Agent of the Shadow Thieves — ruling 1

The ability granted by Agent of the Shadow Thieves is looking to see if any of the attacking player's opponents have a higher life total than that defending player. The attacking player's life total is not included in this comparison.

Agent of the Shadow Thieves — ruling 2

Choose a Background is a variant of the partner ability. You may have two commanders if one of them is a legendary creature with the choose a background ability and the other is a legendary Background enchantment. Backgrounds and cards with choose a Background do not interact with cards which have any other partner ability.

Agent of the Shadow Thieves — ruling 3

If your Commander deck has two commanders, you can include only cards whose own color identities are also found in your commanders’ combined color identities.

Agent of the Shadow Thieves — ruling 4

Both commanders start in the command zone, and the remaining 98 cards (or 58 cards in a Commander Draft game) of your deck are shuffled to become your library.

Agent of the Shadow Thieves — ruling 5

If your commander loses the choose a Background ability or stops being a Background during the game, as appropriate, it is still your commander.

Agent of the Shadow Thieves — ruling 6

Once the game begins, your two commanders are tracked separately. If you cast one, you won’t have to pay an additional {2} the first time you cast the other. A player loses the game after having been dealt 21 combat damage from any one of them, not from both of them combined (although your Background won’t usually be a creature anyway).

Agent of the Shadow Thieves — ruling 7

If something refers to your commander while you have two commanders, it refers to one of them of your choice. If you are instructed to perform an action on your commander (e.g. put it from the command zone into your hand due to Command Beacon), you choose one of your commanders at the time the effect happens.

Agent of the Shadow Thieves — ruling 8

An effect that checks whether you control your commander is satisfied if you control one or both of your two commanders.

Agent of the Shadow Thieves : règles, fonctionnement et interactions (MTG)

Agent of the Shadow Thieves 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

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, put a +1/+1 counter on this creature. It gains deathtouch and indestructible until end of turn."

Complete guide

Agent of the Shadow Thieves is a powerful Background enchantment that turns your Commander into a lethal, resilient threat. By rewarding you for targeting the most healthy player at the table, it encourages aggressive play while protecting your leader. This card is perfect for decks that want to maintain pressure without risking their Commander in combat.

Empowering the Commander

This Background grants an triggered ability to any Commander creature you own. The ability triggers specifically when that Commander attacks a player. When the trigger resolves, it checks a condition: is the player being attacked the one with the highest life total among your opponents (or tied for it)? If so, your Commander grows permanently and becomes nearly impossible to kill for the duration of the turn.

Resolution Step-by-Step

First, declare your Commander creature as an attacker against an opponent. If the conditions are met, the ability goes on the stack. Upon resolution, the game compares the life total of the player you are attacking against all of your other opponents. Note that your own life total is ignored for this check. If no other opponent has a higher life total than the defending player, your Commander receives a +1/+1 counter and gains both deathtouch and indestructible until the end of the turn.

Common Pitfalls

A common mistake is forgetting that the check happens upon resolution of the trigger, not just when the attack is declared. Additionally, this effect only applies if you attack a player; it does not trigger if your Commander attacks a planeswalker or a battle. Lastly, if you have two Commanders (via the 'Choose a Background' mechanic), this enchantment grants the ability to both of them, provided they are currently creatures on the battlefield.

Strategic Timing

Since the ability relies on your opponent having the most life, cards that drain your own life total can be surprisingly helpful to keep the opponents' totals relatively higher than yours, though your own health doesn't technically impact the trigger's math. It is best played in decks where your Commander has evasion or high power, ensuring the deathtouch and indestructible keywords make blocking a nightmare for your enemies.

Interaction examples

Managing Life Totals

Phyrexian Arena

With Phyrexian Arena in play, you draw extra cards but lose 1 life each turn. While this lowers your health, Agent of the Shadow Thieves only cares about the life totals of your opponents. As long as the opponent you are attacking isn't trailing behind your other opponents in life, your Commander will continue to gain counters and protections regardless of how low your own life drops from the Arena.

The Cost of Power

Black Market Connections

Black Market Connections allows you to exchange life for resources like Treasure or creatures. If you use this to stay aggressive, you can ensure you have the mana to cast your Commander early. Once your Commander attacks, Agent of the Shadow Thieves checks if the defending player is the 'life leader' among your foes. Even if you have used Black Market Connections to drop your own life to 10, the ability still triggers as long as the player you attack has at least as much life as your other opponents.

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

How it works : Agent of the Shadow Thieves

Original English text — Wizards of the Coast / Scryfall

#1June 10, 2022· Wizards of the Coast
The ability granted by Agent of the Shadow Thieves is looking to see if any of the attacking player's opponents have a higher life total than that defending player. The attacking player's life total is not included in this comparison.
No other card is named in this ruling.
#2June 10, 2022· Wizards of the Coast
Choose a Background is a variant of the partner ability. You may have two commanders if one of them is a legendary creature with the choose a background ability and the other is a legendary Background enchantment. Backgrounds and cards with choose a Background do not interact with cards which have any other partner ability.
No other card is named in this ruling.
#3June 10, 2022· Wizards of the Coast
If your Commander deck has two commanders, you can include only cards whose own color identities are also found in your commanders’ combined color identities.
No other card is named in this ruling.
#4June 10, 2022· Wizards of the Coast
Both commanders start in the command zone, and the remaining 98 cards (or 58 cards in a Commander Draft game) of your deck are shuffled to become your library.
No other card is named in this ruling.
#5June 10, 2022· Wizards of the Coast
If your commander loses the choose a Background ability or stops being a Background during the game, as appropriate, it is still your commander.
No other card is named in this ruling.
#6June 10, 2022· Wizards of the Coast
Once the game begins, your two commanders are tracked separately. If you cast one, you won’t have to pay an additional the first time you cast the other. A player loses the game after having been dealt 21 combat damage from any one of them, not from both of them combined (although your Background won’t usually be a creature anyway).
No other card is named in this ruling.
#7June 10, 2022· Wizards of the Coast
If something refers to your commander while you have two commanders, it refers to one of them of your choice. If you are instructed to perform an action on your commander (e.g. put it from the command zone into your hand due to Command Beacon), you choose one of your commanders at the time the effect happens.
No other card is named in this ruling.
#8June 10, 2022· Wizards of the Coast
An effect that checks whether you control your commander is satisfied if you control one or both of your two commanders.
No other card is named in this ruling.
#9June 10, 2022· Wizards of the Coast
You can choose two commanders that are the same color or colors.
No other card is named in this ruling.
#10June 10, 2022· Wizards of the Coast
If a card refers to a commander creature you own, a Background won't usually be counted or included for that effect. If another spell or ability causes your Background to become a creature, however, it will be included. Any effect that refers to your commander or a commander you own or control without specifying creature will apply to a Background that is your commander, as appropriate.
No other card is named in this ruling.
#11June 10, 2022· Wizards of the Coast
If you control a Background that grants an ability to commander creatures you own, and you own more than one commander creature, each of them will have that ability.
No other card is named in this ruling.