Questiomn about contract

I still gather all the informations about website design business.
And this forum helps me to do that .

I know that when working with client I should have a contract signed by
the client and me .
My question is :
If I have contract , well considered with lawyer , from every point , signed
with my client and I have abided it - should I be afraid of being sued by the
client ?
How possible is thath client will win and I will have to pay him moneny ?

Thanks in advance , Bartek