Evasion is a Monk feature gained at level 7 in D&D 5e. At 7th level, your instinctive agility lets you dodge out of the way of certain area effects, such as a blue dragon's lightning breath or a fireball spell.
At 7th level, your instinctive agility lets you dodge out of the way of certain area effects, such as a blue dragon's lightning breath or a fireball spell. When you are subjected to an effect that allows you to make a Dexterity saving throw to take only half damage, you instead take no damage if you succeed on the saving throw, and only half damage if you fail.