Sanctum CustodianHow it works & interactions with other cards

How Protection Works

The ability of Sanctum Custodian creates a prevention shield that lasts until the end of the current turn or until it prevents damage. You choose a target upon activation, which can be a player, a planeswalker, or any creature. The next 2 damage that would be dealt to that target is simply ignored, meaning it is never dealt at all. If the source would deal only 1 damage, the remaining 1 point of prevention continues to wait for the next instance of damage within the same turn.

Step-by-Step Resolution

First, you activate the ability by tapping Sanctum Custodian; this puts the ability on the stack and requires you to choose a target. Second, players have a chance to respond with spells or abilities. Third, once the ability resolves, it creates a continuous effect that watches for damage. The next time the target would be dealt damage this turn, up to 2 of that damage is prevented. If no damage is dealt to that target before the turn ends, the shield simply expires.

Common Mistakes

One common error is trying to prevent damage that has already been dealt; you must activate the Custodian before the damage step of combat or before a damage-dealing spell resolves. Another mistake is assuming it stops 'loss of life' effects. Prevention only works against damage; if an effect says a player loses life, Sanctum Custodian cannot stop it. Finally, remember that if a source deals damage that 'cannot be prevented,' the Custodian's shield will fail to function.

Strategic Timing

Sanctum Custodian is best used to change the outcome of combat trades. By targeting one of your blocking creatures, you can allow it to survive a clash that would otherwise be lethal. It is also excellent for countering small 'ping' effects from spells or abilities, forcing your opponent to commit more resources than they planned to remove your threats.

Interaction examples

Protecting the Robot

Solemn Simulacrum

If your opponent casts a spell to deal 2 damage to your Solemn Simulacrum, you can respond by tapping Sanctum Custodian to target the Golem. The ability resolves first, creating a shield. When the damage spell resolves, the 2 damage is prevented, and Solemn Simulacrum stays on the battlefield to provide its value later.

Strategic Tribal Defense

Roaming Throne

If you have Roaming Throne on the battlefield and chose 'Human' or 'Cleric', the Throne's ability only doubles triggered abilities. Since Sanctum Custodian has an activated ability (indicated by the colon), the Throne does not double it. However, if Roaming Throne is targeted by a damage source, Sanctum Custodian can still prevent 2 of that damage to keep your Golem safe.

Survival in Combat

When Sanctum Custodian blocks a creature with 2 power, you can tap it to target itself before damage is dealt. During the combat damage step, the 2 damage from the attacker is prevented. Because the damage was prevented, your Custodian survives the combat, though it will remain tapped during your next turn unless untap effects are used.