When voice acting is out of scope

When voice acting is out of scope because of budget or another reason.
In what way would present dialogs between characters without breaking the imersion?

I understand that with RPG/ROL games simple dialogs animations and text could work just fine, but when you are working with something that should feel real enough,
is posible skip voice acting at all?
there are some tecniques?
Do you have some experiencie with this?
Opinions?

Thanks :smiley:

Alex.-