In the event of a falling out with a supervisor (Master's thesis or PhD) is there generally anything one can do about it if one wants to apply to a (different) PhD program, for which one would need a recommendation letter? I am mostly interested in the European academia. 

I am certain this must have happened a lot in the history of academia and I am wondering what happens in such situations. Is it the end of one's academic career? Are the other options to leaving or (if possible) changing research groups within the university? I know that one can't force a person to write a positive letter, but is there anything that outsiders can do to effect such a situation or is all the power with the supervisor?