Berlin has an excellent public transportation system, the BVG (Berliner Verkehrsgesellschaft). The tube (U-Bahn) goes well beyond the city limits, and numerous lines intersect to maximise coverage. This is augmented by the light rail (S-Bahn), tram, and bus systems. At night, a network of night busses, running on average every 15 minutes, allows for easy movement throughout the city.

Unlike many public transportation systems, the BVG does not make use of turnstiles or other obstacles to ensure that passengers pay their way. Basically, the BVG works on an honour system. There are vending machines at every station from which to purchase tickets ranging from the short-distance ticket (Kurzstrecke) to the Umweltskarte, which allows for use of all public transportation for a calendar month, but there is nothing stopping anyone from entering without buying a ticket.

Most of the time.

The BVG does make use of a small army of uniformed ticket checkers (Fahrscheinkontrolleure), who randomly board trains and busses to check passengers/ tickets and to obligate those without tickets to pay a surcharge in the amount of EUR 40.00. It used to be that these ticket checkers could go undercover without any form of identifying clothing. Now, however, the Kontrolleure wear rather tacky blue-and-green uniforms. They show up only rarely, if you're lucky.

For those who want to get a free ride (known in Germany as Schwarzfahren), there are a few simple guidelines to follow:

1. Don't get too comfortable. Since there is no way to predict where and when someone will ask for your ticket, you have to stay alert. Stand as close to a rear exit door as possible. This will generally give you the best angle of sight to see if there's a blue-green swarm on the platform.

2. Take short stretches. The longer you stay on the same train, the more likely it is that you will get caught. Getting off every couple of stations is a good rule of thumb.

3. Stay calm. Avoid drawing attention to yourself.

4. If disaster strikes: If you see a lot of tacky blue and green suits running around the platform, get out. Do so quickly and calmly. The goal is to find a mobile crowd and blend into it. Just because you're out of the train car itself doesn't mean you're home free.

5. If you get caught: They'll ask for your identification and give you a piece of paper that requires you to pay EUR 40. This is rarely enforced, and if you ignore it, you usually will not have to worry about any serious consequences until you've done it a few times. Sometimes, you'll have criminal charges filed against you (§ 265a - Erschleichen von Leistungen / Unlawfully obtaining services). The Staatsanwaltschaft in Berlin has plenty of actual felonies to deal with, and will often dismiss the charges "for want of public interest in prosecution."