I wanted to ask what to do if my opponent does exd5 in french defense
Simply exd5.
Black responds with exd5 then what should black do after that ?
Just develop normally after exd5 from white you are safer than a vault...Nf6, Bc5/Bb4/Be7, 0-0, c6, Nbd7(you may bring the light-squared bishop before), etc...
That is the one time in the tournament I have faced that opening white was way too passive !!
I wanted to ask what to do if my opponent does exd5 in french defense