Arena Standard

Arena Standard also known as Best-of-one Standard (or Bo1 Standard) is a Magic Arena-specific constructed format of Magic: The Gathering.

Description
As its name suggests, it is a Standard variant played in Magic Arena. Even though in practice, it is slightly different to Bo3 Standard (known as Traditional Standard in Magic Arena) with the following differences:


 * A selected number of exclusive cards from Magic Arena are considered legal in this format.
 * Arena Standard used their own banned list in addition to Traditional Standard's banned list.
 * Starting hands are randomized in a way that should reduce the frequency of mulligans, but without incentivizing mana base construction outside the strategic norms of the game. Wizards feel this achieves the desired effect of reducing the frequency of mulligans without changing how players build their mana bases. The only concrete statement regarding the shuffler was released during closed beta play, and in the updates, since it has been unclear whether the algorithm has changed.
 * The system during the beta drew an opening hand from each of two separately randomized copies of the decks and leaned towards giving the player the hand with the mix of spells and lands (without regard for color) closest to the average for that deck. This formula usually yielded three lands in ones' starting hand because 22÷60×7≈2.567 and 30÷60×7=3.5.
 * You can then use the London Mulligan rules to get a new hand with one fewer card. Mulliganed hands are created from a single randomized draw.

As matches consist of only one game, the sideboard is used for cards with abilities referencing "outside the game", such as Companions and Mastermind's Acquisition. As of April 15, 2021, best-of-one sideboards are restricted to seven cards.

Banned cards
Traditional Standard's banned card, by default, is also banned in Arena Standard.

As of May 15, 2020, no additional card is banned in the current Arena Standard.

Previously banned cards
The following is a list of cards that have been banned in Arena Standard, but not banned in Traditional Standard otherwise, at one point during their stay in the Standard environment.


 * Nexus of Fate
 * Rampaging Ferocidon