If a player or permanent has more than one kind of counter on it, and you choose for it to get additional counters, it must get one of each kind of counter it already has. You can’t have it get just one kind of counter it already has and not the others.
Players can respond to a spell or ability whose effect includes proliferating. Once that spell or ability starts to resolve, however, and its controller chooses which permanents and players will get new counters, it’s too late for anyone to respond.
You can choose any permanent that has a counter, including ones controlled by opponents. You can choose any player who has a counter, including opponents. You can’t choose cards in any zone other than the battlefield, even if they have counters on them.
Last observed on Scryfall 2 months ago at $7.70. Over the trailing 90 days the price moved between $7.02 and $8.47 across 98 observations. Cross-checked across TCGplayer, eBay sold, Cardmarket EU, and Star City.
This printing is one of 2 catalogued treatments from SLD — the lineup includes Borderless alongside the standard finish. Across our catalog the Rarix library tracks every variant in the same family so collectors can compare price, scarcity and demand inside a single lineage.
Card #2454 of *Secret Lair Drop*, the set that shipped alongside the January 2026 Secret Lair Drop release.
Card type: Instant, color identity green/blue, printed at rare. Rares occupy the bottom-of-pack rare slot in standard boosters. Mana cost: {1}{G}{U} (3 converted). Keyword abilities: Proliferate.
Legal in Legacy, Vintage, and Commander.
EDHrec ranks this card #1,953 in Commander, putting it in the common-include tier of the format's playable pool.
Illustrated by Nicholas Gregory. Rarix catalogs 433 other cards credited to this artist.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Nicholas Gregory
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
Some spells and abilities that cause you to proliferate may require targets. If each target chosen is an illegal target as that spell or ability tries to resolve, it won’t resolve. You won’t proliferate.
You don’t have to choose every permanent or player that has a counter—only the ones you want to add counters to. Since “any number” includes zero, you don’t have to choose any permanents at all, and you don’t have to choose any players at all.
The set of permanents affected by Mutational Advantage is determined at the time Mutational Advantage resolves. Permanents that gain counters later in the turn won’t become affected by this effect, and permanents that lose all of their counters later in the turn won’t stop being affected.
