High Quality Content by WIKIPEDIA articles! The sica was a sword in Ancient Rome. It was the weapon of choice used by a gladiator called Thraex or "Thracian". It was originally depicted as a curved sword, (see the Zliten mosaic as well as numerous oil lamps) with a blade about 16-18 inches long (40 - 45 cm). The later sica blade (from late in the 1st century AD) had a sharp,almost 45 degree, bend in it. While early sicas may have been single edged, the later bent sicas were apparently double edged. The distinctive shape was designed to get around the sides of an opponent's shield, and stab or slash them in the back. Since the traex gladiator's usual opponent was the Scutum (large shield) carrying myrmillo gladiator, such a weapon as the sica was necessary to make the duel more even and exciting.