Damage

Damage is classed into two basic forms:

Battle Damage

and

Effect Damage

Life Point Costs for Card is not considered damage, so cards like Wall of Revealing Light, Dimension Fusion, Final Countdown, Brain Control, and Premature Burial cannot have their Costs re-directed via Barrel Behind the Door.

Self-Destruct Button does not inflict damage, and just simply changes Life Points to 0.