A while back I posted about the basic rules of Magic. If you’ve read that, you should have a pretty good idea about how a turn goes, what creatures do, et cetera. Now you want to play an actual game. You’ve heard that Commander is a casual format, and you kind of like the idea of just sitting around the kitchen table with your friends, playing whatever cool cards you can get your hands on. Maybe your brother-in-law used to play and donated his collection to you when he heard you were interested in the game. Now you want to put together a deck.
If you don’t have an extensive collection of cards, you might want to refer to my post about budget deck-building. Or you could just buy one of the pre-constructed decks. If you want to build your own deck, there are some rules specific to the Commander format that you need to be aware of.
First, color identity. Your commander’s color identity includes all mana symbols found anywhere on the card, excluding reminder text. For instance, while Bosh is a colorless creature, because there is no colored mana in his mana cost, he has a red activated ability, which makes his color identity, for the purpose of Commander, mono-red. Rhys the Exiled is a mono-green creature, but his black activated ability means that his color identity is green-black. Note: You are allowed to run Bosh (Bosh, Iron Golem) or Rhys as your commander. Because Bosh has red in his color identity, you would be running a mono-red deck; with Rhys, it would be a green-black deck. Hybrid mana counts as both colors that it could be; Daghatar the Adamant, for example, is a white-green-black commander.
You are only allowed to run cards that are in your commander’s color identity. This includes basic lands. According to the rules of Commander, you can’t run basic lands that would produce mana outside your commander’s color identity. Likewise, you can’t run any guildgates in your Bosh deck, because they all have mana symbols that are outside your commander’s color identity. You can, however, run lands that say they tap for any color of mana, as long as the actual mana symbols don’t appear anywhere on the card. There used to be a rule that if you tried to tap a land for a color not in your commander’s color identity, it would produce colorless instead; with the advent of cards that require colorless mana in casting or activation costs, this rule has gone away. Hybrid mana, again, counts as both colors of mana. You can’t run a Dominus of Fealty in your mono-red Heartless Hidetsugu deck, because Dominus is both red and blue, at the same time.
Now that you understand how color identity works, you can choose your commander. Your commander has to be a legendary creature. Any legendary creature will do, as long as it’s not banned in the format. (You can find the updated Commander banned list here.) You start the game with your commander in the Command Zone, and can cast it from the Command Zone on your main phase (or at any point if it has flash, like Yeva) as soon as you have the mana to cast it. Since you are guaranteed to have access to your commander, and its color identity dictates what you can and cannot put in your deck, choosing your commander can be the most important decision you make when constructing your deck.
Commander is often referred to as a hundred-card singleton format. What this actually means is that, including your commander, you have a total of one hundred cards, and you are only allowed to run a single copy of each of those cards, the exceptions being basic lands, and cards that specifically say you can run multiple copies, like Relentless Rats (because card text trumps game rules).
Once you have your deck, you’re ready to start playing. Each player starts at 40 life (as opposed to the usual 20 for most formats). Commander is generally a multiplayer format; I recommend four players minimum. You can play with only two, although there is a different banned list for two-player; but part of the beauty of Commander is that if all parties agree to ignore the banned list, that’s fine, because you’re just playing to have fun. Three players is technically multiplayer, but what often happens is that the two players with weaker decks will gang up on the player with the stronger deck, which doesn’t tend to be very fun.
You can roll a die to determine who goes first. After the first player, proceed around the table in a clockwise fashion. Since it’s multiplayer, the first player does draw a card on his or her first turn (for two-player Commander, as with most formats, the first player does not draw a card on his or her first turn). Also because it’s multiplayer, the first time you mulligan it’s “free,” that is, you go back to seven rather than immediately down to six. (Subsequent mulligans do decrease the number of cards.)
For the most part, Commander is the same as other formats, with a few exceptions. As already noted, you start at 40 life, rather than the usual 20. Priority is passed around the table in turn order, which usually isn’t relevant to know, unless you want to know who gains possession of a sacrificed creature when there are three copies of It That Betrays on the battlefield. (What is the proper plural of It That Betrays? Its That Betray? They That Betray?)
The main thing that distinguishes Commander from other formats is your commander itself. As previously mentioned, your Commander hangs out in the Command Zone until you’re ready to cast it. If your Commander would change zones, you can choose to send it back to the Command Zone rather than whatever zone it would go to (hand, library, graveyard, exile), so it will be available for you to cast again later. The only catch is that, for each time you’ve already cast it from the Command Zone this game, you have to pay a “commander tax” of two mana. So, if you’re running Olivia Voldaren as your commander, the first time you cast her, she costs two, a red, and a black, for a total of four. If she gets killed, you can send her to the command zone rather than the graveyard (which incidentally will not trigger any effects that happen when a creature dies, or if a creature died this turn, since she never actually hits the graveyard); later you can cast her again for four, a red, and a black, or a total of six. If she then gets exiled (Olivia is a scary commander, and clearly your opponents have been following my advice and running removal), you can again send her to the command zone. At that point, the next time you want to cast her, you’ll have to pay six, a red, and a black, for a total of eight. If, however, someone casts Cyclonic Rift overloaded, and she gets bounced to your hand, you can choose either to send her to your hand or to the Command Zone; if she goes to your hand, you can cast her from your hand for her original mana cost. If she dies again, or if someone counters her when you try to cast her, and you send her back to the Command Zone, she’ll cost eight, a red, and a black, since commander tax keeps track of how many times she’s been cast from the Command Zone this game. Keep in mind that this is a choice; if you have a way to reanimate your commander from your graveyard, by all means, let your commander stay in your graveyard. If your commander then gets exiled from your graveyard, you can at that point choose to send it to the Command Zone instead. If you’re running Obzedat, Ghost Council as your commander, and want to use his ability to exile him at your end step and return him on your next turn, you’re welcome to do so.
In addition to whatever cool effects you can get from whatever abilities your commander has, you can also kill your opponents with commander damage. If a player takes a total of twenty-one (or more) combat damage from a single commander over the course of the game, that player loses the game. This applies to combat damage only; Ruric Thar, the Unbowed‘s ability that deals 6 damage when a player casts a non-creature spell will not add to the total. Also, it’s not the total combat damage taken from all commanders; if you’ve taken eleven combat damage from Olivia Voldaren and twelve from Ruric Thar, you’re still in the game. And keep in mind that you can die to damage from your own commander; I once almost died to my own Sliver Legion because the Lorthos, the Tidemaker player had tapped down all my creatures, and the next player stole Sliver Legion for the turn and swung it at me. Luckily I was able to flash in Quick Sliver and save myself.
And that’s about it. If you have any questions, feel free to leave them in the comments.