Have you ever met someone who made you reconsider something you swore you’d never do?
Has something ever happened that changed your mind about something?
Has there ever been a series of events that change the outcome of something?
Those events can be called game changers.
Use the noun game changer to describe something that happens and completely changes something else.
It affects the outcome of something. It changes something dramatically.
For example:
I never wanted to get married but she was a game changer.
This dress is a game changer.
Getting my scholarship was a game changer.
Have you ever had a game changer in your life?