How to build and draft a Riftbound cube

Instead of opening sealed product, you build one pool of cards yourself, usually a few hundred, and draft out of it. A cube can be a list of the most powerful cards printed, a budget pool, a single-set pool, or a themed one built around a region or a mechanic. The possibilities are endless and this is a big part of why Cubes live in my head rent free!

Cubes can be singleton (one of each card) or you can have more than one copy of cards in the cube (looking at you, spiderling enjoyers). Running three copies of a card you want turning up often is a normal thing to do, and it is how you control how frequently an effect shows up in packs.

Riftbound decks are not one pile of cards. A deck is a legend, a main deck, a separate rune deck, and a set of battlefields. That has three consequences for drafting.

Legends determine domain identity. Your legend determines which two (or sometimes three in limited) domains you can access, and you play exactly one. A legend in a normal pack is a card most seats cannot use, and a drafter who never sees one has no deck at all. That is why many cubes guarantee legends rather than leaving them to the shuffle.

Battlefields are a small, separate slot. You need a handful and no more, so they have a similar problem. Valuable to everyone, but only up to a point.

Runes are resources, not picks. Almost every cube supplies them from outside the draft, the way a Magic cube supplies basic lands — drafting them would mean spending picks on your own mana base. A cube with no runes in it at all is perfectly normal.

Signature spells are another interesting wrinkle. Most cubes I have seen allow any deck to play signature spells regardless of legend. This creates some very interesting legend and signature spell combinations that are not possible in constructed! Feel free to experiment with your own cube here.

When deciding how many cards to put in the cube, you need to consider a few things. How many players will be drafting the cube? How many packs will you open? How many cards will be in each pack? At a baseline, you need enough cards to fill the packs. Beyond that, it can be interesting to think about whether every card shows up every draft (if there are exactly enough cards to fill the packs), or if there will be some cards that are not in the packs on any given draft (more cards than are required). There are so many permutations and ways to play a cube. The best way to learn what your group prefers is just to try something and see how it goes! Iteration is the name of the game with a cube.

Legends and battlefields need their own count. If every pack guarantees one legend, an eight-seat three-pack draft wants 24 legends. The Cubebound card browser filters the full pool by set, domain, energy cost, type, rarity and trait, which is the fastest way to see what is actually available in a domain before you commit to it.

There are two approaches, and they suit different cubes.

1. Reserved slots. Each pack contains a fixed number of legends and battlefields, and the rest comes from the main pool. From Legacy (Set 6) onward, Riftbound’s own boosters guarantee one legend or battlefield per pack, chosen at random, and that is the model most cubes copy. Reserved slots come out of the pack size rather than on top of it, so a twelve-card pack with one reserved slot is eleven main cards. This guarantees every seat gets shots at the cards their deck cannot do without.
2. Shuffle everything together. Legends and battlefields go into the main pile and turn up wherever the shuffle puts them. Simpler, and some groups prefer the swinginess, but you should expect seats to occasionally end up with no legend, so agree in advance what happens when they do.

A common third variant is a legend phase: before the main draft, everyone drafts a small pack of legends only (two per drafter is typical) so every seat starts with an identity and drafts toward it. It costs one extra pack and removes the worst outcome in the format.

One of the most exciting things about Riftbound cubes is that drafting conventions are still community-defined. The game is young enough that no single approach has settled. The questions worth answering before you and your friends start a session:

• Deck size. A fixed number keeps games comparable, and plenty of cubes settle on one rather than using the constructed minimum. Whatever you pick, the size you choose interacts with how many cards each drafter ends up with, so it is worth revisiting after your first session.
• Legends. Drafted, or picked freely after the draft the way runes are? Some groups treat the whole legend pool as available to everyone, which removes legend screw entirely and makes the draft purely about the main deck.
• Battlefields. Drafted, or a shared pool everyone builds from?
• Domains. Up to three is the standard limited rule. Depending on how the cube is designed though, two domains only can be totally doable.

Whatever you land on, write it down where drafters will see it. Every cube on this site has a primer, a long-form write-up attached to the cube, and it is the right home for exactly this.

The quickest way in is to look at what other people have built. Explore lists public cubes, and any of them can be cloned into your own account under a name you choose and changed from there.

When you are ready to test it, you can draft any cube on the site against bots without waiting for a group, choosing seats, packs, pack size and how legends and battlefields are dealt. The bots are very stupid for now, but it is so satisfying to see your cube at work!

When you have a group, any cube exports to Draftmancer, which runs the draft for the whole table in the browser. Here’s how to draft with friends on Draftmancer.

Good luck out on the Rift and happy cube-ing!