Shuushin15 Nov 2003

I think what he means that there are more definitions, let me help with *actually providing information*:

Meaning "double walker" a doppelganger is a shadow-self that accompanies every human. Only the owner of a doppelganger can see it, otherwise it is invisible to human eyes. Dogs and cats have been known to see doppelgangers. Providing sympathetic company, a doppelganger almost always stands behind a person, and they cast no reflection in a mirror. They are prepared to listen and give advice to humans, either implanting ideas in their heads, or a sort of osmosis. It is said to be bad luck if it is seen, and rarely a doppelganger will make itself visible to friends or family, often causing great confusion. Doppelgangers can be mischievous and malicious.

or

the literal german translation is "double goer"

or

As used in various role playing games - like DUNGEONS and DRAGONS (tm) - is that better, dik?