The Two-Player Showdown cube is a pool of cards for 1 vs. 1 games of grid draft. It's designed to be easy to pick up and play.
This cube is designed around abilities and effects that are easy to use and give players opportunities to make decisions. Cycling, hybrid mana, convoke, and devotion are the most common mechanics:
To give players some direction as they decide which cards to draft, each color focuses on a theme:
ARTIFACTS Get creative with artifacts to build a legion of artifact creatures.
BLINK Play "enters" abilities for an immediate advantage, then re-trigger those abilities to stay ahead.
GRAVEYARD Use your graveyard as a resource and raise creatures back from the dead.
MODIFIED Suit your creatures up for combat with +1/+1 counters, equipment, and auras.
GO WIDE Flood the battlefield with creature tokens to launch a massive attack.
Stick to one color's theme for a monocolor deck or combine the themes in a multicolor deck. A deck for example can use "enters" abilities to make modified creatures and excels at slipping past blockers:
First off, shuffle the cube and flip a coin to decide who gets first pick. Each round of draft goes like so:
Repeat the process until 18 grids have been dealt. Each player then builds a deck with 40 cards minimum by adding any basic lands.
The easiest way to get a feel for the rules is to head to the playtest link above and simulate a grid draft.