Hearthpwn

i've always been a fan of the secret mage archetype, and after doing a bit of experimentation this is the final form of my personal wild secret mage that i use on ladder

i've been working on this deck since MSoG and this is the version that works the best over a large amount of games

Variations:
 if you don't have certain cards or you don't like certain cards in the deck some cards that can also work can include

 Primordial Glyph - this card is high tempo and can fish you out an answer in a sticky situation
 medive's valet - this card isn't in the list mostly because i don't have it yet, but this being secret-oriented is a perfect fit for a secret mage
 Frostbolt - frostbolt is a fairly well balanced burn card that can help in a lot of situations 
 Unstable Portal - this card being very tempo-oriented can get some extra board presence out at a discount
 arcane intelect - while it is a tempo loss, a 1 off intellect can help re-fuel when you're running low on steam
 More secrets - obviously in a secret deck, secrets are the core synergy of the deck, and provide tempo and play mind games with the opponent
 2nd Polymorph - polymorph is a hard removal, and a second copy can improve your winrate against control at a cost of winrate against agro
 cabalist's tomb  - similar to polymorph, increases winrate against control at the cost of agro winrate
 tech cards - if you notice yourself running into a particular deck a lot, why not tech against it? throw in a hungry crab for murlocs!, or an ooze for weapons!

Instructions:

 Mulligan
  in all situations you want to mulligan away any cards that cost 4 or more except etherial arcanist

Against control:
  when you play against control your value cards are your best friend, you want to try to get the highest value spells off of etherial conjurer, best case scenario cabalist's tomb and you need to be very greedy with your secrets, trying to get Effigy off on a 5 or 6 mana minion, duplicate on Etherial conjurer, getting high cost cards off of Mirror Entity, and Mana Bind and take out their big threats with Polymorph

Against agro:
  when you play against an agressive deck you want to go full tempo, get as many secrets out there at once, take over the board with massively buffed etherial arcansts get full value from your 0 mana Kabal Crystal Runner, if they get too far ahead use a Flamestrike and wipe them out, ideal targets for secrets are things that can get you more tempo imidiately, Effigy or Duplicate on your crystal runners, or etherial arcanists, and use your Fireball as a finisher

General tips:
 in this deck there are enough secrets that they can actually be secret - so that being said, don't play secrets at obvious times, do not play mirror entity into an empty board, or effigy right after playing a big minion

remember secrets only activate on their turn - so it's ok to play an effigy if you have a 1 mana minion on the board as an example, just be sure to trade it off on your turn

preemptive secrets - if you know you're going to want a secret out with a specific minion, play it 1, 2 even 3 turns in advance, it makes it a lot less obvious and can still be controlled 
 (for example playing a counter spell on an empty board on turn 3 for an arcanist on turn 4)

don't over develop - at all times you need to keep in mind this deck has minimal card draw if you over use your resources you'll run out fast, kabal lackey and kabal crystal runner are the easiest to over extend with.

Etherial arcanists - Never put both etherial arcanists out at once this can make you vulnerable to losing them both very quickly, in a similar sense, play your first arcanist as soon as possible and try to get a Counterspell or Duplicate out with them, the later in the game you wait, the easier for them to be removed before they can grow, the best turn to play them is turn 4 or 5, when you have a reasonable amount of secrets out and you are most likely to keep them alive on the board

Weak matchups:
 Paladin - from my experience with this deck, paladins have an un-canny ability to ruin secret setups easier and cheaper than any other class, be careful around them

 Dragon priest - dragon priest has a strong early game from their dragon synergy cards combined with priest's control oriented spells, and have a massive number of large threats in the late game, they can out-value your secrets if you're not careful, the best time to beat them is in the mid-game before they can get their dragons out

Jade druid - even though this is a high tempo deck jade druids can ramp up and do what jade does best, so to effectively beat jade, you need to rush them down before they can get their jade counters above 5, after that the chances of winning decrease majorly

Zoolock - in the unlikely case you run up against this uncommon deck in our current meta (2017 Un-goro), the particular zoo cards used by warlock and their ability to re-create a board quickly from their boosted card draw can out-tempo this deck, for this match up you are almost guaranteed to need a flamestrike

Strong matchups:
 Jade Shaman/midrange Shaman - shamans can't establish their board presence quick enough to defend against this deck, and if they do manage to get a large threat such as their notorious 4 mana 7/7 from the old gods meta, they can usually be taken out from board trades or spells like polymorph

Pirate warrior (wild And standard version)- yes, you can out tempo the pirate warrior decks, especially after the nerfs to the small time buccaneer, you can destroy their pirates with the 5/5's you can usually get out fairly easily and stay alive from your ice barriers

Quest mage - the well known quest mage can have a difficult time keeping up with the high amount of temp produced by this deck, and suffers because of it.

Reno/kazakus decks - the sacrifice of having only a single copy of cards hits these decks hard with defending against secret mage, as most of their anti-agro cards are less effective against this deck, and some of their cards can be negated or used against them from your own secrets

Rogue - the rogue class simply doesn't have enough healing or effective answers to withstand this deck, and the only rogue deck that had a distinct advantage (quest rogue) has been nerfed, so rogues are in a bad spot against you

all other match ups are ether fairly even or i have not play-tested enough to have a reliable measure