For the next few weeks, Reid is revisiting some of the key concepts of Magic, updated for Magic Origins. These concepts are so important to learning Magic that we wanted to reintroduce them to the next wave of Magic players. Enjoy.

The Cost of Playing a Spell

Last week, I named mana as one of the fundamental resources of Magic. When you want a particular effect on the game, you amass the proper mana and cast a spell that will cause your desired result. That much is fairly simple, but it's not the only thing that happens when you cast a spell. Consider these two cards:

If you need to block a creature with flying, you could cast a Hitchclaw Recluse or you could build a similar creature by using Mantle of Webs to enchant, say, a Bellows Lizard. In either case, you're spending three mana and winding up with a four-toughness creature with reach. With the Bellows Lizard, your creature even has an extra ability and lets you pump your Lizard up for two mana! Looking at things just from the perspective of mana, you would never choose the Hitchclaw Recluse.

However, the reality is that casting Hitchclaw Recluse is the far more efficient way to produce this effect. In fact, Bellows Lizard and Mantle of Webs are both rather weak Magic cards. It's true that, in terms of mana—one of Magic's fundamental resources—these two options cost the same amount. However, in terms of Magic's other fundamental resource, the two options are vastly different.

Casting Bellows Lizard and Mantle of Webs costs you two cards out of your hand, while casting Hitchclaw Recluse costs you only one card out of your hand.

You start the game with seven cards in your opening hand, and you get to draw one more each turn. This puts a strict limit on what you have to work with in a game of Magic. If I cast Bellows Lizard and Mantle of Webs and you cast Hitchclaw Recluse, we've both spent three mana, but you've gotten the better of me. We've both produced an effective defensive creature, but you'll be left with one more card in your hand, which might help you pull ahead in the game in any number of different ways.

Card Advantage

Players who do not treat cards as a resource are likely to be frivolous, squander their spells, and quickly run out of things to do in a game of Magic. They'll soon be at the mercy of the top of their libraries, which is a frightening and unreliable way to play. A player who does treat cards as a valuable resource, on the other hand, will squeeze every bit of value out of each spell, and do everything possible to pull ahead in a game.

Card advantage is, very likely, the single most important concept in competitive Magic. A tremendous proportion of games are decided, in one way or another, by card advantage.

The term is nearly as old as the game itself. One of the founding fathers of Magic writing and theory was Eric Taylor, who defined it like this: "Card advantage is any process by which a player obtains effectively more cards than his [or her] opponent."

If that definition seems a bit nebulous, it's because card advantage can take such a tremendous variety of forms. Let's start with a simple one.

Drawing Extra Cards

Here, card advantage is just a simple matter of counting. When you cast Weave Fate, you draw two cards. Don't forget, however, that it costs you a card to play a spell out of your hand. Weave Fate nets you one card. Jayemdae Tome draws you an extra card each time you activate it, but requires the initial investment of one card. If you activate it four times, it will net you three cards. Both of these spells provide fairly reliable card advantage.

Note that if a spell had no other effect except to draw you one card, then it would not provide card advantage. Imagine you cast Dark Dabbling not to save your creature, but just to see a fresh card off the top of your library. You would draw one card and spend one card, with no net gain in card advantage.

Read the Bones has a similar effect to Weave Fate, except that it costs you 2 life and you get to scry 2. Losing life and scrying are both important in a game of Magic, but it's very hard to make any direct comparison between these different effects. In counting card advantage, you would also say that Read the Bones nets you one card, and any other consequences of casting the spell would need to be considered separately.

Card advantage is about more than just the number of cards in your hand. Typically, adding a permanent to the board should be counted toward card advantage as well.

Remember that a spell which draws you one card offers no net change in card advantage; you simply break even. With Tower Geist, though, you get to add a card to your hand while also adding a creature to the battlefield. Like Weave Fate, this is a net gain of one card. You wind up with a 2/2 flyer in play, but the same number of cards in your hand!

Taking Away Your Opponent's Cards

By definition, the term advantage has to do with your own position relative to your opponent. You can gain card advantage through favorable interactions with your opponent's cards.

You cast Mind Rot and knock two cards out of your opponent's hand. As always, you're down the one card that it cost to cast the spell from your hand. However, your opponent is down two cards for your troubles. Although both of you are technically down on cards, card advantage is relative. Your opponent is down one card more than you are, so you've "gained" one card.

For the purposes of card advantage, attacking your opponent's permanents is the same as attacking his or her cards in hand. When you cast Languish, you have the potential to eliminate several of your opponent's creatures at once. If three of your opponent's creatures die, but only one of yours dies, then you've lost two cards (Languish and your creature) and your opponent has lost three. Again, you've achieved a net gain of one card.

Virtual Card Advantage

Counting card advantage in the way described above is simple, it's helpful, and it's good to get into the habit of doing so. Unfortunately, it often doesn't tell the full story of what's going on in a game.

In a very strict technical sense, Dragon Fodder adds two creatures to the battlefield, and should therefore be considered two-for-one card advantage. Sure, in the exact case where I attack you with two Bellows Lizards and you block with your two goblin tokens from Dragon Fodder, then it has traded for two of my cards, and it's fair to describe the spell as having provided card advantage.

However, a shortcoming of the simplistic method of counting card advantage is that Dragon Fodder and Priest of the Blood Rite are treated as the same card!

Both cards put two creatures onto the battlefield, and therefore provide two-for-one card advantage. But how can you account for the fact that I, as your opponent, need only play a 2/2 creature before those goblin tokens can no longer profitably attack? How can you account for the fact that my 5/5 flying demon might win the game all on its own?

In practice, games of Magic reach a point where some cards are capable of affecting the outcome and some cards are not. At points like this, it can become misleading to continue counting spells like Dragon Fodder (or anything else that's unlikely to change the outcome of the game) as card advantage. Instead, it can be more helpful to consider virtual card advantage, which (while being more difficult to quantify) accounts for the fact that not every Magic card is the same or, for that matter, equal.

Dead Cards and Blanking Cards

Anyone who's ever suffered from a mana flood can tell you that games sometimes reach a point where drawing more land is simply not helpful. Once you have enough mana to do everything you want to do, extra lands can become dead cards—they no longer impact the game at all.

One way to gain virtual card advantage is to blank one or more of your opponent's cards—turn them into dead cards. This might sound like an advanced concept, but I'd venture to guess that everyone reading this has done it before. If you've ever played a big creature to block, then you've blanked your opponent's attackers!

Once you put a Pharika's Disciple onto the battlefield, your opponent's 1/1 and 2/2 creatures can no longer profitably attack. That Pharika's Disciple can serve to blank essentially any number of small would-be attackers, providing the potential for virtual card advantage.

If your opponent has cards like Mind Rot or Nightsnare in his or her deck, you can employ a strategy where you cast all of your cards right away and never have anything sitting in your hand. If you do, you've blanked any future discard spells your opponent might draw off the top of his or her library.

Similarly, you can blank cards during deck building. If you're worried about facing the card Smash to Smithereens, you can simply build your deck with no artifacts. You've suddenly turned that Smash to Smithereens into a dead card!

Reducing the Risk of Dead Cards

On the other hand, you can also earn virtual card advantage by avoiding dead cards or finding a use for cards that might otherwise be dead.

Imagine a game that's dragging on and on. Maybe it's gone fifteen turns, maybe it's gone twenty. Neither player can get much benefit from any land beyond the sixth or seventh. However, while Johnny is sitting there getting frustrated with every useless land he's inevitably drawing, Jenny is using her Sigiled Starfish to scry-to-the-bottom all of her extra lands and low-impact cards, making her draw steps more effective and digging toward the cards that actually matter.

The Sigiled Starfish has never technically given Jenny card advantage, it's simply changed what cards wound up in her hand. Nevertheless, it's given her virtual card advantage by helping her avoid dead cards.

Low-Impact Cards and High-Impact Cards

Often it only takes a quick glance at a game of Magic to tell that some cards have simply been outclassed. Bellows Lizard is an example of a card that's very likely to be outclassed and very unlikely to change the outcome of a game. Bellows Lizard is a low-impact card. That's why, despite its affordable mana cost, it's often left on the sidelines.

Technically speaking, Dragon Fodder provides a two-for-one advantage. However, if one player casts Dragon Fodder and the other plays Shivan Dragon, who do you think came out on top? Shivan Dragon is an example of a high-impact card. It's the type of card that's very likely to swing the outcome of a game if it goes unanswered.

Putting an emphasis on high-impact cards is one more way to earn virtual card advantage.

It's not always the player who technically gains card advantage who wins the game. One player might be casting Weave Fates until the cows come home, but if he or she is only drawing into Bellows Lizards and Dragon Fodders, then it might only take one high-impact card like Shivan Dragon on the other side of the table to make it all look silly.

It's important to understand the theory behind card advantage and be able to count card advantage in simple exchanges. However, there are also times when the technical way of looking at things is not enough and you should recognize when virtual card advantage can be just as important.

Competitive Magic often runs on very thin margins, and small sources of card advantage like a two-for-one trade or blanking an opponent's card can easily be the difference between a loss and a win. Card advantage is at the heart of much of the game's strategy and theory. You'll encounter these concepts again and again as you read Level One. For now, though, I hope this has served as a helpful introduction—or refresher course—for a very deep concept.