The truth is that certain things, although simple and intuitive in the real world, end up not translating so well into Magic-ese, and drawing cards turns out to be one of these things. Since the game can’t handle multiple card draws simultaneously, it ends up processing this action as separate individual card draws — so Blast of Genius actually turns out to read “draw a card, draw a card, draw a card, then discard a card…”
Where this ends up mattering in the real world is when you have a card that makes you reveal the top card of your library, like Melek, Izzet Paragon. Because the draws are treated as separate events, if you cast Blast of Genius with Melek on the battlefield, you’ll have to reveal each of the three cards you drew before discarding, because for a tiny moment between the draws, each card is the top card of your library (which must be revealed due to Melek). But assuming you were going to discard one of those cards, your opponent would get to see it anyway… right before it blasts him in the face!
Today’s Rules Tip written by Jen Wong