Format overview
Quick start Guide
Pick a legendary creature you like from a Modern-legal set. It becomes your commander.
Add 99 other cards that are either basic land cards (as many as you need) or cards from Modern with no other symbol than the ones you see on your commander card that you chose in step 1 (but only one of each, not more!).
Find a friend, or just someone who plays this too!
Start the game with your commander apart in the command zone, the rest of the game happens like any other Magic: The Gathering game!
Just know that you can play your commander from your command zone like you would play it from your hand!
If your commander goes to the graveyard, to exile, to your library or to your hand, you can put it back to the command zone, but each time you do this, you’ll need to pay {2} mana (two generic mana, i.e. from any source) more to cast it the next time you want to do so!
Enjoy!
BUILDING RULES
A Modern Duel Commander game is played between two players exactly, who are each other's opponent.
The deck has to be made of 100 cards, ninety-nine as the starting library, and one as the commander.
Modern Duel Commander games don’t use sideboards.
The deck has to be made of unique copies of every cards based on their English name, except for basic lands (Mountain, Forest, Plains, Island, Swamp, Wastes, “basic land” is written on it, which includes snow-covered basic lands). That also applies to the commander.
Any playable Magic: The Gathering card from a Modern-legal set is allowed, except for those that are banned by the Rules Committee for balance reasons.
The commander should be a Legendary Creature card or a card that explicitly states that it can be played as a commander.
The commander defines the colors of the cards in the deck. The only colors authorized in a deck are from every colored mana symbol in the commander card (casting cost and abilities, except from mana symbols in italic text anywhere on the card).
Playing in the format
You play a Modern Duel Commander game pretty much like a regular Magic: The Gathering game, excepted:
Players start with their commander in the command zone.
Players start with a life total of 20. There is no commander damage rule in this format.
Players may play their commander from the command zone by paying their casting cost whenever they would normally be playable.
Commanders can be casted from anywhere they would be legally cast in addition to the command zone.
Every time a player plays a commander from the command zone, the next time they play it again, they will have to pay two generic mana (often written “{2}”) more than the last time they paid to cast it. This only applies to the times it’s cast from a command zone. If you cast your commander from any other zone, like your hand, it only costs its normal casting cost, and does not add two more mana to the casting cost you’d pay the next time you’d cast it from the command zone.
If a commander goes to the graveyard or exile, the player can choose to put it back to the command zone after it ends up there. If a commander would go to the hand or library from anywhere, the player can send it back to the command zone instead. The player can also choose to let it go to the zone it would normally go.