Now, Halloween superstitions are more about what people think or believe regarding the Samhain holiday. It's a little different from Halloween traditions, which are the practices and activities that people do. So here is a slightly different viewpoint on the beliefs of Halloween, based on folklore and superstitions.
Samhain is the Celtic God of Death
This is more of a modern-day misconception, but still worth mentioning because it is just so wrong. There is no Celtic god of death in the first place, and the word "samhain" roughly translates to "summer's end", which is accurate and not that mysterious.
The Dead Walk Among Us
Non-Pagans would consider this to be a silly superstition, but many people do believe this to be true. That is one of the main ideas of what Halloween is all about. As the darkness of winter approaches, the boundary between this world and the next gets thin and spirits can join the living for one night. This is the central belief of the day that leads to most of the usual traditions. A lit Jack-o-lantern will scare away bad spirits, and we dress up to hide from them.
This is also the main belief behind why so many people do Tarot readings, seances or other forms of divination on Samhain night. It's the perfect night to communicate with the dead, who are now nearby.
Black Cats are Evil
More specifically, black cats are the "familiars" of witches or devils. Not really just at Halloween, but the idea tends to come out this time of year. While some witches and Wiccans do work with animal familiars, there is no particular reason why they have to be cats nor do they have to be black.
People Tamper with Candy
Ok, this is a very modern Halloween superstition, but a common one nonetheless. No matter how many people have told you that it happens all the time, or that they "know someone" who found a razor blade in their treats, it is extremely rare. There has been decades of hype and hoaxes to lead people to believe that there is disaster waiting for them in every mini chocolate bar. The debunking site Snopes has explained it all, if you want to read more on that.
Halloween is a Witch's New Year
This belief is partially true, but since not all witches and Wiccans believe the same things nor practice the same way, it's not really a set-in-stone fact. And its usually explained in a negative way, that witches love to honor the dead or the devil on this "evil" night. That's not the point at all. It's considered the new year because of the way the light and dark cycle, and that Samhain marks the dark time of the year and the time of the final harvest. A new cycle begins after that.
Friday the 13th
And of course, some people believe that it will be doubly horrific if Halloween falls on a Friday the 13th. I'll just let you think about that one for a few minutes...