After drafting, each player chooses a class card from Adventures in the Forgotten Realms. The class card exists in the command zone, with similar rules to that of a commander. Additional 2 mana for each time it has been cast. It does not restrict the contents of your deck.
Design Principles
Choose Your Class aims to deliver a fun, varied, competitive, and interactive game play and draft experience.
Most of the class cards should be viable.
The cube emphasizes themes that synergize with the class cards, especially themes that synergize with multiple classes.
I try to include cards with strong D&D flavor as long as they are playable and don't detract from the above goals.
Archetypes
There are sources of +1/+1 counters in every color, with the highest concentration in Green and White. There are a few sources of proliferate and other synergies such as Hardened Scales and Conclave Mentor.
Bard Class is supported by lots of legendary creatures and planeswalkers. Note that all planeswalkers are legendary even if it's not stated on the card. Bards can also benefit from the +1/+1 counters theme.
Cleric Class is supported primarily by the lifegain theme and has strong synergy with the +1/+1 counters theme. Clerics can benefit from the graveyard theme with their third-level ability.
Druid Class has a built-in synergy with the lifegain theme. Druids can ramp with land draw, Courser of Kruphix, and Radha, Heart of Keld. They are best equipped to take advantage of several strong landfall effects, including Field of the Dead. Bounce lands (Simic Growth Chamber) and lairs (Treva's Ruins) are most effective in the hands of Druids. There is no targeted land removal, so bounce lands won't backfire.
Fighter Class is supported by several pieces of strong equipment.
Ranger Class is just great. Rangers can benefit from the +1/+1 counters theme.
Sorcerer Class dovetails with the spells theme, and they have built-in discard, which can support reanimation.
Warlock Class has built-in synergies with the sacrifice and graveyard themes.
Wizard Class has built-in card draw, useful in any blue deck. The third ability may benefit from the +1/+1 counters theme.
Barbarian Class and Rogue Class are not supported. You can still choose them if you want, but I'm only trying to balance the power level of the other ten classes, and I don't expect Rogue or Barbarian to be competitively viable (especially Barbarian).