If you dont, you may put a land card from your hand onto the battlefield. If you can plot a card, cast something from your graveyard, from exile, from someone elses hand or directly from your deck, you can put something of your choice into play from your hand
They are most likely backups or second picks for other, stronger cards, but if you need redundancy, these cards might be worth playing
Target player draws cards equal to the greatest mana value among permanents you control
6 Thing In The Ice - Awoken Horror Spellslinging decks are getting a huge upgrade with Thing in the Ice
For one, I'd think about my deck
Maybe the connection is a creature type, or the cards play well together, or they have some story element in common. And, unlike Draft Boosters, there is only one guaranteed uncommonwhile the other five cards all have a chance of being common or uncommon