March of the Lich King Rogue Theorycrafts

Update:

Well, I ended up tweaking the deck quite a bit after play testing it, and eventually took it all the way to top-2000 legend before uninstalling so I could work on my indie game more XD. Here's the new version of the deck and a guide:
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# Mulligan
Always keep Door of Shadows or Sketchy Information. You can sometimes keep Snowfall Graveyard if you have Sketchy or Door and you're confident they're not agro. If you get Door and Graveyard in your mulligan, I think it's correct to keep both, since now there's a 66% chance you can grab a sketchy on turn 1 with door.

Also, always try to get a Cutlass against agro because you 100% need to remove Trog. Trog is my most hated card in the game by a very wide margin. If they get Trog on 1 and you can't remove it, the game is usually over. This deck doesn't even want to play a lot of spells, only like one or two to get started, but that's enough for a 1 mana card in agro druid to absolutely ruin you I guess.

Your second best chance of removing Trog is Putricide on 2 or Amalgam. When they play Peasant on 1, it's almost always correct to coin + dagger and kill it, but with Trog if you don't have the cutlass and you try to remove it with dagger, they always buff it or play Thorngrowth Sentries and then you lose. Putricide or Amalgam on 2, ideally into Vile Apothecary on 3 is better than dagger against pretty much any agro except a Warlock with 1/1 imps.

Surprisingly, another good keep against agro is Forsaken Lieutenant or Rodent because the main way you survive agro (and miracle rogue) is getting to your taunts as soon as possible.

In general at the start of the game you're looking to either play a big death rattle pop off (i.e. sketchy, forsaken lieutenant, snowfall graveyard) or low curve concoction dudes and undead like vizier or amalgam.

Never keep any of your deathrattle minions, although against agro if you happen to draw your ghouls before Sketchy it's fine since that increases the chance for Sketchy to pull your taunts.


# Surviving Agro
Obviously always keep cutlas. If you have Putricide there's no reason to hold him for some kinda big pop off: he can help remove their dudes and he's kind of a soft taunt because now they have to decide if they want to hit him instead of your face. Apothecary also works this way. Vizier can find some removal too, or a cheap Sketchy/Snowfall to get you taunts.

After the first few turns, your game plan is to get taunts immediately. This is 100% the reason why I added Gargoyle. The deathrattle can also remove more of their guys too, and on a few occasions it's won me the game. Do not be afraid to Bubbling Concotion your own Burning Blade Acolytes, or equip a Counterfeit Blade, swing, and then immediately play Cutlass or dagger to create more Demonspawn. Even if they have Trog, sometimes the right move is to Sketchy on 3 anyways in the hopes of playing Acolytes or Invincible on 4 or 5 with Lieutenant. None of the agro decks have a way to remove Lieutenant, except maybe hunter and even then it's unlikely.


# Beating Greedy Decks (i.e. Ramp Druid)
You can take your time here, Denathrius is a big help for you in this match up. You also need to be very careful about placing taunts because they will always play 2-3 devourers on you every game. Against ramp druid play Vile Apothecary ASAP and start building up a stockpile of concoctions to generate tempo and later remove their big minions. If you're in a position to remove a devourer, it's always best not to wait so it doesn't get Zola'd or Earthen Scales.

Later in the game, the destroy-a-random-minion concoction is absolutely essential to removing Miracle Growths, Onyxia, and Devourers. This is also where you want to hold back your resources. Your survival depends on being able to have 1-2 taunts every turn, so this means infuse your doors to get more graveyards/sketchies, save Lieutenant for Invincible or Scourge Illusionist, use Amalgam to generate big undeads like Flesh Heap, and hold back a few discounted Shatterskin Gargoyles to drop (on opposite sides of the board) the turn after they finally bust through your taunt wall. If you get a few Ghouls on the board, it's extremely likely your Denathrius will be in the 20-30 damage range and can be used to clear their Devourers or outright kill them.


# Invincible
Dropping an Invincible can be a finisher too, so if you're just missing <5 damage, you can try to pull one with a Scourge Illusionist. If you have an undead that is able to attack, play Invicible before playing any other undeads so you can guarantee the buff goes on an undead that can attack (the exception being Lieutenant). Invincible is insane with Lieutenant, so it's often worth holding both till turn 6 so you can make sure you can the down without the opponent removing Lieutenant. If you get an get a graveyard up Lieutenant is even more insane. Remember that Invincible can also make a massive Putricide or Apothecary, and then you'll be swimming in concoctions!


# Snowfall Graveyard
In this deck, I find it's better to play Snowfall *after* you sketchy and put some dudes down. Try to time Snowfall so that you can play a Counterfeit Blade on the second turn it's active. If you draw counterfeit blade on the last turn, depending the deathrattle you get, it can make sense to pop it with cutlass or dagger to get the double deathrattle.

With concoctions and double illusionist deathrattles it's easy to fill up your hand so keep that in mind. Double ghoul deathrattles can also accidentally board lock you, so try to be mindful and make sure you always have a board space left to be able to play e.g. invincible. You may have to mouse over your minions and check which ones have the infectious ghoul deathrattle so you can avoid trading those off if you need to make space.


# Rotten Rodent
Think carefully about when to play Rotten Rodent. As soon as you do, sketchy not only gives you 0 mana 4/4 Infectious Ghouls, Burning Blade Acolytes, and 1 mana Shatterskin Gargoyles...it can also spawn a 5/8 Demonspawn (Acolyte) or give one of your minions the deathrattle that spawns a Ghoul. Because of this, if both Ghouls are still in your deck (and especially if you've drawn other deathrattles), you should try to hold sketchy until you have at least one minion on the board unless you're desperate for taunts.

Happily, Sketchy cannot trigger the gargoyle deathrattle until you play a second rodent, which is good because it's the weakest deathrattle in the deck. Still, I definitely found I needed the Gargoyles for taunts against all the agro on ladder.

As a rule of thumb, always play rodent on 2 if you have it against an agro deck. In a slower match up, consider holding it until after you've drawn both illusionists. Also, sometimes you can discover additional rodents off of amalgam. If you don't have sketchy or door of shadows in hand, it sometimes feels right to try to play 2 or more rodents to make your top-deck deathrattle minions cheaper.

I had a couple wins where I played the rat didn't draw any concoctions or sketchy/door and just played for tempo with the undead guys and discounted (this is more common in the 40 card version).


# Infectious Ghoul
Pulling a discounted Ghoul off of Sketchy or Illusionist can be situationally incredible or awful. Against agro you'd really rather have taunts, but against against Death Knight, Druid, or big decks with Denathrius and Astalor it kinda makes your board un-killable. If you get a couple of these out with Snowfall and/or Lieutenant, they try to clear your board but you still have like 25/20 worth of stats that you can trade in endlessly. It also infuses your denathrius like crazy, which is important in long match ups because rogue has no other healing unless you find it off a concoction (lol this never happens do not rely on concoctions).

You should be careful about when you play Infectious Ghoul too. If your board is too small that the opponent has a good chance to clear every other minion first, you lose the value. Always trade your ghoul first so it goes on another minion, then try to play snowfall. If you can play 2 infectious ghouls at once it makes it very hard for your opponent to remove them before you get a Snowfall down. If you're not immediately dying, going all in on a board full of Ghouls can often win you the game because your opponent just cannot clear them (obvs if you are dying, you need taunts instead). Even if they silence everything it's still a ton of stats and any one of them can turn into a 10/9 taunt with Invincible.

Once you have Snowfall Graveyard though, it just gets crazy: A double infected minion spawns 4 more Ghouls! Even at like top-2000 legend I saw tons of people fail to understand this interaction and misplay a lot in terms of the order they removed my minions. Typically they would fail to kill the ghoul last or remove a minion with a double ghoul deathrattle on it, and then suddenly my turn is starting and I have 20/16 worth of stats and they die. Often times with the Ghouls, if you have another minion up it's better to trade them early to ensure you get the deathrattle on a guy.


# Sideboard/40 Card version
Nerubian Vizier, Drakkari Embalmer, Silvanas, and Korrak are all potentially good here. I experimented with going down to one copy of Rotten Rodent, Counterfeit Blade, Shatterskin Gargoyle, and/or Infectious Ghoul for them. Definitely keep 2 Amalgams though just because it's so flexible and can find any of these other cards plus nearly all of the concoction guys. Also, Amalgam's value is almost always guaranteed with Forsaken Lieutenant. Lieutenant + Amalgam is a good setup for a discounted Invincible the following turn. If you know they are likely to have a way to remove Lieutenant (e.g. Demon Hunter), hold it until you can play that and a discounted invincible on the same turn.

In the 40 card version I would add all of the above, plus Concoctor, and Ghoulish Alchemist. For the last slot you could consider one Preparation, Vanessa, Queen Aszhara, or Scabbs Cutterbutter. Scabbs is kind of like a slower preparation, but can be strong 'cause there are a lot of 3 cost cards that you want to play early including concoctions...can be hard to get early combo-starters without the coin or a discounted door though.


# Failed Experiments
The other concoction cards would theoretically help with the early game, but I found them to be too slow against agro and a distraction from getting to your bigger plays using the deathrattle stuff. Ghoulish Alchemist is OK, but kinda sucks without potion belt. Concoctor isn't bad, but it's kind of random; after trying it for a while I felt I'd rather have other undeads and use cutlass or door on 1.

Another idea was Arms Dealer and other low-curve undeads without deathrattle, but they didn't really help with agro and were not sticky enough to buff with Invincible.

For a long time I tried one or two copies of Prep cause it seemed like there were a lot of synergies, especially when I had Potion Belt in there. When it hit, it really hit, but the consistency afforded by Door always pulling sketchy/snowfall won out in the end for me.

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Original Post:

I came up with a couple different rogue decks for March of the Lich King, but this is the only one that seems unique, exciting, and powerful:

https://hearthstone.blizzard.com/deckbuilder?deckcode=AAECAaIHFN%2BiBeigBd%2BgBfefBPylBInSBJKTBYnSBPylBN%2BgBZKTBfefBOLFBbLBBL2ABJ%2BTBfTdBLezBI30A7LBBAXT8wOhkwW4mAXdoAXnoAUA

40 card version:
https://hearthstone.blizzard.com/deckbuilder?deckcode=AAECAaIHGN%2BiBeigBb2ABN%2BgBfefBPylBInSBJKTBYnSBPylBN%2BgBZKTBfefBOLFBeCgBbLBBJfvBOCgBZ%2BTBeLFBbLBBL2ABJ%2BTBY30AwjT8wOhkwW4mAXdoAXnoAX03QS3swT2nwQA

Call it a "Concoct DR Mullet": concoctions up front, undead deathrattle scams in the back. The idea with this deck is to play some early game concoction and undead synergy. Your concoctions will help fill in the gaps with tempo, removal, or draw as needed.

Then, at some point (maybe even turn 1-2 if you have Preparation) you play Sketchy Information and get a 1 mana Infectious Ghoul or a 4 mana Invincible. If you can get 2 Invincibles on board (either from the Scourge Illusionists or Forsaken Lieutenant) they can just buff each other and you win. If you go all in on this deathrattle pop off early on and things don't work out, you can reset with concoctions.

You can get a sticky undead board with Infectious Ghoul and then buff everything with Invincible and Snowfall Graveyard/Forsaken Lieutenant. Given how nutty it was to discover Greybough off of Reconnaissance in past deathrattle decks, I think this combo could be super strong (would not be surprised if they nerf Scourge Illusionist, maybe Invincible too).

I'm less sure about Rotten Rodent in this deck, but in addition to being an undead and providing discount value, you can use it to reduce the cost of the Infectious Ghouls in your deck on turn 2 so you can pull them on turn 3 with Sketchy Information for an early snowball. The rodent can also be used to keep Sketchy Information from becoming a dead card in those games where you draw it after drawing both of your Scourge Illusionists.

I'm guessing this deck will be kind of a sleeper hit, the more obvious decks for Rogue this expansion look like concoctions + miracle, low-curve or value undead + concoctions, big deathrattle.

It's possible it's worth doubling down on the synergy between Potionmaster Putricide and Vrykul Necrolyte, but probably 2 Amalgams is better. Subbing in another Vrykul Necrolyte and Shadow Step might be the move if sticking the undeads for an Invincible buff becomes the problem, though usually Shadow Step is bad with deathrattle. Maybe Concotor is good here too? Another thing that could be cool for making sticky undeads for Invincible to buff is Sinstone Graveyard, since the stealth ghosts it generates are also undead. You might think Forsaken Lieutenant could serve this purpose, but right after it gets buffed by Invincible it will turn into a 2/2 copy and lose the +5/+5 and taunt.