Invasion of Ikoria // Zilortha, Apex of Ikoria — ruling 1

You decide whether to assign a non-Human creature’s combat damage as though it weren’t blocked just before it assigns that damage. You may make a different choice for each non-Human creature you control—that is, you may have none, some, or all of those creatures assign combat damage as though they weren’t blocked.

Invasion of Ikoria // Zilortha, Apex of Ikoria — ruling 2

Assigning a creature’s damage as though it weren’t blocked is all or nothing. You can’t use this effect to assign some of the creature’s damage to a blocking creature and the rest to the player, planeswalker, or battle it’s attacking.

Invasion of Ikoria // Zilortha, Apex of Ikoria — ruling 3

Even if a creature assigns damage as though it were not blocked, it will still receive damage from creatures that are blocking it.

Invasion of Ikoria // Zilortha, Apex of Ikoria — ruling 4

Sieges each have an intrinsic triggered ability. That ability is “When the last defense counter is removed from this permanent, exile it, then you may cast it transformed without paying its mana cost.”

Invasion of Ikoria // Zilortha, Apex of Ikoria — ruling 5

As a Siege enters the battlefield, its controller chooses an opponent to be its protector.

Invasion of Ikoria // Zilortha, Apex of Ikoria — ruling 6

A Siege’s controller can’t be its protector. If a Siege’s protector ever gains control of it, they choose a new player to be its protector. This is a state-based action.

Invasion of Ikoria // Zilortha, Apex of Ikoria — ruling 7

If a non-battle permanent that is already on the battlefield become a copy of a Siege, its controller chooses one of their opponents to be that battle’s protector. However, it will most likely be put into its owner’s graveyard because it has no defense counters (see below).

Invasion of Ikoria // Zilortha, Apex of Ikoria — ruling 8

A battle’s “defense” is displayed in the bottom right corner of the card. A battle enters the battlefield with that number of defense counters. If another permanent enters the battlefield as a copy of a battle, it also enters with that number of defense counters.

Invasion of Ikoria // Zilortha, Apex of Ikoria : règles, fonctionnement et interactions (MTG)

Invasion of Ikoria // Zilortha, Apex of Ikoria 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

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.) When this Siege enters, search your library and/or graveyard for a non-Human creature card with mana value X or less and put it onto the battlefield. If you search your library this way, shuffle. Reach For each non-Human creature you control, you may have that creature assign its combat damage as though it weren't blocked.

Complete guide

Invasion of Ikoria brings the primal power of a monster-filled plane to your tabletop, serving as both a powerful tutor and a game-ending threat. This Siege battle allows you to recruit a non-Human ally from the depths of your library or graveyard to immediately join the fray. Once defeated, it transforms into Zilortha, Apex of Ikoria, a legendary Dinosaur that makes your non-Human army virtually unblockable.

Searching for Survivors

When Invasion of Ikoria enters the battlefield, you choose a value for X. You then search your library and/or your graveyard for a non-Human creature card with mana value X or less. This versatility is key: if your best threat is already in the graveyard, you can bring it back; otherwise, you can dig through your library. If you choose to search your library, you must shuffle it afterward. The creature is put directly onto the battlefield, bypassing the stack and conventional counterspells targeting creature spells.

Sieging the Battle

As a Siege, you must choose an opponent to protect it. You and other players can attack the battle or target it with 'any target' damage spells to remove defense counters. When the last defense counter is removed, the Siege's intrinsic triggered ability fires: you exile the card and cast its back face, Zilortha, Apex of Ikoria, transformed without paying its mana cost.

Zilortha's Combat Dominance

Zilortha provides a powerful static ability for your non-Human creatures. For each such creature, you decide just before damage is assigned whether it ignores blockers. If you choose to use this effect, the creature deals its full combat damage directly to the player, planeswalker, or battle it is attacking. Note that this is all-or-nothing; you cannot split damage between a blocker and the defending player. Furthermore, even if your creature ignores blockers to deal damage, the blocking creatures will still deal damage back to your creature as normal.

Common Pitfalls

The most important restriction on Invasion of Ikoria is the 'non-Human' clause. You cannot find a Human creature with the entry trigger, and Zilortha's damage-assignment ability does not apply to Humans. Additionally, if you use a card to copy Invasion of Ikoria that isn't a transforming double-faced card, you won't be able to cast the back face when the battle is defeated—the copy will simply stay in exile.

Interaction examples

Ramping into the Invasion

Llanowar Elves

On turn one, you play Llanowar Elves. On turn two, you tap a Forest and your Elves to produce three mana, casting Invasion of Ikoria where X=1. When it enters, you search your library for another Llanowar Elves (a non-Human Elf) and put it onto the battlefield. This effectively uses the battle as a way to build your mana base while putting a permanent on the board to be flipped later.

Bypassing the Skies

Birds of Paradise

You have Zilortha, Apex of Ikoria on the battlefield and attack your opponent with Birds of Paradise. Your opponent blocks with a large flying creature. Before damage assignment, you choose to have Birds of Paradise assign its damage as though it weren't blocked. Because Birds of Paradise has 0 power, it deals no damage to the player, but it still receives lethal damage from the blocker and dies. If you had increased the Birds' power with a spell, it would have dealt that damage directly to the opponent despite being blocked.

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

How it works : Invasion of Ikoria // Zilortha, Apex of Ikoria

Original English text — Wizards of the Coast / Scryfall

#1April 14, 2023· Wizards of the Coast
You decide whether to assign a non-Human creature’s combat damage as though it weren’t blocked just before it assigns that damage. You may make a different choice for each non-Human creature you control—that is, you may have none, some, or all of those creatures assign combat damage as though they weren’t blocked.
No other card is named in this ruling.
#2April 14, 2023· Wizards of the Coast
Assigning a creature’s damage as though it weren’t blocked is all or nothing. You can’t use this effect to assign some of the creature’s damage to a blocking creature and the rest to the player, planeswalker, or battle it’s attacking.
No other card is named in this ruling.
#3April 14, 2023· Wizards of the Coast
Even if a creature assigns damage as though it were not blocked, it will still receive damage from creatures that are blocking it.
No other card is named in this ruling.
#4April 14, 2023· Wizards of the Coast
Sieges each have an intrinsic triggered ability. That ability is “When the last defense counter is removed from this permanent, exile it, then you may cast it transformed without paying its mana cost.”
No other card is named in this ruling.
#5April 14, 2023· Wizards of the Coast
As a Siege enters the battlefield, its controller chooses an opponent to be its protector.
No other card is named in this ruling.
#6April 14, 2023· Wizards of the Coast
A Siege’s controller can’t be its protector. If a Siege’s protector ever gains control of it, they choose a new player to be its protector. This is a state-based action.
No other card is named in this ruling.
#7April 14, 2023· Wizards of the Coast
If a non-battle permanent that is already on the battlefield become a copy of a Siege, its controller chooses one of their opponents to be that battle’s protector. However, it will most likely be put into its owner’s graveyard because it has no defense counters (see below).
No other card is named in this ruling.
#8April 14, 2023· Wizards of the Coast
A battle’s “defense” is displayed in the bottom right corner of the card. A battle enters the battlefield with that number of defense counters. If another permanent enters the battlefield as a copy of a battle, it also enters with that number of defense counters.
No other card is named in this ruling.
#9April 14, 2023· Wizards of the Coast
Only creatures controlled by a battle’s protector can block creatures that are attacking that battle. This means a Siege’s controller can never assign creatures to block for it.
No other card is named in this ruling.
#10April 14, 2023· Wizards of the Coast
A battle can be dealt damage and be target of spells and/or abilities that target “any target.”
No other card is named in this ruling.
#11April 14, 2023· Wizards of the Coast
Damage dealt to a battle causes that many defense counters to be removed from it.
No other card is named in this ruling.
#12April 14, 2023· Wizards of the Coast
A battle can be attacked by all players other than its protector. Notably, this means a Siege’s controller can attack it.
No other card is named in this ruling.
#13April 14, 2023· Wizards of the Coast
If a battle has no defense counters, and it isn’t the source of a triggered ability that has triggered but not yet left the stack, that battle is put into its owner’s graveyard. This is a state-based action. This doesn’t cause a Siege’s intrinsic triggered ability to trigger.
No other card is named in this ruling.
#14April 14, 2023· Wizards of the Coast
If a Siege never had defense counters on it (perhaps because a permanent became a copy of one), it can’t have its last defense counter removed. It will be put into its owner’s graveyard. You won’t exile it or cast the other face.
No other card is named in this ruling.
#15April 14, 2023· Wizards of the Coast
If a token or a card that isn’t represented by a transforming double-faced card becomes a copy of a Siege, it can’t be cast as its triggered ability resolves. It will remain in exile. If it’s a token, it will cease to exist the next time state-based actions are performed.
No other card is named in this ruling.
#16April 14, 2023· Wizards of the Coast
If a permanent that is represented by a transforming double-faced card becomes a copy of a Siege, it will be exiled as that Siege’s triggered ability resolves, then it will be cast transformed. Note that this applies only to transforming double-faced cards, not to modal double-faced cards that can normally be played using either face.
No other card is named in this ruling.
#17April 14, 2023· Wizards of the Coast
In a multiplayer game, if the protector of a battle leaves the game and that battle is not currently being attacked, its controller chooses a new protector for it as a state-based action. If it is being attacked, its controller chooses a new protector for it once no creatures are attacking it. This means that it continues to be attacked and can be dealt combat damage as normal.
No other card is named in this ruling.
#18April 14, 2023· Wizards of the Coast
If a battle that’s being attacked somehow stops being a battle, it is removed from combat. Similarly, if its controller changes in the middle of combat, it is removed from combat.
No other card is named in this ruling.
#19April 14, 2023· Wizards of the Coast
Battles can’t attack or block, even if one also becomes a creature. If an attacking or blocking creature somehow becomes a battle in addition to being a creature, it is removed from combat.
No other card is named in this ruling.