Prologue to Phyresis is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Each opponent gets a poison counter. Draw a card.

Complete guide

Prologue to Phyresis is a streamlined blue instant that sets the stage for a victory through toxic means. It serves as both a political tool in multiplayer games and a consistent way to progress your win condition while keeping your hand full. By spreading infection across all opponents simultaneously, you ensure that no one is safe from the creeping corruption.

What It Does

Prologue to Phyresis has two distinct effects that occur in the order they are printed on the card. First, every player designated as your opponent receives exactly one poison counter. Following this, you draw one card from your library. This spell does not target any players or objects, meaning it can bypass effects that grant players hexproof.

How It Resolves Step by Step

When you cast Prologue to Phyresis, it is placed on the stack. If no players respond with spells like Counterspell, the resolution begins. Step one: identify all opponents in the game; each of them gains a poison counter simultaneously. Step two: you draw a card from your deck. Step three: the spell is finished resolving and is placed into your graveyard.

Common Mistakes

A frequent error is assuming this spell targets a specific player. Because the text says 'Each opponent,' you do not choose targets, and the spell cannot be redirected to yourself or a teammate. Additionally, remember that according to the rules for Poison Counter, a player does not lose the game until they have ten or more counters; Prologue to Phyresis provides only the first (or next) step toward that total.

When to Play It

As an instant, the best time to cast this is often at the end of an opponent's turn. This allows you to keep your mana open for reactive plays. It is particularly effective in decks that utilize the Proliferate mechanic, as it provides the initial Poison Counter required to start increasing that count with subsequent spells and abilities.

Interaction examples

Starting the Infection

Poison Counter

You cast Prologue to Phyresis during your opponent's end step. As it resolves, your opponent receives their first Poison Counter. Even though it is only one counter, they are now 'poisoned,' which may enable other abilities in your deck that check for poisoned players.

The Counterspell Confrontation

Counterspell

If you cast Prologue to Phyresis and your opponent responds with Counterspell, the entire effect of your spell is negated. You will not give any poison counters to your opponents, and you will not draw a card, as the spell never resolves.

Trading Corruption for Treasure

An Offer You Can't Refuse

If you cast Prologue to Phyresis and it is targeted by An Offer You Can't Refuse, your spell is countered. While you lose the poison application and the card draw, the resolution of the countering spell grants you two Treasure tokens, which can be used for mana later.

Guide written with AI from the official text and rulings. Official English text prevails.