Cube is the format where you build the format. You curate 360+ cards, your friends draft from them, and the games you produce reflect the choices you made. It's the most rewarding deckbuilding exercise in Magic, and the easiest to do badly.
The size question
The default is 360 cards because that's what eight people drafting three packs of fifteen each consume. You can build smaller (180 for a four-player cube) or larger (450+ for redundancy and variance), but 360 is the standard for a reason: it produces drafts where every card sees a pick decision and nothing is wasted.
The power-level question
Before you pick a single card, decide: what power level are you building?
- Vintage Cube. Power 9, fast mana, broken cards. Defining games are won on turns 1–3.
- Powered Cube. No restricted cards but lots of premium staples. Defining games on turns 3–5.
- Unpowered Cube. Constructed staples without fast mana. Defining games on turns 4–7.
- Pauper Cube. Commons only. Defining games on turns 5–9.
- Set Cube. Cards from a single set or block, closer to Limited.
This decision drives everything else. Mixing power levels is the most common new-cuber mistake.
The five-color split
Most 360-card cubes allocate roughly:
| Color | Slots |
|---|---|
| White | 50–55 |
| Blue | 50–55 |
| Black | 50–55 |
| Red | 50–55 |
| Green | 50–55 |
| Multicolor | 30–40 |
| Colorless artifacts | 20–25 |
| Lands | 25–35 |
Adjust if you want a color to be stronger or weaker. Resist the temptation to make one color noticeably bigger than the others, drafters notice within two pods.
The archetype question
Pick 6–8 archetypes you want to support. Common ones:
- White-Black aggro
- Blue-Red tempo / spells
- Black-Green graveyard / sacrifice
- Red-Green midrange / ramp
- White-Blue control
- Blue-Black control or reanimator
- Black-Red aggro
- Red-White equipment
- Green-Blue ramp / blink
- Green-White tokens / +1/+1 counters
Each archetype needs:
- 5–10 cards that only it wants, the payoff cards.
- Shared support cards, efficient creatures, removal, fixing.
- Exit ramps, cards that work in adjacent archetypes if the draft pulls you elsewhere.
A cube is a set of paths through itself. Each draft picks one path; the cube has to support all of them.
How to ship version 1
Don't perfect it. Build a draft-ready first version, run it with friends three or four times, take notes on what didn't work, then iterate. Cubes get better through play. The cubes that never ship are the ones whose owners spent six months tuning a list nobody played.