In 5e, the Blinded condition is described in the PHB p.290 as:
A blinded creature can't see and automatically fails any ability check that requires sight. Attack rolls against the creature have advantage. and the creature's attack rolls have disadvantage
Grappling in the PHB calls grappling a “special Melee attack.” PHB p.195:
...you can use the Attack action to make a special melee attack, a grapple....
But grappling is also described as an ability check.
...Using at least one free hand, you try to seize the target by making a grapple check, a Strength (Athletics) (Athletics) or check contested by the target's Strength Dexterity (Acrobatics) check...
Given these details, if a character were to attempt to Grapple a Blinded creature, which then is true?
- The character grappling the Blinded creature gets Advantage against the Blinded condition
- Grappling is not technically an attack but rather an Ability check and thus doesn’t get Advantage
- Grappling is both (a Melee attack subject to Attack modifiers and an Ability check subject to Ability modifiers)?