Not that it's one of the top 500 things to know in Germany....but you might be curious.
A level of .05 is enough, to get you a DWI in Germany. Your license generally gets taken on the spot, and you get carted off to the jail to be bailed out. Within a couple of weeks, you will end up at a court appearance, and there's this summary read aloud. The cops will be smart enough to take a blood test (which you must submit to) at the scene. The results will be absolute.
At this point, the judge will give you a choice of a fine or days in jail. Most Germans will select the fine. Unless you are mostly broke....that's about the only reason not to pick the fine.
Then the judge discusses the period of your license being lost. It's always six months. You can argue all you want....but it doesn't matter. If you need a ride to work....you either get your relatives to drive you, or you start walking or riding public transportation.
The fine? Well.....usually a couple thousand Euro.
The second DWI? Life gets to be a bit miserable at this point. Usually, it's a two-year loss, and the fine goes into a pretty hefty range (over ten thousand).
Hiring a lawyer to fight the DWI? If they took the blood test, it's a iron-clad case....you simply are burning up your cash in hiring a lawyer.
What is the potential for the cops stopping you? Well, this gets to be interesting. During most daylight hours....it's like a one-percent chance of the cops having a random checkpoint. Friday and Saturday evenings? The numbers go up to a thirty-to-forty percent chance of a random checkpoint. They will set up various points within the heart of a city, or along the major roads leading out of a town.
My advice is simple....if you want to really want to consume more than one beer or wine in Germany....you ought to select some pub in your neighborhood, and just walk over. Spend four hours there, and drink five or six beers.....and just stumble your way home. If you drive out and are the driver for the evening....your honest limit is maybe one beer, and flip over to sodas, tea, or fizzy water. These guys don't kid around about DWI situations.