Worm Harvest — ruling 1

Casting a card by using its retrace ability works just like casting any other spell, with two exceptions: You're casting it from your graveyard rather than your hand, and you must discard a land card in addition to any other costs.

Worm Harvest — ruling 2

Casting a card with retrace from your graveyard follows the normal timing rules for its card type.

Worm Harvest — ruling 3

When a retrace card you cast from your graveyard resolves or is countered, it's put back into your graveyard. You may use the retrace ability to cast it again. If it's your turn, you may do so before any other player may take actions to try to remove it from your graveyard.

Worm Harvest — ruling 4

If the active player casts a spell that has retrace, that player may cast that card again after it resolves, before another player can remove the card from the graveyard. The active player has priority after the spell resolves, so they can immediately cast a new spell. Since casting a card with retrace from the graveyard moves that card onto the stack, no one else would have the chance to affect it while it's still in the graveyard.

Worm Harvest — ruling 5

Casting a card by using its retrace ability works just like casting any other spell, with two exceptions: You're casting it from your graveyard rather than your hand, and you must discard a land card in addition to any other costs.

Worm Harvest — ruling 6

If you cast Worm Harvest from your graveyard by using retrace, the land you discard as an additional cost will be counted by Worm Harvest when it resolves.

Worm Harvest — ruling 7

A retrace card cast from your graveyard follows the normal timing rules for its card type.

Worm Harvest — ruling 8

When a retrace card you cast from your graveyard resolves, fails to resolve, or is countered, it's put back into your graveyard. You may use the retrace ability to cast it again.

Worm Harvest : règles, fonctionnement et interactions (MTG)

Worm Harvest 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

Create a 1/1 black and green Worm creature token for each land card in your graveyard. Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Complete guide

Worm Harvest is a powerful engine for graveyard-focused decks, turning every extra land in your hand into a swarm of tokens. Because it features the Retrace mechanic, this sorcery is never truly gone, as it can be cast repeatedly from your graveyard.

Understanding Retrace

Retrace is a keyword that allows you to cast the spell from your graveyard. To do this, you pay the mana cost as normal and add one additional cost: discarding a land card from your hand. When the spell finishes resolving, it returns to the graveyard instead of staying in exile or leaving the game, allowing you to repeat the process as long as you have mana and lands to discard.

Resolution Steps

First, you determine how many land cards are currently in your graveyard. If you cast Worm Harvest using its Retrace ability, the land card you discarded to pay the cost is already in the graveyard by the time the spell checks this number. Second, you create that many 1/1 black and green Worm creature tokens. Finally, the sorcery card is placed back into your graveyard, ready to be used again later.

Common Pitfalls

A common mistake is thinking you can cast this at any time. Retrace does not change when you can cast a spell; since Worm Harvest is a sorcery, you can only cast it during your main phase when the stack is empty. Additionally, remember that if an opponent exiles your graveyard in response to you casting it, you still get the tokens based on the lands that were there when the spell resolves, but the card itself won't be in the graveyard to be cast again if it is countered by a spell like Dissipate.

When to Play It

This card is best used in the late game when you have accumulated several lands in your graveyard and have excess lands in your hand that are no longer needed for mana. It provides a constant source of blockers or attackers, ensuring you never run out of threats even if your opponent clears the board.

Interaction examples

Boosting the Harvest

Skyshroud Claim

You cast Skyshroud Claim to pull two Forests from your library to the battlefield, thinning your deck. Later, after those lands are destroyed or if you use other effects to put lands into your graveyard, Worm Harvest will count every Forest and any other land type currently in your graveyard to determine how many 1/1 Worm tokens you create.

Refilling Your Hand

Rishkar's Expertise

If you have several Worm tokens on the battlefield, you can cast Rishkar's Expertise to draw cards equal to the power of your strongest creature. This helps you find more land cards to discard for Worm Harvest's Retrace cost, ensuring the cycle of token creation continues in subsequent turns.

The Retrace Loop

Worm

If you have five lands in your graveyard and discard a land to Retrace Worm Harvest, the spell sees six lands upon resolution. You create six 1/1 Worm creature tokens. Because the spell returns to the graveyard after it resolves, and you are the active player, you have priority to cast it again immediately before an opponent can use an effect to exile it from your graveyard.

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

How it works : Worm Harvest

Original English text — Wizards of the Coast / Scryfall

#1July 13, 2018· Wizards of the Coast
Casting a card by using its retrace ability works just like casting any other spell, with two exceptions: You're casting it from your graveyard rather than your hand, and you must discard a land card in addition to any other costs.
No other card is named in this ruling.
#2July 13, 2018· Wizards of the Coast
Casting a card with retrace from your graveyard follows the normal timing rules for its card type.
No other card is named in this ruling.
#3July 13, 2018· Wizards of the Coast
When a retrace card you cast from your graveyard resolves or is countered, it's put back into your graveyard. You may use the retrace ability to cast it again. If it's your turn, you may do so before any other player may take actions to try to remove it from your graveyard.
No other card is named in this ruling.
#4August 1, 2008· Wizards of the Coast
If the active player casts a spell that has retrace, that player may cast that card again after it resolves, before another player can remove the card from the graveyard. The active player has priority after the spell resolves, so they can immediately cast a new spell. Since casting a card with retrace from the graveyard moves that card onto the stack, no one else would have the chance to affect it while it's still in the graveyard.
No other card is named in this ruling.
#5August 1, 2008· Wizards of the Coast
Casting a card by using its retrace ability works just like casting any other spell, with two exceptions: You're casting it from your graveyard rather than your hand, and you must discard a land card in addition to any other costs.
No other card is named in this ruling.
#6August 1, 2008· Wizards of the Coast
If you cast Worm Harvest from your graveyard by using retrace, the land you discard as an additional cost will be counted by Worm Harvest when it resolves.
Card named in this ruling
Worm
#7August 1, 2008· Wizards of the Coast
A retrace card cast from your graveyard follows the normal timing rules for its card type.
No other card is named in this ruling.
#8August 1, 2008· Wizards of the Coast
When a retrace card you cast from your graveyard resolves, fails to resolve, or is countered, it's put back into your graveyard. You may use the retrace ability to cast it again.
No other card is named in this ruling.