There are digital codes Magic: The Gathering Arena players can use to unlock new in-game booster packs and card cosmetics in the free-to-play digital collectible card game. There's also a code that unlocks two levels in the MTG Arena's Mastery system.
To get cards you need in MTG Arena, you usually need money to spend on gems, the in-game currency of MTG Arena that lets you purchase packs, card styles, pets, and bundles. While players can still buy packs if they want to, they can start off stronger than everyone who doesn't know about the free codes.
Since the digital release of Kaldheim in Jan. 28, players are able to unlock three free Kaldheim booster packs in MTG Arena by entering the code "PlayKaldheim".
You can check out the list of free MTG Arena free non-unique codes below. Note that these codes can only be entered once per account and they have an expiration date. This list will be updated regularly as new codes come and old codes expire.
MTG Arena booster pack codes
When a new Standard-legal Magic: The Gathering set comes out on MTG Arena, Wizards of the Coast usually release a code to unlock three free booster packs, but some older sets that are still Standard-legal no longer have a valid code such as Throne of Eldraine. However, there are still Historic-legal sets that have active codes such as the ones for Ravnica: Allegiance and War of the Spark.
PlayKaldheim (3 KHM booster packs)
TryKaldesh (3 Remastered booster pack)
PlayTheros (3 THB booster packs)
PlayIkoria (3 IKO booster packs)
PlayM21 (3 M21 booster packs)
Play Zendikar (3 ZNR booster packs)
FNMatHome (3 promo pack in conjunction with LGS)
PlayAllegiance (3 Ravnica Allegiance booster packs)
PlayRavnica (3 Guilds of Ravnica booster packs)
PlayWarSpark (3 WAR booster packs)
MTG Arena card style codes
While some older cards still have valid card style codes, some codes have expired sooner such as the ZendikarLands code, which expired before Kaldheim was released in MTG Arena. The expiration dates for the card styles vary; here are the active codes for card styles:
EnlightenMe: Narset, Parter of Veils WAR glass card style
WrittenInStone: Nahiri, Storm of Stone WAR glass card style
ShieldsUp: Teyo, the shieldmage WAR glass card style
InnerDemon: Ob Nixilis, the Hate-Twisted WAR glass card style
OverTheMoon: Arlinn, Voice of the Pack WAR glass card style
ShinyGoblinPirate: Fanatical Firebrand M19 card style
SparkleDruid: Druid of the Cowl M19 card style
FoilFungus: Deathbloom Thallid M19 card style
ParallaxPortion: Revitalize M19 card style
SuperScry: Opt M19 card style
Wizards of the Coast released only one experience code that's currently active. We still don't know when it will expire or if they plan to add new XP codes in the future.
LevelUp: 2,000 XP
Other free MTG Arena codes
There are also codes players can get from Magic products obtained from a local game store that's a part of the Wizards Play Network. There are codes from tabletop prerelease packs, Planeswalker decks, and some MTG in-store events but those unique codes can only be redeemed once. Twtich Prime also also drops loot that contains a code for an MTG Arena deck.
Note that some of these codes are case sensitive, but not all. If the code doesn't work for you and you see an error with a "Redeem Code Failure", then you probably already have redeemed the reward of the code.