German for "doublewalker", a doppleganger is a myth
ological creature or concept. As legend
has it, everyone has a doppleganger, which is forged from the real counterpart's own will
. No one can see it unless it chooses to appear. It will manifest itself before its real counterpart first, and announce its intentions. The ideal time for a doppleganger to appear is during the new moon
, when the real counterpart does not cast a shadow
Provided the real counterpart is inherently good, the doppleganger will attempt to provide helpful assistance to the real counterpart. Dopplegangers can be mischievous however, and rarely ever get good deeds right. Benevolent dopplegangers can impart advice to their counterpart, or they can subtly affect their counterpart's actions and thoughts. In fact, theoretically when one chooses to listen to one's conscience, they may be dealing with their doppleganger, unrealized and trapped within the shadow. If the deep center of the real counterpart's soul is malevolent in any way, the worst qualities of the real counterpart will be used to create the doppleganger. The results can be disastrous.
Malevolent dopplegangers will attempt to take over the real counterpart's life by appearing before their loved ones and acquaintances. The doppleganger replaces the real counterpart's daily activities, where the real counterpart has been negligent. If the real counterpart is a workaholic, the doppleganger will spend more time with friends and family, until the real counterpart finds himself literally written out of his or her own life and left a shadow of his/her former self. A real counterpart is forever a threat to the doppelganger's success, but ancient legend says if one dies so does the other, for they are forever linked at the point where the shadow is cast. If the doppleganger is successful in replacing his/her counterpart for a full cycle of the moon, their roles are reversed forever.
A malevolent doppleganger, during the process of taking over his/her real counterpart's life, can be spotted by an outsider in many ways. Dopplegangers are unable to cast a shadow. Dopplegangers cannot cast a reflection in a mirror. There is also usually some minor flaw in the doppleganger's appearance or mannerisms, but only those closest to the real counterpart will be able to tell the difference in this way, and the doppleganger being aware of this comparative deformity, will deftly try to hide it.
The doppleganger's greatest power against its real counterpart is knowledge. Dopplegangers theoretically have been with the counterpart their entire lives. They know everything about their adversary, which makes them difficult to outsmart. They will also use the counterpart's own regrets, anxieties and self-loathing against them. However, this can be used against a doppleganger, provided the real counterpart is willing to face his true self and use both the bad and good aspects of his personality, then change his behavior and routine in order to upset his rival. This is worse than a cat & mouse game. It is a fight for survival against an exact equal. One has to learn to be two steps ahead of oneself in order to defeat the doppleganger before the next new moon.
Or so the legend goes.
Over the centuries this legend has been manipulated and re-examined to tell no end of stories. On a literal level, the famous tale Doctor Jeckyl and Mister Hyde is a gothic example of the Doppleganger conundrum, in which the counterpart pulled his shadow self out by way of chemical science. On a more metaphorical level, the term "doppleganger" can also apply to other worthy adversaries in fiction and history. The Headless Horseman to Ichabod Crane. Moriarty to Sherlock Holmes. Ra's Al Ghul to Batman. Khan Noonien Singh to James Tiberius Kirk. The list goes on.
But be this legend or fiction, we each have an alter-ego inside us ready to come out. We can opt to share all facets of ourselves with our lives, or push those parts of ourselves which we fear or hate into the deepest recesses of our own will. In so doing, one may inadvertently be creating the very psycholgical abberation which could make this myth a reality.