Yesterday, I talked about mirror characters and why they’re useful. Today, I’m going to talk about the most important aspect of a mirror character: its similarities to the base character.

After all, the important thing about a mirror character, particularly one that is supposed to demonstrate to the base character either the inevitability or preferability of the mirror’s path or state, is that the base character recognizes, not just herself, but herself as she sees herself before modification. The essential base-ness of the character cannot be in question, or the mirror looks more like a bad joke and doesn’t hold the same sort of temptation or disgust; in sum, the base character needs to recognize herself in a mirror.

As a result, not only is the mirror going to need to have at least three things in common with the base character (not counting appearance, as that one’s optional), those three things are going to need to as close to character-defining traits as you can get. Cunning, dedication and a history involving being ostracized by half a village might count; love of the color blue, an interest in underwater basket-weaving, and a shared favorite poem just looks like not trying hard enough. While someone who is visually the same but seems to have embodied all of the traits that a character has left behind is technically still a mirror, she’s not going to have the same kind of power as one who is the character but for a little less human empathy and a different Cause to focus on.

But just because a mirror is similar doesn’t mean she has to be practically identical; if the separation in circumstances is sufficient, mirror characters can be vastly different from each other and still ring true. Again, the important part is just getting the qualities that actively define the character rather than just being things that spring from who the character is. Some interesting sources of distortion might be growing up in a different culture (or under a different timeline, or what have you), just about anything that comes from having taken a different path at the same decision point,

This, also, is why the magnification of existing character traits is such a popular way of differentiating mirror characters from their bases. It makes it easier to make the mirroring obvious: the characteristics simultaneously count as similarities and differences, making it easier to both demonstrate the mirror’s connection to the base character and her qualities as a warped reflection.

And speaking of appearance, in many cases, particularly when the mirroring is being played for its thematic beauty, appearance is a common element to the mirror/base relationship. For a lot of people, this is taking the same set of features and adding minor cosmetic differences: a palette swap here, a reversed or changed symbol there, an exaggeration of the physical features, a change in the style of outfit (though I do get sick of the evil opposite always being dressed sexier; don’t get me started on the implications, we’ll be here all night), any of a number of things.

In short, remember similarities. After all, even a funhouse mirror, with all its distortions, still needs to reflect something that is recognizably its source; so too must a mirror character be identifiable as a reflection of its base.