These 3 cards are pretty normal in terms of rules, but I'm posting their faqs anyway, in case anyone wants to read them. Really the only question you can ask is, if I Crown an Investments and trash it for VP, can I get VP on the 2nd play? No, you can't.
Actually since this is the last chance I'll have before it's too late, I will make the bold prediction that tomorrow, people will complain about how their favorite card died, and how their least favorite card survived.
Magnate:
• For example, if your hand had two Coppers and a Silver, you'd draw 3 cards.
War Chest:
• The first War Chest you play in a turn can't gain whatever card they name; the second can't gain the card they name, or the card they previously named, and so on.
• The gained card comes from the Supply and is put into your discard pile.
• You can still gain the named cards other ways, just not via War Chests.
• They do not have to name a card in the Supply; however War Chest gains a card from the Supply, and puts it into your discard pile.
Crystal Ball:
• If you don't choose to do any of those things, you leave the card on your deck.
• If this plays an Action during your Buy phase that gives you +Actions, that doesn't let you play more Action cards in your Buy phase; if it draws Treasure cards, you can still play them.
Investment:
• You trash a card no matter what; it's okay if Investment was your last card in hand, you just fail to trash a card then.
• Then you choose either to get +$1 or to trash Investment.
• If you trash it, you reveal your hand and get +1VP per differently named Treasure there; for example if you reveal two Coppers and a Silver, you get +2VP.
• You can still play the revealed Treasures after resolving Investment.
Clerk:
• A player with no cards in their deck will have the card they put on top become the only card in their deck.
• At the start of your turn, you may play any number of Clerk cards from your hand, one at a time, without using up your regular Action play.