Albert Barnes Commentary Judges 9:52

"And Abimelech came unto the tower, and fought against it, and drew near unto the door of the tower to burn it with fire." — Judges 9:52 (ASV)

Went hard to the door ... - i.e., went close to the door. An act of manifest danger, since the roof was covered with people who would likely throw down all sorts of missiles on the heads of their assailants. But the hatred of Abimelech, and his thirst for revenge, made him despise danger.