A Pretty Panda
fuckin' called it, man
It's true that card games are inherently pretty random, in that you could have answers to everything in your deck but the problem being you have to draw them. What you need to do is apply some deductive reasoning using the information you're given. If you're playing a mage you know they're immediately locked into mage class specific and neutral cards and you know what the hero power is capable of. Next would being figuring on what type of class deck they have. Freeze mage typically has some different cards from a tempo mage, from there you can assume what the rest of their deck generally looks like based off that. Then you can count cards and stuff both from your deck and your opponent's, play around their stuff based on what you think they have etc etc.I am definitely not just throwing cards on the table and hoping for the best if that is your impression. However, without prior knowledge to what my opponents deck contains there is no conceivable way I can prepare for every outcome with only 30 cards, 3-4 of which are randomly on my hand at the start.
So if I play a Paladin deck, what can I possibly do against a Mage? I throw out smaller minions, she blasts them all with 1-2 damage spells that targets everything. I throw out larger minions. She kills them using big hard hitting spells or freezes. I throw out a mixed group, transmogrify-whatevs on the big ones and more spells that kills everything. I put shields on my minions, she JUST happens to have a card that absorbs all divine shields specifically and buffs it to a 9/9, how can I possibly be ready for something like that!? Out of 9 different classes, a billion different combinations of decks, there is no way I can prepare for shit like that. My strongest spell card at that point does 3 direct damage to a single target, where summoning minions, trying to protect them to live for just one round just gets them murder fucked instantly.
I feel like most skill in card games comes from background information so just play a lot
That's not to say there's no dumbass luck RNG in the game but you can do basic card game things to at least try to mitigate it