Most assimilate folks I meet like to pass straight away early on in round 1, thinking it’s convention not to waste your good cards, and the other player will dry pass into R3.
I say fuck that strategy, you’ll nearly always win if you bleed round 2+ leader at the last card
Scenario 1: Opponent uses leader ability as you’re bleeding, to ensure card advantage. Then, going into round 3, even though you have 1 less card, you make up for it with a free double cross pick of opponents best card, often times it’s a free braathens or artaud
Scenario 2: opponent saves leader, thinking they’ll get away with it to save for round 3. Then, when you play your last card, use leader on their last 2, and you’ll get a free Artaud or braathens they’re saving for R3, and it’s too late for them to leader you back.
I find scenario 2 happens 90% of the time. Opponent never expects you to go all in, then once you play last card, they don’t have a double cross target, and will not catch up
Win round 1, bleed round 2, if opponent double crosses, pass, and if opponent saves leader ability, use yours on last card so he has nothing to catch up with. Ez mirror wins. I actually can’t recall losing with this.
Source: https://www.reddit.com/r/gwent/comments/sa8msx/theory_in_assimilate_mirror_youll_win_virtually/
