CURRENT GWENT DECK - DISREGARD ALL PREVIOUS (the last one is still okay-ish but not as good as this one)
Gwent keeps changing again and again. I guess that's to be expected for a game still technically in "beta" (though I'm beginning to wonder if it ever won't be in beta). As the great nerf-buff bat swings wildly, we must keep up with the changing times.
After trying many, many, MANY netdecks from gwentDB, over and over again, I've determined that all of them are just too damn gimmicky for me, depending heavily on very precise, lucky draws and exact plays that can be countered by an opponent who knows what to expect. I've had much better luck with a deck mostly of my own making:
Ithlinne Aegli <-- Since Tremors got nerfed, I no longer save Ithlinne for a final nuke. She's best played early-ish to remove enemy "engines" that generate value over time.
Iorveth: Meditation <-- He got nerfed pretty hard recently, so he's much more situational now. Feel free to play him early if you see a good opportunity, as he might end up being useless if you save him too long.
Isengrim: Outlaw <-- Use him to pull Decoy or Commander's Horn if you have a really good use for them. If you have them both in hand, then instead spawn the most useful silver card you can.
Commander's Horn <-- Could possibly be replaced with a stronger Silver, since it got nerfed recently, but it still serves pretty admirably for me.
Vrihedd Dragoon x2
Hawker Smuggler x2
Dwarven Mercenary x2 <-- I run these guys because running only 1 type of dwarf besides Agitator is too risky, and the Mercenary can pull allies out of weather, which is nice.
Dwarven Skirmisher x2
Dwarven Agitator x2
Elven Scout x2
Alzur's Thunder x2 <-- Always keep one of these in your deck (NOT your hand) so that Ithlinne can summon it.
This deck is based around Ciri: Nova, a card that strengthens herself from 1 to 22 when played if you have exactly 2 copies of each Bronze card in your deck. No more, no less. She's your trump card, ideally played last, to avoid scorch.
Remember, any cards you swap during your mulligan are "blacklisted", meaning you will not re-draw a copy of that card. Here is your blacklist order: Alzur's Thunder (need to keep one in your deck for Ithlinne), Dwarven Skirmisher & Dwarven Mercenary (both work best when drawn by other dwarves).
Ideally, you want to have 1 Wardancer and Yaevinn in hand. That way, you have an excellent card for round 2 whether you win or lose.
If you draw 2 Wardancers, feel free to mulligan 1 of them. But you can always do it later with your leader, Francesca.
You'll usually want to open with a value engine, like Vrihedd Dragoon or Hawker Smuggler. The latter is extremely good against swarm decks that play tons of little units, including mirror matches against Scoia'tael.
Always try to play a dwarf in round 1, so that Paulie Dahlberg will have something to resurrect in round 3. Playing Barclay Els in round 1 is ideal, so he can be resurrected by Hattori in round 3 and so Paulie can resurrect the dwarf that Barclay strengthens. But just remember that if you don't have Paulie in hand, Barclay could pull Paulie, so only risk this if you have a dead dwarf soldier in the graveyard for Paulie to rez.
If by some freak chance you have no Dwarven Agitators or Barclay in hand, at least play an Elven Scout so that there's something for Hattori to resurrect in round 3. If your Elven Scout can spawn a hand-buff card, always buff Hattori.
If round 1 is about to end and you're losing, make sure you have a Wardancer in hand. If you don't, then play Francesca and draw one.
If round 1 is about to end and you're winning, make sure you have Yaevinn in hand. If you don't, then play Francesca and draw him.
If you have both in hand, feel free to save Francesca for round 2 or 3 for extra hand control.
This round tends to be short, since the winning player will usually "dry pass" without playing a card, depending on who has more cards, either to force the enemy to go down a card, or to even out the cards if they're behind.
If you lost round 1, mulligan your Wardancer immediately to avoid going down a card if your opponent dry-passes. Then play normally and try to stay ahead in score until your opponent passes.
If you won round 1 and your opponent passed early, so you both have a lot of cards still in hand, start playing normally in order to bleed him down, while saving your best cards for round 3. Once you've bled the enemy enough, play your Yaevinn. This will force your opponent to play another card, and hopefully you can stay ahead.
If you still have Francesca, play her at any time to swap out your most useless card (possibly a Wardancer or Yaevinn if you still have either of them) and draw Ciri: Nova or the next best card.
Then just play normally and drop Ciri last and hope you win!
This deck is nowhere near as powerful as it was before the Squirrels got smacked with the nerf stick, but I still have way, way more luck with it than any other supposedly stronger decks I've tried.