As Cubing becomes increasingly popular, more players are looking for an accessible entry point to the hobby. “Set Cubes”—Cubes constructed using only cards from a given set or block—are an appealing option to newcomers and a less daunting alternative to building a traditional Cube from scratch.

Unfortunately, anyone looking for advice about set cubes is barraged by conflicting information.

Graham Stark, of LoadingReadyRun and Strip Search fame, announced his plans for a Modern Masters set Cube, and the peanut gallery started chiming in with suggestions.

A 3/2/1 common/uncommon/rare ratio.



What's the right answer?

I've never been a proponent to adhering to strict design rules, but do recommend that designers learn the rules before they break them. All of the above ratios will produce a different gameplay experience, and all of them deviate from the ratios present in a retail set like Modern Masters. If we don't know what the standard is, we can't know how our choices deviate from the norm, and how those deviations affect the drafting environment.

The Retail Ratio

In modern Magic design, the cookie-cutter large set release contains 249 unique cards: 101 commons, 60 uncommons, 53 rares, 15 mythics, and 20 basic lands. In terms of pack distribution, mythics occupy the same slot as rares, and each mythic occurs at about half the rarity of a rare.

This means that over the course of 60 packs (ignoring foils), we would expect to open about 53 rares and 7 mythics.

For the sake of simplicity, we can think of a set as having 100 unique commons, 60 uncommons, and 60 "rares."

Further, an 8-player draft will have 240 common cards, 72 uncommon cards, and 24 rare cards (24 boosters with 10 commons, 3 uncommons, and 1 rare each, again ignoring foils).

Put it all together and we have the following:

A 6/3/1 ratio.

Next, there are two main questions that will dictate how you proceed:

• Do you want to stick to the retail rarity ratios?
• How do you want to create your Cube packs? Do you want to shuffle all the cards together in one big pile, or create packs with fixed rarity distributions (i.e. packs with 10 commons, 3 unncommons, 1 rare or mythic)?

Method 1: Retail Replication (Packing Packs)

This method is for players who want to perfectly recreate the experience of a retail draft, without the hassle of having to buy packs every time you want to draft. The approach is simple. Before the draft, separate your cards into three piles: commons, uncommons, and rares/mythics. Then create each pack by taking ten commons, three uncommons, and one rare/mythic card. Draft as usual.

The first advantage to this method is that you guarantee an even rarity distribution within your packs. The second, and more hidden advantage is that you need fewer cards. Since you are collating packs, you can achieve that perfect 6/3/1 ratio with as little as the following:

300 commons (3 of each)
120 uncommons (2 of each)
53 rares and 15 mythics (1 of each)

The biggest difference between this method and retail drafts is that you limit the variability of your draft pools if you only have 3 copies of each common. The expected number of copies of each common in a retail draft is 2.4 copies, but individual cards will often appear 4 or more times in an 8-man pod.

The approximate probability distribution of number of copies of a common card in a retail draft is as follows:

In total there's about a 22% chance that you'll see a given common 4 or more times in a triple-large-set retail draft. Naturally, the more complete sets of commons you have (say, 5 or 6 sets), the closer your drafts will reflect the variability of a retail draft, but the gains are relatively marginal. If you're looking to scrape by with the minimum number, three of each common will certainly suffice.

As for disadvantages, sorting the cards into rarity piles can be a little tedious. More importantly, it's hard to play with the rarity ratios within this “packing packs by rarity” method. I've seen players use an 11th common or a 4th uncommon in the pack, but it gets trickier if you want, say, 20% more rares in your environment.

Method 2: One Big Pile

Speaking of including more rares...

The “one big pile” method consists of gathering a selection of cards and shuffling them together for a traditional style Cube draft. Of course, this method has no guarantee on each pack containing a rare or mythic, but it also allows the designer to play with numbers much more easily.

Assuming that you are using 360-card draft pools, here are the average number of cards you will see in a draft using an approximate retail ratio (6/3/1/1) and two ratios proposed in the Graham Stark tweet at the top of the article.

The most important thing to realize is that by tweaking these numbers, we can dramatically alter the feel of the environment, and not always for the better. For example, below are Return to Ravnica's converted mana cost curves by rarity:

At a glance, we see that the common and uncommon curves roughly approximate what we would expect to see as a deck's curve. The rares and mythics are much more top-heavy. As we mix in more rares, we create an increasingly “bomby” environment.

The overall curve of the environment's cards won't change all that much, but it's important to keep in mind the distinction between rares and commons. Bombs are most frequently printed at the higher rarities, whereas the bulk of a set's removal will (thankfully) be at common or uncommon. As we shift the ratios toward more rares and fewer commons, the equilibrium between bombs and removal shifts as well.

The result is a move towards what is known in the Cubing community as “Dragon Magic:” games that are defined more by raw card power finishers than by interactive game play. With more costly bombs floating around, there are more cards that help slower decks stabilize, potentially making life more difficult for aggressive decks.

The downside to this method is that in order to get anywhere close to a reasonable ratio between commons and rares, you'll need a lot of commons and all accompanying sleeves. A 6/3/1/1 distributed pile requires a full 600 commons and 180 uncommons.

Method 3: The Hybrid

Lastly, there's a hybrid method that combines the design flexibility of the “one big pile” method with the low card count requirements of the “packing packs” method. Let's say I wanted my 360-card drafts to contain 240 commons, 90 uncommons, and 30 rares/mythics. With the hybrid method, we could do the following:

Before the draft, separate our cards into three piles: commons, uncommons, and rares/mythics. Then, grab the appropriate number of cards from each pile, and shuffle together the resulting 360 cards to draft.

Note that the packs won't have perfectly balanced rarity distribution. The major benefit here is that we can easily tweak the numbers from draft to draft. Decide 30 rares is too few? Grab a couple more the next time around.

This method is also quite well-suited to getting a proper rarity distribution in full-block Cubes. For a full Return to Ravnica block draft, one could use 1-2 of each common, and a single copy of every uncommon, rare, and mythic.

As a practical tip, I recommend having your players rarity sort their decks into piles at the end of each draft to minimize prep work for the next draft.

Tweaking a Pile

Retail sets must serve a wide variety of masters. They must provide the cards to keep Standard metagames churning. They have to be sufficiently accessible for New World Order. They must entice Commander players, and have a positive impact on the financial bottom line.

Each of these is tangential at best to the process of creating a great Limited environment. Game-ruining bombs meant for Constructed play are tucked away at higher rarities, but still enter the fold. Unplayable chaff pads the packs alongside cards that won't see play outside of an EDH table.

Even the best of sets could provide better gameplay if the draft environment were the sole concern. As a set Cube designer, you can disregard all the constraints that guide Wizards' designs. Wish there were more removal? Consider the Izzet guild underpowered? Think [card]Pack Rat[/card] was a massive mistake? Make some changes!

A set Cube provides the perfect opportunity to test your design chops in a controlled setting. The set has already been made, all you need to do is provide small tweaks to an existing design.

Personal Recommendations

When designing a set Cube, consider following modifications:

1) Trim the edges

Cards like [card]Umezawa's Jitte[/card] don't really have a place at a low-level draft table, and are typically greater sources of frustration than fun. Although one of the appeals of drafting is seeing what rares you'll crack each draft, some cards push things a bit too far. I'd take a hard look at the Jittes and [card]Pack Rat[/card]s of the set.

On the other end of the spectrum, cards like [card]Darksteel Forge[/card] will never escape the sideboard of an M14 deck. Worse, you don't even get the joy of rare-drafting in a set Cube.

2) Consider adding fixing

Retail sets are often a little light on fixing for my taste. A little bit of fixing goes a long way, with fewer games ending in color screw, and more room to experiment as a drafter. I certainly wouldn't complain if I saw a sprinking of shocklands in somebody's Modern Masters cube.

3) Adjusting aggro

If you're upping the density of rares, make sure your lower converted mana cost decks remain competitive. The obvious route is to increase the density of powerful aggressive cards. Another option is to look at the assortment of removal spells you are using. A [card]Pacifism[/card] is equally effective against aggressive cards and bomby finishers, whereas a more expensive removal spell like [card]Trostani's Judgment[/card] is great against Sphinxes and Dragons while still giving room for the Goblins and Soldiers of your set to breathe.

4) Vanilla replacement

Lastly, when looking to add spice to a set Cube, consider replacing some of the more boring vanilla cards with functionally similar upgrades. In a Return to Ravnica block Cube we could consider shaving a couple [card]Gutter Skulk[/card]s for [card]Blood Scrivener[/card]s. I wouldn't go overboard, but it's a nice option for adding texture and excitement to an environment without disrupting your mana curves.

Closing Thoughts

Building a set Cube is a great unintimidating way to dip your toe in the Cubing waters. It's also the perfect environment for tweaking variables and seeing how they affect drafting dynamics. If you have any questions, feel free to ask them in the comments below. Thanks for reading!

Jason's Cube Design Site -