Rule 355.10.c

It is included only as part of a cost, trigger condition, or replacement effect. e.g., “As an additional cost to play me, kill a friendly unit” doesn’t target anything. e.g., “When a friendly unit dies, kill a gear” targets a gear, but not a friendly unit. e.g., “When you play me, the next time a friendly unit would die this turn, return it to your hand instead” doesn’t target anything. The replacement effect applies when any friendly unit dies. e.g., “Choose a friendly unit. The next time it would die this turn, return it to your hand instead” targets a friendly unit, because “choose a friendly unit” is not part of the replacement effect.