If opponent has 0 cards in hand at the beginning of their turn they do not take the 20 damage from The Rack, presumably because the initial text that “increases opponent’s cards’ cost by 1” is failing due to no targets and fizzling the whole trigger. Can’t possibly be as intended since if you’re playing a discard build your opponent will frequently have 0 cards in hand. Another high rarity card which is very disappointingly broken.
It does work when opponent has exactly 1 or exactly 2 cards in hand, which is nice, but it should be triggering on 0.