­What is heresy? Heresy is a keyword action features on creatures. Each card that can commit heresy may commit heresy in a different way; however, any instance of heresy will trigger all heresy conditions. Heresy in and of itself does nothing, and it is the creatures' other abilities that trigger from heresy being committed. Some creatures may commit heresy as an activated ability (e.g. Ruthless Instructor, other creatures set up conditions that in which the player's actions can trigger heresy (e.g. Proactive Dream-Thief.

Heresy cards where heresy triggers from activated abilities: ­
Ruthless Instructor, Corrupt Councilor,Mad Heretic, Hypocritical Citizen

Heresy cards where heresy is triggered on a condition: ­
False Immolator Priest, Cannibal of the Cult, Crematory Profiteer, Data-Deprived Wołchw, Storm-Chaser Scholar, Proactive Dream-Thief, Tormentor of Souls, Wazykt Missionary

Cards that do not have a heresy condition, but interact with heresy:
­Nature's Unpredictability