Quick guides is a series of articles that are mostly aimed at new/intermediate players. Goal of those guides is to explain common terms, strategies etc. in a concise and understandable manner. If you're looking for more in-depth guides, deck lists etc. - check out other articles on the site!
First article is about tech cards. What are those, why should you use them and what are the most popular tech cards in the current meta.
What Is A Tech Card
Tech card is a card that you wouldn't put into your deck in the vacuum (so not accounting for any outside factors). It's a card you put to counter specific meta or strategy that you often face. It doesn't necessarily have to synergize well with your deck - it just has to punish opponent for playing something. Basically any change in your deck that seemingly weakens your deck (if you don't look at the matchups), but increases your win percentage in certain matchup(s) is a tech card.
It's easiest to explain on example. One of the most basic tech cards is Acidic Swamp Ooze. While the card itself is weaker than most of the 2 mana minions when it comes to deck synergies (e.g. you'd prefer to play Sorcerer's Apprentice in Mage or King's Elekk in Hunter), it punishes opponents who play weapons against you. So if you face a lot of classes that commonly use weapons (e.g. Warrior, Rogue) - the card might turn out to be better than your normal 2 mana minion. It's a pretty extreme example, but destroying a Gorehowl that only swinged once means about 5-6 mana on top of a 3/2 body - and that's all for 2 mana, meaning it's a great value and tempo swing.
Remember that you have to tech in against specific decks. Tech cards usually lower your win rate against matchups they're bad in - following the last example, Acidic Swamp Ooze is a bad card against Priest or Mage, because they don't have access to weapons. So you can't just throw in every tech card possible and expect them to improve your win rate. Before using a tech card, you need to analyze the meta you're playing in - see what your most common matchups are and then adjust your deck accordingly.
Why And When Should(n't) You Tech
The most simple answer is - tech cards are important part of the deck building, they might boost some of your matchups significantly. But if they're used incorrectly they might lower your win rate instead of increasing it.
First thing that you need to take into account is frequency in which you face a certain deck. If let's say 40% of your matchups are Zoo Warlocks, then you definitely want to tech in against that deck. If it's 20%, then you might do that if a certain tech card isn't bad in other matchups (e.g. you might tech in Mind Control Tech, which is also great against Shaman). But if you face a certain matchup less than 10% of the time, I don't think it's worth to use tech cards at all.
When using tech cards that are good in more than one matchup, you should sum up the stats. E.g. if you want to tech in weapon destruction, instead of checking out how often you face Warrior, check how often you face any class that weapon destruction is good against.
Tracking your stats is a great thing to do if you consider using tech cards. Then you have a clear view of the meta you're playing in. You can also follow your gut feeling, but it might be wrong. For example, after TGT my friend really thought that Secret Paladin is about 50% of his matchups, but when I told him to track the stats it turned out that it was only about 25% (it was still a lot, but nowhere close to 50%).
Why You Shouldn't Netdeck Card For Card
For those not familiar with a term, netdecking means copying someone else's deck and playing it instead of creating a deck yourself. People usually copy the decks of high ranked / pro players, because they are generally much better at deck building.
I'm not against netdecking at all. Most of people do that, including best players. In fact, I post my decks here so you could copy and play them yourselves. So don't feel bad for doing that. You should, however, feel bad for copying a deck exactly card for card without giving it any thought.
It's about tech cards or maybe rather card choices in general. When a pro player is creating a deck, he tries to make one that is good in the meta he is facing, not IN GENERAL. Meta is different across the board - on different servers, ranks, time in the season etc. you face a different meta. While the decks you face might be similar, the frequency in which you face them might be completely different. And so, pro player might cut Unleash the Hounds from his Hunter deck, because he might not face enough flood decks to justify it. But someone on rank 10 might face A LOT of flood decks. In that case, copying a deck card for card and not including Unleash might be a terrible choice and the "pro deck" might be much worse than the one you would make yourself.
Another thing is that a lot of the decks you see online are tournament decks. Tournament meta is way different from the one you face on the ladder, especially if you can ban one deck from the opponent. While tournament decks might work on the ladder, the tech choices are usually not optimal and you should generally stay away from them if you want to play on the ladder.
I don't say that you shouldn't copy the decks at all - they're usually great and should work well for you. But, don't be afraid to change a deck that got to rank 1 Legend or won DreamHack. It doesn't mean that the deck is perfect, it just means that it was good in a specific meta that very likely might not be the one you're playing in. Giving the Hunter example again - a lot of pro players were cutting Savannah Highmane in favor of Stranglethorn Tiger in their tournament decks to counter Miracle Rogue (Sap is much worse against Tiger than against Highmane). While it's a great choice against Miracle Rogues, unless you face a lot of them on the ladder (which isn't likely if you're at lower ranks) it's not a good choice. So in that case, giving the choice a second thought and changing it back would be the good decision.
Remember that tech cards that are used in a wrong way decrease your win rate instead of increasing it. So if you play a deck with tech cards, be sure that they actually work against the opponents you are facing. If you're not sure, you're a new player and you can't really analyze the meta, it might be good idea to stay away from tech cards in general. "Vanilla" deck with no techs might even be a more solid choice for low ranked ladder climbing.
Popular Tech Choices
Here are some of the tech choices that you might find useful in the current meta. It's not all of them, because it's simply impossible to list all the possible tech cards. We have A LOT of tech cards in Hearthstone and most of them aren't used or barely see any play, because the meta isn't right. For example, something like Hungry Crab could become a very common tech card in the future, if Murloc decks were popular in the meta, but that's obviously not the case right now. So I'll stick to the ones that are commonly seen and are strong in the current, WoG meta.
Weapon destruction is probably the most common tech in the current meta. A lot of top tier decks are weapon decks and destroying them interferes heavily with the deck's game plan, while usually netting you a lot of value. There are two possible cards in this category - Acidic Swamp Ooze and Harrison Jones. Ooze is a higher tempo card, you put it into the decks that don't want to play slower cards or just don't need more value. So, you might play Ooze over Harrison in decks like Zoo Warlock or RenoLock. Then, Harrison is usually played in the decks that can afford to play slower cards, need more card draw or generally prefer value over tempo. E.g. Control Warrior or Ramp Druid. There are some decks in which those are interchangeable - for example, I've seen both of them being played in Control Paladin. Ooze is also - obviously - a budget choice. If you don't own Harrison and don't want to spend 1600 dust crafting it, Ooze should do similar job even in decks like Control Warrior.
Silence has fallen out of favor with the nerf to Ironbeak Owl and with a lot of the Deathrattle cards gone in Standard. Before WoG, pretty much every deck used some strong Silence targets. In the current meta there are less of them, but you can usually still get some Silence value. You can tech it in if you face a lot of N'Zoth, the Corruptor decks or decks running the big Deathrattles in general - so cards like Cairne Bloodhoof, Sylvanas Windrunner or Tirion Fordring - Silence is amazing against those. You can also play Silence in faster decks if you face a lot of heavy-Taunt decks, e.g. Ramp Druids (Silence is amazing against Ancient of War).
When it comes to neutral Silence choices, we have Ironbeak Owl and Spellbreaker. Spellbreaker is almost universally better than Owl, because for just 1 more mana you get +2/+2 in stats and the effect is exactly the same. Owl might still be prefered in Hunter for the sake of Beast synergies. There are also some class choices - Keeper of The Grove, although nerfed, might still compete with Spellbreaker (it's better against faster decks, but worse against slower) and Aggro Shamans might play Earth Shock for a cheap Silence to easily get through the Taunts.
Doomsayer was always used in slow Mage lists because of the possible combo with Frost Nova. But since WoG, it has been ran in a lot of different decks. The biggest reason was the Shaman's popularity and how strong their openings might be. With a great opening, they're nearly unstoppable. But if you play turn 2 Doomsayer and it goes off, you're usually a favorite to win - not only you've most likely killed something, but also you denied their turn 2/3 play. Doomsayer is also amazing against other heavy tempo decks like Zoo Warlock or Pirate Warrior, where stopping their early game is very important.
You usually want to play Doomsayer in reactive decks, that don't mind skipping turn 2 anyway - Control Warrior/Priest/Paladin, RenoLock, maybe even slow Druid lists. You can also play it in the deck with strong turn 3 that wants to guarantee the tempo move - like Midrange Hunter, that wants to drop a t3 Beast on empty board and follow it up with Houndmaster.
Stampeding Kodo is a very popular tech choice in the current meta. As it turns out, we have A LOT of 2 or less attack minions that are commonly played. While it gets most value against Midrange/Tempo Warrior (Bloodhoof Brave, Frothing Berserker, Acolyte of Pain, Armorsmith), it's also good against e.g. Shaman, Zoo Warlock and Hunter. Argent Squire is a very popular 1-drop (and sometimes hard to get rid of, Kodo can one-shot it), Flame Juggler is one of the most popular 2-drops and it's right in the range of a Kodo (clearing a 2/3 for free isn't bad at all). It might also be seen as a kind of a counter to the previous tech card I've listed - if enemy decides to play a tempo Doomsayer after a board clear, Kodo can deny him the board initiative. It's generally a strong tech right now, mostly seen in Midrange or Control lists.
Big Game Hunter
Big Game Hunter is much less common than it was pre-WoG. At 3 mana it was broken, but at 5 mana it's actually a balanced tech card. You don't just throw him into most of the decks, but only if you face heavy 7+ attack minions meta or you play a deck that is very low on removals. You might still play Big Game Hunter in slower Druid lists (no hard single target removal besides Mulch) or RenoLock (no hard single target removal besides Siphon Soul), especially if you face a lot of Shamans running Flamewreathed Faceless (it's possibly the best on-curve answer), slower decks that play e.g. Ragnaros the Firelord or Giants (Mountain Giant is quite common in RenoLock while Sea Giant is seen in Zoo). BGH is also surprisingly good against Miracle Rogue, as an answer to a big Edwin VanCleef or minion buffed by Cold Blood.
- The Black Knight - With Sludge Belcher gone and no card to take its place, there are much less big Taunts in the meta. It still might be a good tech choice if you face a lot of Druids.
- Baron Geddon/Chillmaw/Corrupted Seer - Tech choices against flood decks. Baron Geddon and Corrupted Seer are a more general ones, while Chillmaw might be used in the decks that also run Dragons. Most of the classes have their own ways to deal with flood decks, but if that's not enough, you might play one of those on top of that - e.g. Baron Geddon is quite common in Control Warrior and occasionally seen in Druid.
- Crazed Alchemist - Used by Zoo, mostly as a tech against a tech (Doomsayer). It's also good against other high health, low attack targets like Bloodhoof Brave, Armorsmith or Darkshire Councilman. Sometimes it might be used just as a way to deal 1-2 damage or make your minion survive the trade. I've seen some other fast decks running it too, but very rarely.
- Mind Control Tech - Another tech card against flood decks like Zoo or Shaman, might be used by the decks that need an earlier comeback mechanic than turn 6/7 (Geddon & the rest), don't want to fall behind on the board in the mid game or just don't want to AoE their own board too.
That's all folks. I hope that some of you have learned a thing or two about tech cards. I probably haven't covered everything, but I've tried to keep it short for to not overwhelm novice players with too much information at the same time. If you still have any questions, feel free to ask in the comment section below.
If you want to be up to date with my articles, you can follow me on Twitter.
Good luck on the ladder and until next time!