Replacement effects replace one event with another. These types of effects often use the word 'instead' and 'would,' with phrases like 'would die,' 'would take damage,' 'would successfully attack,' or 'would untap.' For example, Gilded Aegis is a replacement effect for a minion dying. It's constantly looking for the moment that minion is about to die, then it replaces that event (the minion dying) with a different event (healing the minion and banishing the Gilded Aegis). In such a situation, the minion never actually died, and the game was actually looking ahead just slightly to see it, then trigger and resolve the replacement effect. Note that replacement effects do not use the storyline; they immediately resolve as soon as they are triggered. See the 'Damage' codex entry and subsections for more details on damage-specific replacement effects.