Boast in MTG: Rules, History, and Best Cards

Last updated on July 29, 2026

Arni Brokenbrow | Illustration by Dmitry Burmak

The plane of Kaldheim takes heavy inspiration from Norse mythology. During the times of the Norse, stories of great battles would sweep through the lands by word of mouth. Warriors would boast of their great achievements as they sat by campfires over food.

To incorporate that same flavor into Kaldheim, we have the boast mechanic. It’s no longer exclusive to just that plane, but the ability still captures that Norse feel of telling grandiose stories about one’s accomplishments.

So let’s take a look at this mechanic and how it carries over mechanically to the game of Magic.

How Does Boast Work in MTG?

Sigurd, Jarl of Ravensthorpe | Illustration by Alexander Gering

A boast ability is an activated ability that can only be activated if the creature with the ability attacked that turn. These abilities can only be activated once per turn. You can activate boast at any time during your turn after attacking with a boast creature, including in the declare attackers’ step before blocks.

The History of Boast in MTG

Boast first appeared as a main mechanic in 2021’s Kaldheim. It appeared on 17 cards in the set, mostly centered in Mardu colors (), with one green card and zero blue cards.

The mechanic appears sporadically on one-off designs outside Kaldheim, and it has been used a couple times on particularly pompous Universes Beyond characters like Baron Helmut Zemo and Sigurd, Jarl of Ravensthorpe.

Is Boast an Activated Ability?

Yes, boast is essentially an activated ability with a stipulation on when you can activate it. It uses the stack and can be countered by anything that counters abilities, and it can be copied by effects that copy abilities. Many boast abilities require mana to activate, though cards like Baron Helmut Zemo and Eradicator Valkyrie use other resources for their abilities.

Can You Activate Boast as an Instant?

You can boast at instant speed, or whenever you have priority after declaring a creature with boast as an attacker.

When Can You Boast?

Boast can be activated any time after the declare attacker's step, until the end of the turn. This can be done as a sorcery in your post-combat main phase, or at instant speed during the middle of combat.

Can You Activate Boast Before Blockers? Before Damage?

You can activate boast before or after blockers, as long as it’s before damage. Any time you have priority after a boast creature attacked you can activate boast.

What About After Combat?

You can boast after combat, assuming the creature with boast survived. There are no timing restrictions to boast other than it has to happen after attacking with that creature, and it can only be activated once per turn.

Can You Boast Twice?

You can only activate each boast ability once per turn. But Birgi, God of Storytelling allows you to boast twice per turn rather than just once.

Can You Boast with a Creature that Was Put onto the Battlefield Attacking?

Since the creature was put onto the battlefield attacking, it was never declared as an attacker. You need to declare a creature with boast as an attacker to activate boast so you can’t use boast with a creature that entered attacking.

If You Get Multiple Combats, Can a Creature Boast Twice?

Even if you gain multiple combat steps, you can only boast once. It can be used any time after the first attack is declared.

How Do You Activate Boast in MTG Arena?

You can click on your boast creature after attacking and pay any costs to activate the boast ability. Activating boast works like any other activated ability on MTG Arena.

Gallery and List of Boast Cards

Cards with Boast

• Axgard Braggart
• Battershield Warrior
• Goldmaw Champion
• Usher of the Fallen
• Baron Helmut Zemo
• Draugr Recruiter
• Duskwielder
• Eradicator Valkyrie
• Varragoth, Bloodsky Sire
• Arni Brokenbrow
• Broadside Bombardiers
• Dragonkin Berserker
• Fearless Liberator
• Fearless Pup
• Hagi Mob
• Tuskeri Firewalker
• Horizon Seeker
• Sigurd, Jarl of Ravensthorpe

Cards That Reference Boast

These cards don’t have boast abilities themselves, but reference the ability on other cards.

• Birgi, God of Storytelling
• Frenzied Raider

Best Boast Cards

#4. Sigurd, Jarl of Ravensthorpe

For how often we see sagas in MTG sets, it still feels like we’re lagging behind on viable saga commanders. Sigurd, Jarl of Ravensthorpe gets the job done, with a handful of keywords and the ability to grow your board while manipulating the lore counters on your sagas. You can speed them up, or turn back a chapter to keep repeating the same story over and over.

#3. Baron Helmut Zemo

The boast ability on Baron Helmut Zemo is a thing of beauty. It encourages a fully dedicated mono-black deck with tons of black pips across its cards, and the connive trigger helps you to bin cards to get to the requisite fifteen black pips. Once you see in the ‘yard, you’re one attack away from three free spells.

#2. Varragoth, Bloodsky Sire

Kind of a flavor fail that this demon rogue gives you a Vampiric Tutor instead of a Demonic Tutor, but I suppose the card had to be fair. Deathtouch goes a long way to make sure you’re not just tossing Varragoth, Bloodsky Sire away for your tutor, and there’s even a political edge here since Varragoth can target any player for the tutor.

#1. Broadside Bombardiers

Broadside Bombardiers is just a ludicrous creature that has at times been removed from environments as strong as the Arena Powered Cube for power considerations. Turning Treasures into shocks or warped Nova Hellkites into an additional 7 damage is just absurd damage output for the cost of attacking with a 3-drop haste creature.

Wrap Up

Axgard Braggart | Illustration by Svetlin Velinov

Boast hasn’t quite made the leap to full-set mechanic after being introduced in Kaldheim, but WotC has used it sparingly where it makes sense to do so. The mechanic features on one of the best-ever creatures in Magic (Bombardiers), and incentivizes attacking, which is something the game could always use more of.

All that said, this mechanic really isn’t anything to, well, boast about. The impact of the original cards was fairly muted, and more recent designs have been more flavorful than powerful. There’s room to iterate in the future, but for now boast is hardly in the conversation for anyone’s favorite mechanic.

Which of these cards would you boast about? And what kind of boast abilities would you like to see in the future? Let me know in the comments, or boast about it over in the Draftsim Discord. While you’re here, check out The Daily Upkeep newsletter to stay up to date on all the latest MTG news.

Thanks for making Draftsim your #1 stop for all things Magic!