Opus in MTG: Rules, History, and Best Cards

Last updated on April 24, 2026

Colorstorm Stallion | Illustration by Lorenzo Lanfranconi

Our first semester at Strixhaven introduced the magecraft mechanic, a spellslinger value engine that rewards you for engaging with magic at its most basic. But Secrets of Strixhaven has advanced our studies with five new mechanics that better embody what each college teaches.

The Prismari school () gets a mechanic similar to magecraft in opus, which also cares about casting instants and sorceries, and it loves when you get flamboyant with expensive ones. Let’s break down what this mechanic does and how to use it!

How Does Opus Work?

Spectacular Skywhale | Illustration by Serena Malyon

Opus is a triggered ability that appears on red, blue, and blue-red cards aligned with the Prismari school in Secrets of Strixhaven. Opus triggers whenever you cast an instant or sorcery spell and provides an initial effect, then has an additional effect if you spent 5 or more mana to cast the spell.

One of the coolest examples is Colorstorm Stallion. Whenever you cast any instant or sorcery, it gets +1/+1, kinda like prowess. But if you spent 5 or more mana, you also get a token copy. It’s important to note this isn’t an either/or scenario; you get both effects.

The History of Opus in MTG

The roots of opus are in Strixhaven: School of Mages, on Prismari Apprentice and Spectacle Mage. Prismari cards that reward you for big instants and sorceries pair nicely with the school’s love of flamboyant, expressive magic, so it makes sense that niche would be expanded in Secrets of Strixhaven.

Secrets of Strixhaven gave opus the name and made it a central part of the school’s identity rather than put it on a throwaway uncommon. Opus cards can be found at all rarities and give Prismari a more concrete identity rather than being just another magecraft synergy.

Does Opus Care About the Mana Value of Spells?

No. Opus only cares about the amount of mana spent to cast a spell. Take this example: You want to cast Memory Deluge but your opponent controls Thalia, Guardian of Thraben. You’d have to spend 5 mana on it, and would thus trigger opus’s bonus ability. This also applies when you pay additional or alternative costs on cards like Rite of Replication and Cyclonic Rift.

On the flipside, this means large spells you cast for reduced mana costs might not count. For example, a Time Warp that you cast for 4 mana with the cost reduction from Goblin Electromancer doesn’t trigger opus. Similarly, effects like Mizzix's Mastery that cast spells without paying their mana cost won’t trigger opus’s additional effect because you don’t spend mana to cast it.

Do Copied Spells Trigger Opus?

Almost never. If you copy a spell on the stack, the copy doesn’t count as being cast, so you won’t get either part of the opus effect.

Some cards let you cast copies of spells instead of copying them on the stack; Mizzix's Mastery is a great example. If those spells let you cast the spell “without paying its mana cost,” then they’ll trigger the opus ability but won’t get the bonus effect since you spent no mana. If you can cast a copy while paying mana, like with a prepared spell, you can trigger opus and get the bonus ability. The key part is to spend 5+ mana on the spell.

Does Opus Trigger on X-Spells?

X-spells always trigger opus’s first effect and provide the bonus effect as long as you spend 5 or more mana to cast the spell. Notably, opus doesn’t care about the value of X, just the total amount mana you’ve spent on the entire spell.

Did Opus Replace Magecraft?

You could see it that way, though opus isn’t the only “replacement” mechanic in this sense. The collective of opus, increment, repartee, and infusion have replaced magecraft with mechanics that provide a deeper flavor connection to their respective schools. Lorehold simply got flashback and retains an identity that cares about when cards leave the graveyard.

Gallery and List of Opus Cards

• Colorstorm Stallion
• Deluge Virtuoso
• Elemental Mascot
• Exhibition Tidecaller
• Expressive Firedancer
• Molten-Core Maestro
• Muse Seeker
• Spectacular Skywhale
• Tackle Artist
• Thunderdrum Soloist

Best Opus Cards

Colorstorm Stallion

Colorstorm Stallion hits hard and brings along some friends. It might be the flashiest opus card, which makes it an excellent fit for Prismari and Commander. Notably, the copies can copy themselves, so the herd takes over games quickly if you have the mana to spend.

Exhibition Tidecaller

Exhibition Tidecaller has incredible mill potential, offensively and synergistically. Honestly, it might be better to use this to mill yourself and set up cards like Mizzix's Mastery and Yawgmoth's Will than to try and get your opponents; mill decks often rely on bigger bursts of mill from cards like Mesmeric Orb and Tasha's Hideous Laughter.

Molten-Core Maestro

Molten-Core Maestro has a fine trigger without the opus bonus. A steadily-growing menace threat that comes down early poses lots of problems for your opponent. The bonus ability is the reason to play the card, however. Notably, opus isn’t restricted to one trigger per turn. If you trigger opus and make 5+ mana, then you can use it to cast another spell, retrigger opus, and so on. That could even go infinite with the right setup!

Wrap Up

Brush Off | Illustration by Genel Jumalon

Opus looks like a lot of fun. It’s a pretty simple mechanic but it comes with interesting uses and synergies since it cares about the amount of mana you spend rather than the mana value of the spell you cast. While the flavor’s tied to Prismari, it’s also neutral enough that I could see it pop up here or there in the future, and I wouldn’t mind to see it resurface.

Do you like opus? Do you wish Wizards had stuck to magecraft? Let me know in the comments below! If you want more Secrets of Strixhaven coverage, check out Draftsim’s YouTube channel, The Daily Upkeep!

Stay safe, and thanks for reading!