It is believed that during the Nymph week the wood- and water-nymphs and other similar creatures (ruaslyas) run wild day and night. In that time they work mischief on the people who enter their dwellings. Their flower dittany, called also wood-nymph flower, grows in the glades. It was believed to heal different incurable illnesses, especially if picked in the night before Spasovden (Midsummer Day) or another day from the Nymph week.

Wood-nymphs were believed to be very sensitive to smells – herbs and flowers. That is why the superstitious wore in their pockets, in their sashes or on their heads wormwood, dittany, lovage or walnut leaves.

In the Nymph week special games, called rusalii, are organized. They are played only by men who are skillful and experienced in them. If a man joins such a team (rusaliiska druzhina), he must be a part of it for at least 10-11 years. The leader of the team is called vataf and inherits this position from his father. Every man in this team has a long staff with trinkets on it. They wear ordinary clothes, with herbal garlands on their fur caps, spurs on their feet or trinkets which make noise when dancing. The leader (vatafin) carries a white flag – a staff with a piece of white cloth which has magic herbs sewn to it.

The participants go out for the games on Monday or just after Spasovden and go around the near villages for a week. For the games they receive gifts, money and food. Some games are meant to cure illnesses caused by nymphs. The games have the nature of a ritual and complex magic and a quite fast and exhausting. They play around the ill person taken out in a rug jumping over him/her and tossing him/her with the rug. After that fast dances are played around a pot full of herbs. When, in the speed of the dance, the pot shatters at the blow of the staff, the ill one gets up and runs away “already in full health”.