Written by Pipsqueak
I think the line between custom set design and canon Cube design is growing thinner and thinner with every passing year. And as a result, I think the custom community has a lot that it could stand to learn from the Cube community.
Cube, as a Magic format, has always had a large degree of self expression. Even if you were trying to build the most 'classic' version of Vintage Powered Cube imaginable, your vision for what that meant was going to be influenced by when you started playing Magic, when you started playing cube, and what decks you most strongly associate with the Vintage Cube experience. And while that was already somewhat true a decade ago, it has become much more true with time.
There's been several things pushing the cube community in the direction of self expression, but fundamentally it is because Cube is one of the best (canon) Magic experiences when it comes to curating your own experience. If you hate new cards, or want a specific flavor vibe, or a specific play experience, and you don't do custom Magic, Cube is one of the few avenues available to you where you have total control over the end product. Cube is less like building a deck, and more like building an original set using entirely (or largely) an existing set of tools.
I want to talk about three types of Cube projects here (which share a degree of overlap), each of which has lessons to teach custom designers: Vibes Cubes, Context Shift Cubes, and Rules Modification Cubes.
"Vibes" Cubes are a broad category (that I'm naming) that encompasses plane cubes, set cubes, and aesthetic cubes. To a lesser extent, format cubes (like old school or pre-modern cubes) can be thought of as part of this category as well. What all of these cubes have in common is that they have a specific vibe that they're trying to convey to anyone who is drafting them or looking at them. That vibe might be "What it was like to draft triple Innistrad", or "What does the plane of Ravnica have to offer", or even "What would a film noir Magic set look like?" The starting seed might be a purely flavorful one, a purely mechanical one, or somewhere in the middle. But what's great is that once the Cube creator understands that seed, it becomes something of a mission statement, a touchstone they can always come back to.
When making a Custom set, we constantly have to ask ourselves what we're trying to convey to players, and how to convey that successfully. Often people point to art or flavor as the most important parts of this process, which sometimes solicits groans from designers. After all, we do not have an infinite art budget or total control over all the artistic details of our sets. But I think one thing that projects like the Pulp Nouveau Cube highlights is that people are capable of cultivating these types of vibes with zero modification of art or flavor, just using existing cards. If they can do it, so can we.
Furthermore, it's important in cubes like this not just to pay attention to the aesthetics of the experience, but also the play patterns. People who manage old border style cubes do often add cards printed in old border treatments post 2021 (starting with Time Spiral Remastered). Typically, however, they are only adding specific cards, ones that fit the older gameplay patterns that they're trying to convey. Read the Bones, Talismans, sure. Ugin? Nah, no shot.
I think this part is a really fine line to walk as a custom designer. While it is possible to overdo it, and get so hung up on flavor that you ignore what plays well, I think it's also very easy to create an environment that looks and reads like it should convey one vibe, but ends up conveying another vibe in terms of actual gameplay. If you're trying to sell me the idea of violent skirmishes in the streets, and the actual gameplay is grindy boardstalls won via people going over the top, that's probably going to end up missing.
The last takeaway I want to highlight of Vibes Cubes is that bit about "mission statements". Some magic sets struggle to have a concise elevator pitch, which in turn leads to them struggling to form or keep a single cohesive identity. Either via constantly shifting, or via trying to encompass too much. I think that often it can be really helpful to try and establish, as soon as possible, the core premise of your custom project. Once you have it, you can constantly turn to it as a form of "true north" when you're unsure which direction to take.
Next up, we have Context Shift Cubes, which are cubes that (broadly speaking) have some structural element that means that drafting the cube is an exercise in understanding how this structure differs from normal magic, and changing your picks and deckbuilding accordingly. They achieve this without any change to the rules of how the game is played, just by changing what cards are available. Desert Cubes are a classic example of this, where the cubes do not contain basic lands other than ones opened during the draft, thus requiring you to pick lands highly if you want to cast your spells. Perhaps the most famous (recent) example of this is Andy Mangold's 100 Ornithopters Cube, where the only wincons available to you are 100 copies of the card Ornithopter, and various ways to buff them or convert them into other resources.
When making custom sets, it is important to remember that we have at least as much control over our limited as Cube creators, if not more. If you want a gameplay defined by low resources, you can just avoid putting cards into your set that fight against that goal. If you want people to pick a faction and hard commit to it, you can alter what fixing is available to try and encourage that behavior. And even beyond limited, the tools that you intentionally choose to provide players, or choose *not* to provide players, has a huge impact on the constructed format that your set ends up in. No set should try and provide everything a player might need; instead, just make sure they have some of (and not necessarily all of) the tools they need to highlight your set's themes.
The last group I want to touch on are Rules Modification Cubes. This encompasses any Cube where there is some modification to the core rules of Magic, ranging from something as simple as a Commander Cube to things substantially wilder. Anthony Mattox's Turbo Cube has both players start with an emblem discounting all of their spells and activated abilities by 2 generic mana. Prophetic Prism is now a cantriping Mox. Stuffed Bear is a 4/4 for 0. Games are often decided on turn 1. Or the Reading Rainbow Cube, where both players start with a Pillar of Paruns in play. Or the Cascade Cube, where the first spell each player casts each turn has cascade.
These Cubes are wild, and a ton of fun to hear about, talk about, and try out. They're still entirely made up of "canon" cards, but via changing the rules of the game, the result is something that plays remarkably differently from canon Magic. Sometimes, even more so than the average custom set, which I think often endeavors to feel like "Wizards of the Coast could print this." These Cubes invite us to think outside the box, to question our underlying assumptions for how games should play. I think if more custom designers were aware that this was an option, that you could design cards normally but alter the rules so they play differently, we might see some kinda wild projects arise from it.
All three of these types of Cubes also raise another lesson that I think people should internalize: gameplay does not always need to be "good" to be interesting, or fun. I think the custom community is very good at trying to encourage people to a baseline level of good gameplay, staying away from hardcore mana denial or turn 1 wins or overly punishing boardstates/decision making. And I think for anyone who is likely to stumble into those things accidentally, that's great. But people having the ability to intentionally deviate, and see what the resulting experience is like, is important too.
The concept of a desert Cube is something that I can't imagine making it far in most custom circles; people would be too concerned about the average player screwing over their draft and being unable to cast their spells. And yet there's hundreds, probably thousands, of people out there who have drafted and love desert Cubes. This ties back to my previous point, that often the custom magic community is drawing inspiration from WotC, whose primary goal is to sell product and maximize the appeal of their sets. And for many sets, that's great! But not all sets need to be like that all the time. The ever growing Cube community shows otherwise.
I'm confident that the lessons I've listed here are just scratching the surface of potential things that the custom community could learn from Cube. This isn't intended to be exhaustive, but instead a jumping off point. The more time and effort we devote to understanding how the other half lives, the more likely we are to come away inspired for our own projects.