Hearthpwn

I wrote an updated version for the Gadgetzan meta that also includes the discard package from One Night in Karazhan. It is a better list, I would fully recommend it over this one.

Introduction

Hey guys, I wanted to create a guide for the default Zoolock ladder list. This guide is aimed at players who are looking to learn Zoo, both beginners and intermediate players. An advanced player who's made it to legend a bunch of times but hasn't seriously played Zoolock yet will probably pick up a few helpful things as well. Zoo is a great, yet rather cheap deck to climb up in the ladder and eventually make it to legend. This 1400 dust deck list will get you there, provided that you're sufficiently skilled. The deck also teaches you a lot of concepts about Hearthstone, so if you're fairly new and you're looking to get good, this deck is an excellent choice.

Most of the information is gathered from various guides and sites across the internet, as well as pro player streams, especially RDU. I'm writing this to help myself synthesize some of this information, as well as to provide guidance to others who are trying to learn how to play Zoo. I'm also using it as a resource myself since I haven't fully mastered the deck yet. If you could point out mistakes, make suggestions, or link me to resources I've missed so far, I would find that very helpful! 

General Strategy

The general strategy of Zoo is to take board control from turn 1. We aim to populate the board with cheap but effective minions and trade efficiently by buffing the minions with cards such as Power Overwhelming, Abusive Sergeant, Dire Wolf Alpha, and Dark Iron Dwarf. Zoo is commonly misclassified as an aggro/face deck, but board control is an important element. If this strategy works, Zoo can close out games really quickly. If it doesn't and we lose the board, it is often hard to impossible to come back.

One of the difficulties when playing Zoo is to know when to go for face damage and when to control the board. It is key to identify which type of deck your opponent is playing. If you're facing an aggressive deck such as Aggro Shaman, Pirate Warrior, or another Zoolock, it is all about board control. Face damage is irrelevant for most of the game, if you control the board you will likely win the game. Against control decks, however, you'll start going for face much earlier, only trading if you have to. Key in these matchups is knowing what kind of removal your opponent has at his disposal, especially AoE. You don't want to have one 4 health minion and a bunch of 1 health minions against Druids, because a single Swipe will wipe your whole board out. 

Are you new to Zoolock?

If you don't really know what Zoolock is about, I recommend watching a few videos before you read on. Trump's Fearless Tapping video teaches you why the Warlock's hero power is so incredibly strong. Next, watch his Zoo Deck teachings video. While the decklist is outdated, all the basic concepts are still the same. Then, go on to watch his Standard Teachings: Zoo video. It's also a different deck list, but is set in the current, WotOG, meta. Finally, after reading the guide, I recommend that you go to RDU's twitch channel and check out the archives. Not only does he play this exact list a lot, he is also a world-class player who explains his decisions really well. Even a 20x legend Zoo player can probably pick up a few things from him.

The deck list

There are two basic Zoo archetypes: decks that run Doomguards, and decks that run Leeroy Jenkins. Both have their pros and cons, see e.g. this excellent discussion over on reddit. Doomguard is much better at contesting the board, while Leeroy Jenkins is the better finisher. Leeroy can pull off some miracle wins against control decks that a Doomguard list would lose, but it doesn't have the same kind of consistency. With Leeroy you can be a little more creative in terms of your deck list; with Doomguard you want to build the most consistent Zoo imaginable.

Amongst top players, the Doomguard version has been favoured for the last 2 months or so. Many tournament regulards can be seen playing a list like this one, with maybe 1-2 different cards. Doomguard Zoo is also the cheaper deck to craft, which is probably a concern for players who are reading a guide like this in the first place. Last but not least, the imminent Karazhan expansion looks to give discard Zoolock some nice tools, with many expecting Leeroy lists to completely fall out of favour. So Doomguard Zoo is the version we're going to be talking about.

Doomguard is the best card of this deck. A 5 mana 5/7 with charge is an insane card, but its battlecry is obviously not that great. The general idea of this deck is to play as many cards as possible early on and then to play Doomguard and get massive value from it. You're obviously getting the most value if you don't have any other cards in your hand, or if you only discard something like Argent Squire. 

Tech choices

At the time of writing (early August; pre-Karazhan), the ladder is dominated by Warriors. Warrior is a notoriously bad matchup for Zoo, in particular because of two cards: Fiery War Axe and Ravaging Ghoul. The guys over at vicioussyndicate.com did an in-depth analysis on the impact of Fiery War Axe. They looked at the winrates of matches in which Warrior played FWA either on turn 2, or turn 1 with coin. Against Zoo, FWA made a difference between 6.5% win-rate (Control Warrior) and 15% win-rate (Tempo Warrior). 

Zoo's best way to combat FWA is Acidic Swamp Ooze. The deck has 1-2 flex spots, one of which is generally occupied by either Crazed Alchemist or Acidic Swamp Ooze. The other one is either Gormok the Impaler or Dark Iron Dwarf. While Crazed Alchemist is very useful in a lot of situations, I believe that we really need the Ooze in the current meta. I've even seen people cut an Argent Squire in favour of a 2nd Ooze. It is not only the many Warriors, but also Aggro Shaman that Acidic Swamp Ooze can be the MVP against. Dropping the Ooze after they play Doomhammer often secures us the win. It is painful to cut a card as powerful as Crazed Alchemist, but I believe the Ooze to be better as it is vital against Warrior and Shaman, two of our most important matchups.

Cards that don't make it in this version of Zoo

The following cards all have properties that make them a better fit with Leeroy Jenkins lists. Doomguard is usually why.

- Soulfire: Great card, but we run the risk of drawing it together with Doomguard, which means that one of them will certainly be discarded. Can be a good situational pick from Dark Peddler, though.

- Sea Giant: Sometimes run in the Gormok the Impaler/Dark Iron Dwarf spot in this list, but it doesn't go that well with Doomguard, either. Sea Giant improves the Deck in some matchups, including the mirror matchup, but makes it even worse against Warriors. If you're playing tournaments and you ban Warrior, it might be a good idea to play Sea Giant instead of the Acidic Swamp Ooze. It'll help you against other Zoolocks and Aggro Shaman, 2 decks most of your competitors will run. 

- Mortal Coil: Another great utility card, but we can't really fit it in. Can be a good situational pick from Dark Peddler. I've seen Kolento play it in the current list instead of the Ooze, but I find it hard to see how it has more value than either the Ooze or Crazed Alchemist. 

- Brann Bronzebeard: I ran for a while, but I don't think he really has a place in a 2x Doomguard list. This deck is all about consistency, and we don't get that by adding another 3-drop. Brann raises the ceiling of the deck, but he also lowers its floor. The negative synergy with Doomguard and Flame Imp can also be a problem.

- Crazed Alchemist: A super strong card that one can use to either insta-kill minions such as Doomsayer or Flametongue Totem, or to use cards like an unbuffed Darkshire Councilman as a finisher. Definitely the first card I'd add to this list, I just like the Ooze a tiny bit better.

- Gormok the Impaler: Often played instead of Dark Iron Dwarf. Gormok is more powerful, while Dark Iron Dwarf is more consistent as well as much cheaper to craft. It is difficult to evaluate which card is better, though playing Gormok seems pretty greedy. I would certainly not recommend for anyone to craft Gormok at the moment, however. It seems likely that upcoming Zoo lists will add a discard synergy, Dark Iron Dwarf/Gormok is likely the first card to go. 

Replacements for adventure cards

Since the deck list is already quite cheap, I don't want to go into a lot of variations of it. The two cards worth mentioning are the cards from the adventure slots, Dark Peddler and Imp Gang Boss. You'll probably have to go with Flame Juggler instead of Dark Peddler and Harvest Golem or possibly Argent Horserider for Imp Gang Boss. It's also possible to tech in an Acidic Swamp Ooze or Crazed Alchemist in one of these spots, though you're deck will be a little less consistent if you make that change. The deck gets worse without these very strong cards, but the replacements aren't terrible, either.

Early Strategy

Turn 1:

It is crucial to play a 1-drop on the first turn. If you couldn't get any other 1-drop you'll play Abusive Sergeant;  in mirror matchups or against (a likely Aggro) Shaman it is usually correct to play Forbidden Ritual just to get something on the board. Don't do this against slower matchups, though.

Flame Imp is usually your preferred 1-drop, but there are exceptions, which we will get to in the hero-specific matchups. It is a really good 1-drop since it applies pressure very early on and can deal with most 2-drops. Here is a very rough and by no means set in stone order in which we would like to play our 1-drops:
Flame Imp >>> Argent Squire > Possessed Villager > Voidwalker >>>> Abusive Sergeant >>>>>>>>>> Forbidden Ritual.

Flame Imp is the tier 1 1-drop; Possessed Villager, Argent Squire, and Voidwalker are tier 2. If we have one of the tier 2 drops but not the Flame Imp, we usually play it no matter what. If we have multiple 1-drops, it gets a bit more complicated. In general, you prefer playing the Argent Squire over the Possessed Villager early on, since the Villager's deathrattle synergizes with Darkshire Councilman and Knife Juggler. Argent Squire is only better with Defender of Argus, so when it's foreseeable that you can use Argus on it in the near future you might hold on to the squire. However, sometimes you might want to play the Possessed Villager earlier since it synergizes better with Power Overwhelming than the Argent Squire. This is often the case against Druid and Shaman.

Example: you start the game with Argent Squire (or Possessed Villager), Voidwalker, and Abusive Sergeant. I'd play the Squire (or Villager) first, since it it goes better with Abusive Sergeant. Voidwalker is better at keeping our more valuable minions alive and more resilient to AoE effects, which is usually more valuable a bit later on. 

Turns 2 and 3:

Unlike a lot of other decks, we are not looking to play a 2-drop on turn 2, but two 1-drops. This is a crucial concept to understand that many players new to Zoo do not know about. The three 2-drops Zoo runs, Dark Peddler, Dire Wolf Alpha, and Knife Juggler, do not help us too much to contest the board early on since they only have 2/2 bodies. What the 2-drops do is boost our other cards, which makes them much more useful from around turn 4 onward. This doesn't mean that you never play these on turn 2, but as a general rule, avoid it. Acidic Swamp Ooze is usually only kept to react to a weapon, but is a fine turn 2 play against weapon-less classes such as Mage. 

Turn 3, then, is the moment we would like to play one of our 3-drops, Imp Gang Boss or Darkshire Councilman. So the ideal Zoo progression is as follows:

Turn 1: 1-drop

Turn 2: two 1-drops (or Coin 3-drop)

Turn 3: 3-drop

That's also a reason why the deck is so heavy on 1-drops, as it allows us to reach this progression more consistently, with another reason being that we want to get as much value from Doomguard as possible. Of course, this doesn't mean that we play like this every game. Sometimes we simply don't get the cards, and sometimes we have to react to the board and play differently. You'll sometimes end up playing a 2-drop on turn 2, even if you have two 1-drops in your hand. But in an ideal world, this is how we build the board fast.

Mid + late game strategy

If you came out of the early game controlling the board, there comes a point where you want to start hitting face. It is hard to give a general guideline as to when that is, but if you think that you can set up lethal the following turn you should usually go for it. 

- Doomguard is ideally played around turn 7 or so after you've managed to empty your hand. It is most often used to claim the board, but can sometimes be your finisher as well. Don't be afraid to play it early if you've lost the board, either. It may not work out that often, but not playing it will work even less. You also don't want to hold on to your Doomguard for too long, since the chances that you draw the 2nd Doomguard increase every turn. Remember that this is the star of the deck, so get him on the board.

- Sometimes you'll have to play Dark Iron Dwarf/Gormok the Impaler without buffing anything, just to get a body on the board. Just like with the Abusive Sergeant, you'd like to avoid this, but if you can't, don't be afraid to play the card just because you're missing out on the battlecry. The same is true for Defender of Argus, though there's hardly ever a situation where you want to play him on an empty board -- at least have him buff one minion that uses the extra 1/1 to clear something.

- Part of the reason why you want to hold on to your 2-drops for a little longer is that they get much better when the game is more developed. Dire Wolf Alpha is best when you have a bunch of minions on the board and you can trade them in such a way that all of them get buffed at some point. If you play Dark Peddler too early you might end up wishing that you'd taken another later on. Knife Juggler synergizes really well with Forbidden Ritual, a card that is in itself most powerful if its played on later turns. 

- Late game -- if you've made it this far and you're not close to delivering lethal, chances are that you're going to lose. Most decks have better late-game minions than this one, so you have to do well early on. If you're against another aggro deck, keep trading until you've blown them off the board.  

Zoo Positioning

The Image is taken from this incredible guide. 

Zoolock has many cheap minions that it relies on buffing, so board positioning is crucial in this deck. I will keep this section short and send you to this outstanding and in-depth guide instead. Just as a brief summary, here are some things to look for.

- There are two cards for which position is important, Dire Wolf Alpha and Defender of Argus. We always want to play with these cards in mind, even if we haven't drawn them yet.

- In general, the minions that die easiest go in the middle, while the minions that die hardest go to the outside. Note that this means that taunts also go in the middle, since they will generally be attacked first. Argent Squire and Possessed Villager go to the outside, since their shield/deathrattle will affect the conga line.

- Valuable minions such as Knife Juggler go furthest out, as we want to avoid trading them, if at all possible.

- We want our taunts to be next to Dire Wolf Alpha so they get buffed. We want Argent Squire to be buffed by Defender of Argus, since it basically gets the buff twice. Use Argus such that it helps our Minions to stay alive, e.g. buff 1 health Minions against Druid to make the board more resilient against Swipe.

- If possible, we want to buff our minions such that we have a 1-attack minion, a 2-attack minion, a 3-attack minion, and so on. This usually allows for the most efficient trades. This is also why we don't simply go left-to-right with out big-to-weak minions but put some of the stronger minions on the right side, as well. 

All cards explained?

Since this has already been done before and I find it a bit tedious, I'm skipping this section. I've already gone over a lot of cards in other sections as well. If you really want this, take a look WingsofWax's great Zoo guide. I would recommend the list and Mulligan strategy in the present guide, however, as I feel that they are more suited to the current meta. Let me know if you have any specific questions and I'll do my best to answer them. 

Mulligan

General Mulligan Guidelines

The mulligan is crucial for Zoo, as it is for any deck. We are generally looking to play 3 1-drops on the first two turns, so if you don't have any, it is often correct to mulligan all offered cards. With the coin, it is often correct to keep a 3-drop, looking to play it on turn 2. The following are general guidelines. Keep in mind that these will sometimes be contradicted by the class-specific mulligan suggestions later on.

- Flame Imp, Possessed Villager, Argent Squire, Voidwalker: You will usually keep all of them. An exception could be against a Warrior, on Coin, if you have all of them. Ditching 2, looking for an Acidic Swamp Ooze or 3-drop, could be an option. Never ditch the Flame Imp, though. You will usually play the Squire before the Villager, as mentioned above.

- Abusive Sergeant: Kept if you already have one of your 1-attack 1-drops (Argent Squire, Voidwalker, Possessed Villager). Very useful to trade those guys into bigger minions and establish a 2/1 at the same time.

- Forbidden Ritual: always ditch this. You may have to play it as your 1-drop in aggressive matchups if you are left with no other choice.

- Power Overwhelming: As Wings_of_Flame points out here, keeping Power Overwhelming in combination with Flame Imp to deal with turn 2 Doomsayer can be a good idea if you strongly suspect that you're up against a control deck. You'll sometimes want to keep it against Druid or Shaman if you already have solid 1-drops to kill of their big minions/taunts.

- Acidic Swamp Ooze: Must-keep against Warrior and Shaman, also solid against Hunter (Eaglehorn Bow). I would only keep it with the Coin and 1-drops against the Hunter, though. You can keep it against non-weapon classes if you already have a good 1-drop and simply play it on turn 2. It is a better turn 2 play against non-weapon classes than your other 2-drops.

- 2-drops (Dark Peddler, Dire Wolf Alpha, Knife Juggler): Mostly ditch these. This contradicts what a lot of players do, especially with the Peddler. But these cards are better played from turn 3-4 onward, and the first turns are crucial for us to establish a board presence. Exceptions do exist.

- 3-drops: Usually ditched going first, but you'll typically keep one of them going second. We'll get to the details in the class-specific sections, but as a rule, Imp Gang Boss is better against aggro decks as it contests the board better. Darkshire Councilman is difficult to kill since he's got 5 HP, he'll often make the opponent use heavy removal. You can sometimes keep one of the 3-drops going first if you're up against a class that's not super aggressive.

- 4-drops and Doomguard: Run. Run and don't look back.

Matchup-specific Mulligan guide 

Druid

 Hunter

 Mage

 Paladin

 Priest

 Rogue

 Shaman

 Warlock

 Warrior

That's it for now. I hope that you learned something if you made it this far! If you spotted any mistakes, you disagree with anything or you have suggestions on how to improve this guide, I'd love to hear about it. This includes recommendations on top Zoo streamers or written guides, I'm always looking to learn more.