A lot of game groups impose their personal bans on different strategies, combos, or specific cards to make sure no one makes the game boring for everyone else. The commander damage is also reduced from 21 to 18, and you're able to use your commander’s abilities from the command zone with a tax applying for every time you use them after the first one. You can also sacrifice your opponents’ commanders as long as they’re under your control. This would most likely put them back into their command zone, but it’s still a viable way to remove them from the field and up their cost a bit in the process. In the modified version you set aside all the cards you don’t want and then draw that many cards minus one.
Once I got beyond the basics and was actually looking to build competitive decks, there was one tip that improved my deck building the most, at all levels. I suggest a more control deck or big Creatures deck to be closer to the 45 "land" count and more aggro to the lower end of the range. You can remove 2 mana rocks or a land card if you have a lower curve but always compensate. A lot of people feel like dying to 10 poison counters in Commander is too unfair.
After that, you lose cards for each mulligan as normal. Here I will present some more general information on how many colored mana sources you need in order to cast your spells reliably. The calculations always look at the cases where you have drawn sufficient lands and considers the probability of having the right ones among them. I did not change the numbers of cards in the deck dependent on the number of mulligans.
Commander Format
Mana rocks are usually 3-10, depending on how much mana you need. Seem to be common to run at least a few and the ability to swing the battlefield is obvious. Fill out the rest with a balance of cards, and you'll be well on your way to being a Commander veteran.
Partner Commanders
When I count my lands, I use the following formula. Note that the cards should be able to be cast before turn 4. Steep color requirements like Sign in Blood in a 3 color deck are also problematic. Furthermore, a commander deck 3 mana Commander like “Tymna, the Weaver” blocks the 3 mana slot, so you cannot count these cards either.
You’ll know when this is the case when you’re usually unhappy to see a card instead of happy to see it. If it doesn’t bring you joy, throw it into the nearest wall and choose something else. Almost every successful deck ever has had a plan behind its construction. And now hopefully you can apply this to your own deck building. On the complete opposite end of the spectrum are what are commonly referred to by the wonderfully descriptive name "good stuff" decks. These are decks where you basically pour in a ton of the best cards in the environment until it becomes a bit of deck soup.
After all, Magic is and always will be a social game. Standard Brawl is recognized as an official format, unlike many variants of Commander. Some partners like Jacob Frye and Evie Frye are exclusive and only have one other card they can be paired with in the command zone. Commander is a format with quite a few restrictions when building your deck. I’ve already mentioned a few but I’ll go through them again here.
Playing the Game
Decks that are not very popular or common in the metagame are called rogue decks. The force behind any and all Commander rules is the Commander Rules Committee. This is a group of players and fans of the format, most of them part of the group that created, nurtured, and popularized the format way back when it first started. The official banned list and rules are curated by the CRC, and all decisions they take are officially backed by Wizards.
Then - and this is where it gets good - you can cast that spell if it’s a nonland card. The idea of a "good stuff" deck is nearly the inverse of a linear strategy. These decks play a lot of cards that don't always synergize with each other, hoping that their raw card strength will be enough. If you can match your opponent card-for-card with generally stronger spells, eventually you are likely to come out ahead.
This means that gaining life doesn’t change the damage received from commanders. You might think this is a bit broken, and you’d be right. That’s why a little thing called commander tax exists. Every time you cast your commander, the next time you cast it costs an extra . If your commander has a converted mana cost of three, casting it a second time will cost a total of five mana, and then seven, and so on.
This includes its mana cost, activated abilities, mana production, and any other instances of a colored mana symbol. So, if your commander costs only green to cast, but has an activated ability that costs or produces red mana, then that commander's color identity is both red and green. Then you can remove actual land cards from the deck. Let's see if my commander decks follow these rules. The good thing about hybrid mana cards is that your playgroup might let you run some even if they don’t technically fit your deck’s color identity, especially in mono-colored decks.
A Valki, God of Lies / Tibalt, Cosmic Impostor deck has a color identity of black and red even if the front face of the card is mono-black. This is an example of a commander that has a different color and color identity. Kenrith, the Returned King’s casting cost is and it has five abilities. Each of these abilities requires one mana of each of the five colors in the color pie. This means that Kenrith’s color identity is 5-colored.
Your life total is 40 instead of 20 after all, so it’s only fair that you need extra poison counters to lose. Double-sided cards also opened a really interesting possibility with Extus, Oriq Overlord since you can cast it for its reverse side, Awaken the Blood Avatar. This is the first time in the history of the game that a sorcery can be cast from your command zone. I’ve established that your commander's color identity determines what other 99 cards can go into your deck. This means that the cards’ color identities also need to be the same as your commander's. In the case of commanders with the partner keyword (which I’ll talk about in a bit), you have two cards in your command zone and 98 in your main deck.