This game works like the card game War i.e. you and the zombie you're fighting each put out a card. (You can click and drag/tap and drag on most devices, but on some touchscreens you'll need to double tap to choose your card instead of dragging.) The card with the highest specificity wins a point. There are a few twists, however.

1. You can pick from one of five cards to play. (It's not blind like with War)
2. After the cards have been played, you can guess whether the specificity is lower, higher or the same. You earn a point if you answer correctly.
3. If the specificity is equal, no one wins a point for the fight, but you can still get a point if you guess the specificities are equal.
4. To win, you need 26 more points than the zombie (not 52 cards ahead like in War).
5. A winner is only declared after every five fights. So even if the zombie gets ahead by 26 points, you have until the end of the five fights to turn things around.
6. If you win, you can claim a free set of CSS cheat sheets from the Undead Institute store ($2.99 value).
7. If you lose a zombie eats your brain.