you have Prince, but you don’t have Voodoo Doll, you can drop all of the 3-drops and run Prince Taldaram instead.

– While it’s not really a “budget” replacement, if you have Prince, but you don’t have Voodoo Doll, you can drop all of the 3-drops and run Prince Taldaram instead. Faceless Manipulator – Again, if you’re missing one of your Epics/Legendaries, you can try out a Faceless manipulator. It’s a flexible card that fits into Cube Warlock really well – you can put more pressure by copying a Giant or Doomguard vs Control decks, or you can put another huge Taunt by copying Voidlord vs Aggro.

– Again, if you’re missing one of your Epics/Legendaries, you can try out a Faceless manipulator. It’s a flexible card that fits into Cube Warlock really well – you can put more pressure by copying a Giant or Doomguard vs Control decks, or you can put another huge Taunt by copying Voidlord vs Aggro. Bloodmage Thalnos or Tainted Zealot or Kobold Geomancer – Spell Damage combos well with Defile , so slower Warlock often include it. Defile is a strong enough card on its own, so it’s not necessary to run any Spell Damage, but if you’re looking for spots to fill this is a good place to look. Each of the cards above have their individual strengths. Thalnos draws a card when he dies, Zealot adds Spell Damage to an additional Defile tick, and Geomancer is guaranteed to be in your collection!

or or – Spell Damage combos well with , so slower Warlock often include it. Defile is a strong enough card on its own, so it’s not necessary to run any Spell Damage, but if you’re looking for spots to fill this is a good place to look. Each of the cards above have their individual strengths. Thalnos draws a card when he dies, Zealot adds Spell Damage to an additional Defile tick, and Geomancer is guaranteed to be in your collection! Acidic Swamp Ooze – Weapon destruction isn’t a bad tech in the current meta. It works best against Tempo Mage (Aluneth) and in the mirror matchups (Skull of the Man'ari), but destroying a Vinecleaver or even Unidentified Maul versus Odd Paladin will also hurt him a lot. And most importantly – it’s a cheap way to fill some of the gaps in the deck.

P.S. If you don’t have Skull or Cubes, but want to play a similar deck, you can always try out the Demon Control Warlock. However, keep in mind that it still requires a different set of Epics to run.

Card Omissions

Cube Warlock is one of those decks in which you’d like to play more than 30 cards, but you have only 30 card slots. Some of the cards are missing simply because they HAD to be cut. It doesn’t mean that they are necessarily bad, and different lists might still run them, but you just had to remove something.

The most notable exclusions is probably Rin, the First Disciple. The Cube-less lists based around Voidlord are very passive, waiting for their opponents to run out of threats. For these decks, Rin is way more helpful than for this build. Rin dramatically accelerates the plan of running your opponent out of threats by removing their deck entirely. The strategy is effective in a lot of the Control matchups, but doesn’t go well in pair with the more aggressive strategy of this list. The turns Control Warlock decks would be spending to cast Rin seals are the turns this deck spends comboing Carnivorous Cube to end the game.

You might be skeptical about playing the slow Warlock deck without any copies of Siphon Soul or Twisting Nether, but they don’t fit this deck perfectly. These cards are very defensive, and great for outlasting your opponents threats, but this is a deck that wants to be proactive during the turns those cards would be necessary. You can still add one copy of each if you want, and it will make your value game much better. However, if you want to slow down and drop some combo consistency, you might as well just play the Demon Control Warlock instead.