They never saw it coming. You have to know when to hold em, know when to fold em, know when to walk away, and know when to run. In an effort to keep the game fresh and exciting, Wizards of the Coast releases periodic expansion to the Magic universe. Some are excellent, some are only pretty good. It's one of the best ever released.
Invasion sports a lot of new features never seen before.
Some new cards now have a kicker, an optional casting cost that can boost the effect of a card later in the game, at the cost of a slightly less effective cost early in the game. In addition, the new set also introduces the split card, a card with two mini cards printed on each card. Each half is less effective then a comparable spell would be, but the added flexibility of having two choices of which card to take can more than make up for the deficiency. Dual lands also make their triumphant return to Magic the gathering. This time only in allied colors, and they have the drawback of coming into play tapped, but still an amazing boon to multicolored decks.