Triskaidekaphobia may have also affected the Vikings-it is believed that Loki in the Norse pantheon was the 13th god. More specifically, Loki was believed to have engineered the murder of Balder, and was the 13th guest to arrive at the funeral. This is perhaps related to the superstition that if thirteen people gather, one of them will die in the following year.
Ancient Persians believed the twelve constellations in the Zodiac controlled the months of the year, and each ruled the earth for a thousand years at the end of which the sky and earth collapsed in chaos. Therefore, the thirteenth is identified with chaos and the reason Persians leave their houses to avoid bad luck on the thirteenth day of the Persian Calendar, a tradition called Sizdah Bedar.
However, the number 13 is not uniformly bad in the Judeo-Christian tradition. For example, the 13 attributes of God (also called the thirteen attributes of mercy) are enumerated in the Torah. Some modern Christian churches also use 13 attributes of God in sermons.
除此以外，不吉利的13还有很多传闻，包括汉莫拉比法典(code of Hummurabi)的第13条法规、十字军东征时的13圆桌骑士以及Friday the 13th（十三号星期五）等等。不过，也不是所有基督教传统的国家都认为13是不吉利的，在某些基督教祭典中还有13信条的仪式。