Breach X

How Breach works

Breach rewards winning battles. When this Unit's attack destroys an enemy Unit, it immediately deals the listed damage to the first (topmost) card in that opponent's shield area. One attack gets you a board trade and shield pressure at the same time, which is what aggressive decks are after.

The trigger is specifically your attack destroying an enemy Unit. Attacking shields directly doesn't trigger Breach; there was no Unit destroyed.

Rulings & edge cases

Breach damage is effect damage, not battle damage, and the official FAQs are explicit about it. This helps you and hurts you. Protection effects that only stop battle damage (or damage from Units of a certain level) won't stop Breach, and a Base sitting in the shield area can be hit by Breach damage even when other effects shield it from Unit attacks.

Conditionally granted keywords are checked live. In one official ruling, a Unit whose AP was raised to meet a 'gains <Breach>' condition lost the keyword again when an opponent's Command lowered its AP mid-turn. If the condition lapses before the attack resolves, the Breach never happens.

Playing with and against it

Breach punishes chump-blocking, because every small Unit thrown in front of a Breach attacker turns into shield damage anyway. Block with Units that survive the battle, or remove Breach attackers before combat. Once you have lost the battle, the shield damage is already locked in.