Sanctuary consists of 21 individual 1x1 area of effects (AoEs) with a splash radius of 1. Each sub-AoE continuously scans for entities and may decrement the wave counter when an entity is found. Sanctuary is dispelled when the wave counter reaches zero.

If the entity is not demon or decay, and is not full HP; the sub-AoE heals the entity, applies a brief immunity, and decrements the wave counter by 1. If the aforementioned entity is full HP or is a decay ally; the sub-AoE does nothing. If the entity is a demon or decay enemy; the sub-AoE inflicts knockback and holy magic damage equal to half the heal amount, applies a brief immunity, and decrements the wave counter by 2 instead. Each sub-AoE has directional knockback away from the center, whereas the centerpoint knockback is westbound.

These sub-AoEs are processed from west to east then south to north. This order influences the knockback direction where the sub-AoEs overlap with a preference to the northeast. Similarly, a prior instance of Sanctuary overrides a subsequent cast over the same area until it expires.

Sanctuary effectiveness may be increased by recovery bonuses.

heal = heal * (1 + recovery_bonus / 100)