Effect
Prone
A Prone creature cannot move or act until it gets up.
Attacks made from within 3 m have Advantage. Prone does not by itself make every hit a critical hit.
Standing costs half its movement speed. Falling Prone immediately breaks Concentration, making it useful against concentrating enemies. Falling on its own turn also ends that turn.
The Prone creature also has Disadvantage on Strength and Dexterity saving throws.