A couple weeks ago, I kicked off a series of articles on when you should put a certain number of a card in your deck. You can check out the first one in the series, "Four of a Kind," here.

In that article, I covered perhaps the most common number in a traditional Magic deck: four! Playing four copies of a card gives you the highest chance of drawing one of them, and there are lots of reasons as to why you might want to do that.

But what about three?

If I'd classify four-ofs as cards you basically always want, I'd say three-ofs are cards you conditionally want. They're certainly cards you're happy to have in your deck—but they might not be exactly something you want to draw loads and loads of.

So, why would you play three copies of something? Let me cover five of the most common reasons.

1. You don't want to draw this card in multiples

Playing four of a card means that you have to accept some games you're just going to draw multiples of them early. Playing three is a way to help curb that problem.

Why would this be the case? Well, for example, what if your card is legendary?

Drawing one is great for your deck—but drawing a second will often be a dead card. Drawing three is a huge problem!

In the case of these Goggles, it's especially damaging because they are a noncreature permanent. That means your opponent has to have a pretty narrow card to deal with it before you can play your second. With a creature like Zurgo Bellstriker, there is at least the thought that your opponent might kill it or it might die in combat so you can play your second.

There are exceptions—Mox Opal comes to mind—but in general, you want to be careful around playing the full four copies of legendary cards, especially if they're noncreatures. This is also true about planeswalkers to some degree, though not quite as much because those die to damage like creatures.

There are also some cards that are redundant in multiples.

The first one is great for your deck, but the second one is a dead card. It's the same problem as legendary.

If there's any card you don't want to draw two of early, then three copies would be a good number to consider.

2. This card is expensive to cast for your deck

One of the most common reasons I play three copies of a card—and piggybacking into a vein similar to my first point—is because it's at the upper price of what my deck expects to cast.

You can basically always find time to cast a one-mana card. But a five-mana card? That's a bigger resource drain.

Imagine you draw two Archangel Avacyns early on. You can't even begin to do anything with them until you have five mana. And then, once you do, it means you can't do much else that turn. While it's a nice curve-topper, it's not something you want to risk being clogged on.

It's important to note that this is all relative to your deck. A five-drop might be incredibly easy to cast in your green ramp deck, and a four-drop might be the absolute top of your curve in your 20-land mono-red deck. One way to think about it for some decks is this: When you play the last land in your hand, what card do you expect to want to slam down?

Drawing two copies of a three-of certainly does happen sometime, but playing one less than the maximum just helps mitigate that risk.

3. The card requires setup

Some cards are totally great when they synergize with something else—and total whiffs if they have nothing around to work with.

A common example of something like this is an Aura or combat trick you want to put on your own creature.

To make a creature Aura good, first you need a creature that you want to enchant it with—and preferably one that can attack this turn to reduce the potential of getting two-for-one'd.

While a card like Unflinching Courage may be strong, getting stranded with two in your hand while you're desperately looking for a creature is not quite what you want.

But it's not just things that enhance your creatures. You could also look at a card like Sleep.

Imagine you wanted to play something like Sleep as your finisher in an aggressive blue deck. Well, for it to be good, first you need to have a board of creatures. It requires a bit of setup to get there before Sleep is going to be at its maximum potential—and after you cast it, the game is likely over, meaning you don't really need any redundant ones. (Sleep could also be a fine one- or two-of, but that's a story for another week.)

4. This card is best against certain kinds of decks

There are some cards you may want to main deck that are extremely good against certain decks, but just okay against others. For example, take Anger of the Gods.

This kind of sweeper is excellent against small creature rush decks. However, it's poor against control decks and just okay against midrange decks packing some small creatures and some big creatures.

Playing three copies gives you a chance to find one Anger early when you need it (especially if you have any kind of card-filtering effects), but helps hedge you away from having a hand full of useless Angers.

Note that this is different from cards that are only good against a specific deck or kind of deck (like a Shatter, which is going to be completely dead against decks without artifacts). These are cards that might just be okay in some matchups, but shine somewhere else.

5. You're creating a split

In deck building, there's something I like to call a "split." It's a technique used to enhance diversity in your deck among similar cards. It's a pretty simple concept: instead of playing the number of copies of something you were going to play, instead you split them.

For example, a split would be to play 3 Doom Blades and 1 Hero's Downfall in your black deck.

In many situations they're going to be similar—but Hero's Downfall just makes you slightly better against planeswalkers and removes one useless removal spell from your deck against planeswalker control decks. It also gives you one less card that's weak against other black decks.

Three-one and three-two splits are fairly common. When you see a three-of somewhere, check it against other cards in the deck—it may just be there to create redundancy.

Third Card's the Charm

That about wraps up some of the most common reasons you'll end up with three copies of a card in your deck. As always, there are exceptions; I'm sure you can look over famous decklists and find points of difference. But as a place to start? These make for excellent guidelines.

And, as always, nothing will tell you as much as playing games! Use this as a starting point, then play games and use that data to modify how many of a card you're playing. Playing your deck is the most useful way to find out information about how your deck plays!

Curious about this article or have any thoughts? Maybe you came up with a question you want to fire off my way? Send it over! You can always reach me on Twitter and Tumblr, or by sending me an e-mail at BeyondBasicsMagic@Gmail.com.

Talk with you again next week!