If it's more or less than 20, nothing is destroyed
The randomness that comes with opening packs might mean more or less depending on the box, and extra mythics can be pulled in The List and wildcard slots, though at a much lower rate
A Lotus Bloom, Ad Nauseam, Angels Grace kill on Turn 4 costs six mana, but you have three from the Lotus Bloom and four land drops
I could deal with just about anything that was thrown at me, but had trouble winning even once I got into an advantaged position
When Sharp-Eyed Rookie's ability tries to resolve, the other creature's power is greater, so you'll put a +1/+1 counter on Sharp-Eyed Rookie and investigate
My favorite Squirrel trick in red is Book Burning, which solves that pesky threshold problem