Bruce Wayne creates Batman to strike fear into the hearts of Gotham's underworld. The costume — and the way he acts while wearing it — are meant to be as imposing and intimidating as possible. While Bruce Wayne is lighthearted and irresponsible, Batman is stoic and driven. In addition to the change in costume and personality, Bruce Wayne also changes his voice significantly to become Batman. The Dark Knight's voice is low and raspy, for both disguise and intimidation.
In keeping with the "dark" theme of the comics and the nature of bats, Batman is usually presented as operating primarily at night. After
Zero Hour, DC Comics introduced the idea of the general public believing Batman to be
urban legend; however, Batman is "outed" in the "
War Games" crossover, when his live image is broadcast over the news during a brief daytime appearance in front of a high school under siege in Gotham. In
The Long Halloween, Batman himself regards "his appearance to be more effective during the night".
The details of the Batman costume change repeatedly through the character's evolution, but the most distinctive elements remain consistent: a black scallop-hem cape, a
cowl covering most of the face featuring a pair of batlike ears, and a stylized bat emblem on the chest, plus the ever-present
utility belt. His gloves also typically feature three scallops that protrude from the sides. The most significant costume variations over the years involve the chest emblem–a yellow ellipse was added in 1964, and has come and gone since then; and the color scheme, alternately lighter colors (medium blue and light gray) or darker (black and dark gray). The length of the cowl's ears and of the cape vary greatly depending on the artist. On film, his uniform varies from its comic versions.
In his earliest appearances, Batman wears a bulletproof vest, but it was dropped soon after, in order to make the character even more human. However, later writers reintroduced the idea. To that end, in
Batman: The Dark Knight Returns, Batman explains that the bright yellow ellipse on an otherwise dark costume provides an attractive target, drawing shooters away from a headshot and to a region of his costume that can better take the blow.