Attack immunity
Attack immunity is the name given to the effect present on a number of cards that makes you completely unaffected by your opponent's attacks. While there exist other ways of mitigating the impacts of certain attacks, such as trashing incoming junk using Watchtower, cards providing attack immunity completely nullify all forms of attack.
Attack immunity only works against attack cards if it is in force when the attack is played. In the case of duration attacks such as Swamp Hag, if your opponent plays their attack before you put attack immunity into effect, you will still suffer the effects of the attack.
Noble Brigand also performs its attack when it is bought. Attack immunity does not block the attack in this case, as buying Noble Brigand is not playing it. Haunted Castle and Ill-Gotten Gains have on-gain effects that similarly cannot be blocked.
Some cards can have effects that can feel like attacks but are not. Examples include Masquerade and Possession. Only cards with the Attack type can be blocked.
Attack immunity does not prevent you from using reaction cards that trigger when an opponent plays an attack card, such as Diplomat or Horse Traders. That is because these cards are not conditional on you being affected by the attack, merely that an attack card was played.
List of cards
Gallery