Friday the 13th is considered superstitious and unlucky primarily because it combines two long-standing cultural taboos: the number 13 and the day Friday. The number 13 is often viewed as unlucky in many cultures due to historical and mythological reasons, such as Judas being the 13th guest at the Last Supper before Jesus's crucifixion and the Norse myth where Loki, the 13th guest, caused chaos leading to Balder's death. Fridays have also been deemed unlucky in Christian tradition due to several misfortunes associated with the day, including the crucifixion of Jesus, Adam and Eve's original sin, and other biblical calamities. The combination of these two elements (Friday and the 13th) intensified the superstition around this date. The fear or phobia of this specific day is so notable it has been named paraskevidekatriaphobia. The superstition gained modern prominence in the 19th century and was further popularized by 20th-century media like horror films and literature. Thus, Friday the 13th's superstition arises from a blend of ancient myths, religious beliefs, and cultural traditions holding the number 13 and Fridays to be unlucky in different ways, amplified when they coincide.