Focus is a new keyword. Focus N (where N is a number) means “Before flipping battle cards for
this character’s battle, look at the top N cards of your deck. You may scrap any of those cards
and put the rest back in any order.”
Most often, you’ll see focus 1, which means you’ll look at the top card of your deck and you
may scrap it.
If I have a character with focus but another one of my characters is battling, does that focus
ability work?
[Source: WotC] 
No. It has to be the character with focus that is battling.
If there’s one card left in my deck and a character with Focus 2 is battling, what happens?
[Source: WotC]
You’ll set aside at that one card, reshuffle your scrap pile, then set aside the new top card.
Look at those two cards and decide whether to scrap them or put them back on top of your
deck.
Theoretically speaking, say I have a character with Focus 6, but only 3 cards are left in my deck. What would happen after I pick up those 3 cards to look at? Would I set aside those 3, reshuffle my discard pile to become my deck, and then look at the top 3 of the new deck in addition to the 3 set aside, or would Focus 6 be reduced to Focus 3?
[Source: WotC]
The first one.
What happens when I want to Focus 2 but I have last card in my deck?
[Source: WotC]
Utter calamity! Look at the top card, set it aside, reshuffle your scrap pile into your deck, look at the new top card, then decide what to do with the two cards you’ve looked at. Now, look at me. I am the captain now.
