At 7th level, rogues gain the Evasion feature:
Beginning at 7th level, you can nimbly dodge out of the way of certain area effects, such as an ancient red dragon’s fiery breath or an ice storm 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.
The Immolation spell certainly allows a Dexterity save for half damage, but it is not an “area effect”:
Flames wreathe one creature you can see within range. The target must make a Dexterity saving throw. It takes 8d6 fire damage on a failed save, or half as much damage on a successful one. […]
Given that Evasion mentions dodging “certain area effects”, does that prevent it from working spells that do not target an area, such as immolation? Or does evasion apply to all Dexterity saves for half damage?
(Other example spells include enervation and flaming sphere.)