Laos is predominantly Buddhist, but similarly to some other Asian countries, some ancient pagan traditions such as Baci or Soo Kwan are still in place.

Some Lao people believe that the human body consists of 32 organs, and each has its spirit or Kwan. If the spirit leaves the body for some reason, one may suffer from illness, spiritual or physical weakness, or bad luck. There are many reasons why one's spirit may leave the body—the transition between years, giving birth to a baby, the death of a relative, and so on.

Baci is often held on many occasions like births and marriages and also entering the monkhood, departing, returning and welcoming or bidding throughout the year but it's also regularly held on the first day of the new year.

The ceremony typically lasts for about an hour. An elderly person or a monk takes a white cotton string and ties it around the wrist of the participant. Strings may also be tied around the wrists of an entire family during the New Years celebration, bringing everyone good luck and health for the upcoming year. Participants sometimes hold a blank note or some other symbolic object in their palms.

Tourists may visit the ceremony on different occasions, but to become a participant, the best time is Lao New Years in April.