By The Duel Commander rules committee

Before we delve into a minor rule change and individual card explanations we need to discuss the overall idea around this wave of unbans. Even with preliminary 20 life testing, blue and green continue to have powerful decks in the format, as we expected. Part of the initial change to 20 life was to promote players using white/black/red as base colors for decks instead of blue or green. With 20 life, red gained a visible advantage but black and white could benefit some help from unbans. Additionally, no blue or green cards were made legal in this update, so that we can see how the format grows from here. It is possible and likely that some blue/green cards might be unbanned at some point but we want to be especially careful not to shift back into a total blue/green dominance.

👉 First, regarding individual card changes:

Yawgmoth’s Bargain is now legal.
Serra Ascendant is now legal.
Grindstone is now legal.
Necropotence is now legal.
Balance is now legal.

👉 Second change, now, about the players’ starting life totals. As a reminder of our last announcement, Duel Commander is now to be played with 20 starting life totals for players. This is a change from previous rules. This change is now effective, and playing with 30 starting life totals are not supported anymore, as opposed to what was the case during the last two months of transition.
👉 The third change for this announcement is the removal of the 21 commander-damage rule removal. Starting this day, this rule does not exist in Duel Commander anymore. Official documents have been updated accordingly.
Playing with 20 starting life totals raised questions about the relevance and the maintenance of the 21 commander-damage rule. The new “partner” ability from Commander 2016 made this concern more important, recently. Indeed, this new ability comes with a few practical concerns, for it would now be necessary to individually note each and all of the separate commanders cumulated damages, as well as increasing or decreasing life totals, which could make up to six points totals to note.
We deeply regret the removal of this rule, which contributed to the spirit of the game and of the Commander format (and therefore, formerly, Duel Commander from its birth to this day). Please also note this update enhances life-gain strategies, which is a secondary, yet positive consequence, especially in a metagame where extremely aggressive decks could arise.
Balancing the format as well as making it more playable prevails on a certain nostalgy. Therefore, the 21 commander-damage rule is now removed from Duel Commander.

These changes apply on November 11, 2016. The next announcements will be published on January 16, 2017 (applying on January 20, 2017).

Until then, we wish you all many good games! 🙂

Further individual explanations:

Yawgmoth’s Bargain
If Yawgmoth’s Bargain remains without a doubt an awesome card advantage engine, it is true that in can also evolve into an amazing combo engine, when contextual format construction rules allow to do so. Such an abuse of Yawgmoth’s Bargain is unlikely in Duel Commander. The singleton construction rule, along with the high number of cards in the players’ libraries are close to being almost insurmountable constraints when it comes to building a system-based deck (like storm or eggs), for they drastically diminish the means of redundancy. On the other side, limiting mana acceleration resources and life totals at the start of games contributed in reasonably calibrating the power of this enchantment.
In fine, Duel Commander helps finding again the initial purpose of Yawgmoth’s Bargain: a card advantage engine, both resisting and prolific for decks that aim at controlling games. Such a use is absolutely acceptable in the current Duel Commander environment and Yawgmoth’s Bargain is therefore legal again.

Serra Ascendant
The adjustment on the number of life points at the start of the game made the restriction on Serra Ascendant perfectly obsolete. This card is now legal again in Duel Commander.

When Grindstone was banned, the combo (along with Painter’s Servant) could be set up very quickly (for cards like Ancient Tomb or Grim Monolith were still legal) and removal spells were little played (as aggro was weak with 30 life totals). Now, this combo is less toxic, slower and easily disrupted by any color (unlike the ones that use Necrotic Ooze). Those constraints therefore require creating a new archetype for Duel Commander, a classic combo deck, coming from eternal formats, open to all colors, offering a high number of building possibilities.
The new dynamics of Duel Commander induce that combo decks do not prevail anymore. We choose to include Grindstone back in the format.

Reducing the starting life totals widely “framed” the potential of Necropotence. It was obvious that 30 starting life points as a basic game mechanic fully justified its sidelining so far. Moreover, the specific construction rules of Duel Commander (singleton decks along with the number of cards in libraries) are very hostile to such a structuring card that Necropotence is. It is then a golden opportunity for Duel Commander to reconnect with an emblematic eternal-formats card, that is able to reinforce the interest of people in a misrepresented colour. The famous black enchantment is now back on the Duel Commander tables.

Balance is a degenerate card when played proactively (i.e. emptying one’s hand then playing Balance very early, with no creature on the battlefield and almost no cards in hand). Balance is also a reactive card, kind of a “panic button” when the situation is turning bad, but wiping out the battlefield with Balance is often at the cost of your hand. In Duel Commander, proactively setting up Balance can rarely be done (a few moxes, few low cost tutor effects, only one copy of Balance) and therefore, the card will mostly be played as a reactive – and reasonable – answer.
Following our will to make the format more spectacular, as opposed to the morose dynamics of formats like Modern or Standard, we chose to make Balance legal again in Duel Commander.