It is said that when you break a mirror, your cosmic penance is to endure seven years of bad luck, unless you can find a way to counteract the negative effects. Thankfully, there are a few things you can do to prevent all that karmically bad juju after you break a mirror, although you might have to get a little dirty or soggy. It's still preferable to spending the rest of your seven year sentence wondering why your car keys keep breaking off in the ignition or why you keep missing the bus.
The origin of the "break a mirror, face seven years of bad luck" superstition can be traced back to the Romans, who were the first to create glass mirrors. Just because your culture invents something totally useful like a mirror doesn't mean you can't still have some irrational beliefs about its use. The Romans, along with the Greek, Chinese, African and Indian cultures, believed that a mirror had the power to confiscate part of the user's soul. If the user's reflected image became distorted in any way, this could mean a corruption of his or her soul.
To make bad matters even worse, if the user should break a mirror it would mean his or her soul would be trapped inside the Bizarro world the mirror represented. Essentially, a broken mirror created a broken soul, which in turn lead to the broken health of the unfortunate user. The Romans also believed that a person's physical body renewed itself every seven years, so under that criteria it would take seven years before the user's soul would be fully restored. Up until then, life for a mirror breaker would be one long string of unfortunate events, since he or she no longer had a healthy soul to ward off spiritual evil-doers.
Fortunately, there are also a number of rituals which are said to counteract the very bad hair day created when you break a mirror. Since the pieces of the mirror can still reflect the corrupted soul, the entire mirror should be ground into dust. No reflection, no problem. It is also suggested that after you break a mirror, you should invest in a shovel and bury the pieces under a tree during a full moon. African slaves working in America believed the bad luck could be washed away by placing the pieces in a river flowing in a southerly direction.
If you should happen to break a mirror accidentally, seven years of bad luck may not be your first concern. Wrap tape around the mirror's frame to hold the smaller fragments in place. Avoid touching the broken shards of glass without proper protection for your hands and feet. Whenever you break a mirror in a public space, you need to report the damage to an authority figure as soon as possible to prevent others from becoming injured.