What is considered a good GPA for studies in Germany
Given that "grade inflation" is often much less rampant in Germany than in other nations (it is not unusual, for instance, for the majority of students to fail an exam in a core subject), the standards inside of Germany tend not to be as stringent as in other places I've seen. For instance, anything better than 2.0 (on a 5.0 scale, not a 4.0 scale!) would generally be considered "competitive."

Obviously, there are limitations—if you get a 2.0 because you've gotten 1.0's in the general courses and 3.0 in the courses in your subdiscipline, you're not likely going to be an attractive candidate to an outside group.

However, I think much more important than the exact GPA is the quality of the master's thesis. If you have a very strong master's thesis, you will likely get some interest from the group in which you did the thesis work to continue on for a PhD, if there is an open position available. A weak grade on the thesis (anything below a 1.3) usually is a sign of substandard performance, which is likely to result in not being considered for a position, even if your GPA is a 1.1 or 1.2 (it's unlikely to be a 1.0 under such circumstances).