Of the more widely played formats in Magic: The Gathering, Vintage allows players to choose from the largest card pool when constructing their decks. However, some of those cards are considered so powerful that only a single copy is allowed per deck – and among those, Brainstorm is one of the most popular. In Legacy where Brainstorm is allowed as a four-of, the card is a returning subject when possible bannings are discussed.
From its humble beginnings as a somewhat overlooked Common in Ice Age (June 1995) and scoffed at for not being the new Ancestral Recall, Brainstorm has come a long way. Today, the card is not only a staple in Legacy, but it is also widely regarded as the card that defines the format. MTG Top 8 has even it ranked as the most played card in Legacy with between 50.00 - 60.00 % of all players maindecking a full playset.
Depending on which statistics you look up for Vintage, the single copy of Brainstorm allowed in that format is put in around half of all decks played competitively, plus/minus 5.00 %. Aside from members of the exclusive Power Nine, very few cards such as Sol Ring, Mana Crypt and Force of Will can compete with the pervasiveness of this card.
In Pauper where Brainstorm is also legal, its popularity is a lot lower since the format does not have access to fetch lands. Fetch lands allow players to shuffle away less useful cards from their hand and avoid what is commonly known as a "Brainstorm lock", wherein the player ends up having to spend their following two draws drawing the unwanted cards. Where Brainstorm can make it into just about any deck in Vintage and Legacy for its ability to help smooth out draws or hide important combo pieces when targeted by discard spells, the card's application in Pauper is more limited. Its use is often restricted to decks looking for cheap cantrips, such as U/R Delver.
While Brainstorm's effect is straightforward and understandable even for Magic beginners, its true power comes from its ability to instantly draw three cards then put two cards from your hand on top of your library. This gives players a firmer grasp and better familiarity with the finer nuances of the game. Brainstorming correctly in any given situation and holding off on Brainstorming is almost an art. Many articles have been written exploring how to perfectly play the card.
As a Common in Ice Age, Fifth Edition (March 1997), and Masters 25 (March 2018) among other reprints, most versions of Brainstorm cost less than 0,50 €. Even its printing in Signature Spellbook: Jace (June 2018) is easily available at 1,00 € or less in near mint condition. Only the Friday Night Magic Promos (February 2000) version is a price outlier and could be an object of interest as its price fluctuates around the mid-thirties.