Karn's Temporal Sundering — ruling 1

If the target player or target nonland permanent is an illegal target as Karn’s Temporal Sundering resolves, the other target is affected as normal and Karn’s Temporal Sundering is exiled. If both targets are illegal, Karn’s Temporal Sundering doesn’t resolve and isn’t exiled.

Karn's Temporal Sundering — ruling 2

You can’t cast a legendary sorcery unless you control a legendary creature or a legendary planeswalker. Once you begin to cast a legendary sorcery, losing control of your legendary creatures and planeswalkers won’t affect that spell.

Karn's Temporal Sundering — ruling 3

Other than the casting restriction, the legendary supertype on a sorcery carries no additional rules. You may cast any number of legendary sorceries in a turn, and your deck may contain any number of legendary cards (but no more than four of any with the same name).

Karn's Temporal Sundering : règles, fonctionnement et interactions (MTG)

Karn's Temporal Sundering 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

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.) Target player takes an extra turn after this one. Return up to one target nonland permanent to its owner's hand. Exile Karn's Temporal Sundering.

Complete guide

Karn's Temporal Sundering is a powerful legendary sorcery that allows you to manipulate time itself. By harnessing the history of Dominaria, you can seize an extra turn while clearing a path through your opponent's defenses. It is a high-impact spell that requires a legendary presence on your board to function.

Casting Requirements

As a legendary sorcery, you cannot even begin to cast this spell unless you control at least one legendary creature or planeswalker. Once the spell is cast and on the stack, it no longer matters what happens to your legendary permanents; the spell will resolve even if your legendary creatures or planeswalkers leave the battlefield before it finishes.

Step-by-Step Resolution

First, you choose a target player and up to one target nonland permanent. When the spell resolves, the chosen player gains an extra turn immediately following the current one. Simultaneously, the targeted nonland permanent is returned to its owner's hand. Finally, as the last part of its effect, Karn's Temporal Sundering is moved to the exile zone instead of the graveyard to prevent easy recursion.

Handling Illegal Targets

Because this spell has two separate targets (a player and a permanent), it behaves specifically if one disappears. If the permanent is removed before resolution, the player still gets their extra turn. However, if all chosen targets become illegal (for example, the player gains hexproof and you chose no permanent), the spell is countered by the rules and goes to the graveyard instead of being exiled.

When to Cast

Timing is everything. Since this spell costs six mana and requires a legend, it is best used when you can capitalize on the tempo swing. Bouncing a blocker and taking an extra turn can often end the game, but be mindful of your opponent's open mana, as a single counterspell can stall your momentum.

Interaction examples

Managing the Hand

Sea Gate Restoration // Sea Gate, Reborn

After casting Karn's Temporal Sundering to take an extra turn and bounce a threat, you can use that extra turn to cast Sea Gate Restoration // Sea Gate, Reborn. This allows you to draw a massive amount of cards and remove your maximum hand size, ensuring you have the resources to win during your bonus time.

Clearing the Board

Raise the Palisade

If you are facing an army of tokens, you can use Karn's Temporal Sundering to target the opponent's most dangerous nonland permanent and gain an extra turn. During your extra turn, you can follow up with Raise the Palisade to clear the rest of their creatures, leaving them with an empty board while you continue your assault.

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

How it works : Karn's Temporal Sundering

Original English text — Wizards of the Coast / Scryfall

#1April 27, 2018· Wizards of the Coast
If the target player or target nonland permanent is an illegal target as Karn’s Temporal Sundering resolves, the other target is affected as normal and Karn’s Temporal Sundering is exiled. If both targets are illegal, Karn’s Temporal Sundering doesn’t resolve and isn’t exiled.
No other card is named in this ruling.
#2April 27, 2018· Wizards of the Coast
You can’t cast a legendary sorcery unless you control a legendary creature or a legendary planeswalker. Once you begin to cast a legendary sorcery, losing control of your legendary creatures and planeswalkers won’t affect that spell.
No other card is named in this ruling.
#3April 27, 2018· Wizards of the Coast
Other than the casting restriction, the legendary supertype on a sorcery carries no additional rules. You may cast any number of legendary sorceries in a turn, and your deck may contain any number of legendary cards (but no more than four of any with the same name).
No other card is named in this ruling.