Use when describing an uneven result after a confrontation or challenge. After the debate, the less experienced speaker clearly came off worse.
Pro Tip 2/3
Not Literal
It's often used metaphorically, not just for physical fights but any competitive situation. In the trade negotiations, the smaller country came off worse.
Pro Tip 3/3
Subjective Perspective
It may reflect a personal opinion on who fared worse, and others might disagree. Many feel that, in the split, Laura came off worse, losing mutual friends.