Before you attack, put them on a hand: work out what cards they could be holding. Four clues:
Their Legend's Domains. They can only play cards of those Domains.
Cards you've seen. Check their trash. A card played once may have a second copy.
Cards in hand. An empty hand has no tricks.
Runes left ready. Count the Power they make. A tapped rune can still be recycled for Power of its Domain, but it gives no Energy.
Punch First: Action[Action], +5 Might this turn. Sett with [Body][Body] open and cards in hand? Expect it.
Lord Broadmane: Ambush[Ambush]. An answer you can hold until they show their trick.
Then play around it. Send enough Might to win anyway. Make every fight bait and hold your Ambush[Ambush] until they show the trick. Or take the empty battlefield instead.
Don't play around a card they can't pay for, one they'd have used already, or one that doesn't stop you winning. And an attack that makes no sense, like a 2 into a 3, means a trick.
Quick check
Sett attacks your 3-Might unit with a 2-Might unit. He has [Body][Body] open and 2 cards. What does it tell you?
Predict
Sett has 2 cards, a Punch First in his trash, one Body rune and one Order rune ready, and two Order runes tapped. Can he pay for Punch First (1 Energy + [Body][Body])?
You're on 7 and B is already scored: take A and you win. Sett (Body/Order) holds A with a Vanguard Sergeant (4). He has 2 cards in hand and two Body runes ready, and you saw him play Punch First (Action[Action], 1 Energy + [Body][Body]: +5 Might this turn) two turns ago. Your Direwing (7) and Kinkou Initiate (3) are ready.
Need a hint?
Send the Direwing and the Initiate to A together: 10 still wins if the Sergeant becomes 9.
You're on 6: take A and B to win. Sett's Vanguard Sergeant (4) holds A and his Pit Rookie (2) holds B. He kept [Body][Body] open with 2 cards in hand, and there's a Punch First in his trash. Your Direwing (7) and Kinkou Initiate (3) are ready, and you hold Lord Broadmane (Ambush[Ambush], 5 Might) with exactly the runes to pay for him. He can only Punch one fight.
Need a hint?
Send the Initiate to B and pass, then the Direwing to A. Keep Broadmane until he plays Punch First, then play him into that fight.
It's Sett's turn: his Pit Rookie (2) is about to attack your Flame Chompers (3) at A. He has 2 cards in hand and two Body runes open; a Punch First is in his trash. You hold En Garde (1 Energy, Reaction[Reaction]: +1 Might, +1 more if it's alone) and Lord Broadmane (Ambush[Ambush], 5 Might), and your 5 Fury runes pay for En Garde (1 Energy) or Broadmane (5 Energy + [Fury]), not both. Keep A.
Need a hint?
Pass. If he plays Punch First, play Lord Broadmane to A.
You're on 6: take A and B to win. Sett's Vanguard Sergeant (4) holds A and his Pit Rookie (2) holds B. He has 2 cards and a Punch First (1 Energy + [Body][Body]) in his trash. His runes: one Body and one Order ready, two Order tapped. Your Direwing (7) and Kinkou Initiate (3) are ready.
Need a hint?
Direwing to A, the Initiate to B. He can't pay [Body][Body].
