A unit 'interacts' with the realm if it does any of the following things: Strikes Casts a spell Activates a special ability Note that only activated abilities can be activated. Triggered abilities and passive abilities aren't activated. Note that a 'special ability' is different from a 'basic ability'. Deal damage (even if the damage is prevented) Note that 'deal damage' is mostly but not fully covered by the first three bullet points. 'Activates a special ability' doesn't include triggered abilities, since only activated abilities can be activated. There are some triggered abilities that could deal damage, e.g. Infernal Legion or Colicky Dragonettes, which are intentionally included in 'interacting.'