Reid’s Guide to Legacy: Using Cantrips Properly

My goal with this guide over the coming weeks is to paint a picture of the Legacy format, and today we are going to focus on a very important part of the process – casting cantrips for maximum value.

Table of Contents

Part I: An Introduction to Legacy
Part II: The Defining Cards of Legacy
Part III: Choosing Your Deck
Part IV: Using Cantrips Properly
Part V: Graveyard Decks

Legacy Guide Part IV: Using Cantrips Properly

This installment of my guide will focus on the most important aspect of Legacy. This is not metagaming, or deckbuilding, or sideboarding, or mulligans. It’s the gameplay, which is complex and highly challenging, and also happens to be the reason that Legacy is so beloved by its fanbase. 

For all of the fun and unique parts of Legacy’s gameplay, the one that makes it feel the most different from Magic’s other formats is the card selection. Brainstorm and Ponder, combined with shuffle effects, give players the feeling that their whole libraries are involved in the game, rather than just the cards in their opening hands. Because of these spells, the number of small decisions in a single game of Legacy is astronomically high, and you tend to have a lot of agency over the direction in which things go.

So as a way of capping off this series, let’s discuss the best way to use Legacy’s cantrips, and how to make sure you’re navigating towards a win as often as possible.


Brainstorm’s power comes in pairing it with ways to shuffle your library. Putting back two cards and spending a few turns drawing them again is merely “good,” while sculpting your hand and shuffling away unneeded cards can be gamechanging. 

Brainstorm becomes more powerful as the game goes deeper. You have more information about what cards you need and don’t need (for example, excess lands), and you can more conveniently pair it with a shuffle effect. A midgame Brainstorm to draw three, put back two unneeded cards, and shuffle them away immediately is what legendary commentators Cedric Phillips and Patrick Sullivan have named “a perfect Brainstorm.” The perfect Brainstorm is an excellent technique, and is one that you should work hard to execute, even if it means being a little extra patient in the early turns. 

Note that you can’t execute a perfect Brainstorm on the first turn of the game, and can rarely do it at the end of the opponent’s turn. Often the best time to cast your Brainstorm is on your own mainphase, before you make your land drop. This gives you an influx of new resources to use on your turn, and let’s you best decide how and when to shuffle.

On the opposite extreme from the perfect Brainstorm is the “Brainstorm lock.” This occurs when you have no way to shuffle, and get stuck with nothing to do (perhaps no land drop to make) while you wait to draw through the two cards you put back. This can be devastating in a close game, and is something you should strive to avoid. 


Ponder can also be paired with shuffle effects. This is nice because it gives you flexibility to decide whether you want one, two, or all three of the cards you see. However, you don’t need to worry about casting Ponder on a turn where you can’t shuffle your library, like you would worry with Brainstorm. 

Ponder is the best cantrip for sculpting, and often makes for a very nice turn 1 play. This is because it allows you to see a healthy number of cards, and to take more than one of them. Crucially, it lets you take them in an order of your choosing. For example, you might Ponder and see a high-value card like Show and Tell, but you might prefer to set your hand with a Force of Will or a land while you wait to draw Show and Tell a turn or two from now. 


Preordain is ideal for digging to particular cards. This is why you see Preordain often in combo decks, but less often in fair decks like Delver or Snow. Like Brainstorm, Preordain gets more powerful as the game goes deeper, since you’ll have a clearer picture of what cards you’re looking for. 

Sequencing Your Cantrips

In normal circumstances, Brainstorm should be the last cantrip you play. When things are going well, you can gain value by waiting a little longer. When things are getting dicey–like if you’re missing your land drop–then you should fear getting Brainstorm locked. 

An exception is if you want to use Ponder or Preordain to clear the top of your library after you Brainstorm. This isn’t the default way of doing things, but can be useful if your life total is too low to use a fetchland, or if your opponent has something that’s stopping you from shuffling. It could also come up if you have knowledge of the top of your library and want to draw those cards before the top of your library changes. 

If things are going well, you should cast Arcum’s Astrolabe or any other “blind draw” effects first, saving your more powerful cantrips for later. This is because effects without card selection do not get more powerful as the game goes long. Effects with card selection do, because you have more information about the relative value of the cards you see. 

If you really need to find something specific, like a land or a Force of Will, you can always feel good about using a Ponder. To recap, Ponder is ideal for sculpting your hand at any point in the game, including the early turns. 

When to be Patient

Be patient when you have the luxury to do so. This means that if you have everything you need, and the game is shaping up to continue for a long time, you can hold your cantrips. 

If you’re at risk of missing land drops; if you’re under pressure from an unanswered threat; if the game is likely to go fast; or if mana is likely to be an important resource, then you should usually cast your spells. 

Imagine, for example, that you’re playing against Sneak and Show. When they go for their combo, you can always cast a Brainstorm in response to look for a permission spell. However, Sneak and Show is a deck that can play with any combination of Daze, Spell Pierce, and Flusterstorm. You might not want to spew off mana on the turn of a critical permission battle. If you anticipate mana being tight on a future turn, that can be a good reason to cast your spells when you have a good opportunity to do so. 

Additionally, if there’s a risk of your cantrips losing value, then you may not want to hold them for too long. For example, if your opponent has Chalice of the Void, Narset, Parter of Veils, Leovold, Emissary of Trest, or any other cards that might impact your ability to cantrip later in the game, then you should avoid getting stuck with several still in your hand once those hate cards hit the battlefield.

Force of WillForce of Negation

If you’ve navigated well, the game might get to a point where you have everything you need, plus a Force of Will or Force of Negation in your hand. At this point, you might decide not to cast your cantrip at all, since its best use becomes paying the alternate cost of these permission spells. You metaphorically “staple” your Ponder to your Force of Will to ensure that you won’t be caught without the ability to counter your opponent’s key spell.

Of course, you can always re-evaluate as the game goes on. What you want to avoid is casting your Brainstorm on autopilot and getting unlucky to see three non-blue cards. I’ve seen too many games be decided in this fashion, and you don’t want to be careless.

Stacking the Top of Your Library

A particularly beautiful thing about the blue cantrips is the ability to set a key card on top of your library. Against Thoughtseize and other discard effects, your best spells can be safer on top of your library than they are in your hand. Brainstorm can even be used as a way to counter or reduce the effectiveness of opposing discard spells. 

Pay close attention to the order you draw your cards and leave as few vulnerabilities as possible. That said, be aware that opposing cards like Jace, the Mind Sculptor and Surgical Extraction can change the top of your library against your will. There are no easy answers, and that’s part of the fun!

Example 1

You’re playing a Delver of Secrets deck, you’re going first against an unknown opponent. Your hand is:


Volcanic IslandScalding TarnPonderBrainstormLightning BoltDreadhorde ArcanistDreadhorde Arcanist

This is a bread and butter situation where you should lead with Volcanic Island and Ponder. Ponder is perfect for sculpting your hand, while Brainstorm gets stronger later in the game. With this hand, you probably won’t cast your Brainstorm until turn 3 or turn 4. Save the Scalding Tarn to shuffle later, when you have some knowledge of the top of your library. 

Example 2

You’re playing a Snow Control deck, you went first, played a Snow-Covered Island, and passed the turn. Your hand is:


Flooded StrandMisty RainforestBrainstormIce-Fang CoatlOko, Thief of CrownsJace, the Mind Sculptor

Example 2A: Your opponent uses Polluted Delta for a basic Island, casts Preordain, and scries both cards to the top, then plays a Lotus Petal.

Recall that Preordain is substantially more common in combo decks than in fair decks. The basic (non-Snow) Island and the Lotus Petal also fit the mold of a combo deck. Here, you should worry about the game being compressed to a very small number of turns. 

I recommend Brainstorming at the end of the opponent’s turn, because you don’t want to lose the game before casting your spells. You can see three new cards, untap, draw, and shuffle something away with a fetchland. If you haven’t found a better play, you still have Ice-Fang Coatl to flash in on turn 2. This helps you progress your gameplan the fastest while helping you dig to a crucial Force of Will or Force of Negation.

Example 2B: Your opponent plays Snow-Covered Island and Arcum’s Astrolabe.

In this alternative example, you’re playing a snow mirror, where the game is likely to go long and be very grindy. 

In this case, I recommend untapping without casting your Brainstorm. Your hand is already good, with land drops and solid plays for the next couple of turns. You’re not looking for anything in particular, and you have the luxury of being patient. You might as well let the game develop a little, and your Brainstorm might be more powerful later on. 

Example 3

You’re playing your Sultai homebrew against MonoRed Prison. Your opponent has a Blood Moon, but not much other pressure. On the battlefield you have an Island, a Noble Hierarch, and two dual lands (which are now Mountains). Your hand is:

Polluted DeltaBayouBrainstormPreordainLiliana of the Veil

The situation isn’t an emergency. You’re not under dire pressure, and you’re not digging to one card in particular. You probably have more basic lands, Noble Hierarchs, blue cards, and green cards that might be helpful to draw. Your goal is to improve the overall quality of your hand as much as possible.

Default sequencing would be to cast Preordain first and to wait as long as possible on Brainstorm. However, in this case, I recommend deviating from that and casting Brainstorm first. The reason is that your opponent’s Blood Moon has shut off your ability to shuffle. So the best way to improve the quality of your hand is to Brainstorm, put two of your unusable cards back, and then clear the top of your library with the Preordain. Your top priority is to avoid getting Brainstorm locked, which might give your opponent the time they need to find a threat or tighten their lock on the game.

Even after a decade with Legacy, you’ll continue to learn new techniques and subtleties each and every time you play. Come back next week as I continue unraveling one of Magic’s most intricate and fun formats!


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