It is a Halachah l'Moshe mi'Sinai that a son may buy his Korbanos Nezirus from the money that his father set aside for his Korbanos Nezirus before he died.
If a non-Jew separates a Korban with a Neder or a Nedavah we accept the Korban from him and bring it on the Mizbe'ach.
If a child who is within a year of becoming a Gadol makes a Neder it is binding. (1)
It is a Machlokes Tana'im whether a non-Jew may pledge the Erech of a Jew. (2)
The Neder of a non-Jew is only binding if he understands the concept of a Neder. (3)
It is a Machlokes whether a Yad for a Neder that is not 'Mochi'ach' is a valid Lashon for a Neder.
R. Tarfon holds that if a person becomes a Nazir on condition he is not a Nazir. (4)
A Chacham may only release a person from his Neder if he expresses regret for making the Neder.
A person may annul the Neder of his wife, but not the Neder of his servant.
A person may protest the Nezirus of his servant. (5)
If a servant makes a Neder or Shevu'ah that will negatively affect his work for his master the servant may not keep the Neder.
R. Meir says that if a servant runs away from his master after the master protested his Nezirus he may not drink wine. (6)
R. Yosi says that the servant may drink wine because eventually he will return to his master.
Shmuel says that if the master is Mafkir his servant he goes out free and no release document is needed.
A BIT MORE
1. Some opinions hold that it is binding mid'Oraisa and some say that it is mid'Rabanan.
2. The opinion that holds that a non-Jew may pledge the Erech of a Jew holds that a Jew may not pledge the Erech of a non-Jew, while the opinion that holds that a non-Jew may not pledge the Erech of a Jew holds that a Jew may pledge the Erech of a non-Jew.
3. However for a Jew if he is a Gadol a Neder is binding even if he does not understand the concept of a Neder.
4. Even if the condition is fulfilled it is not a Nezirus according to R. Tarfon.
5. The servant may drink wine and only after he goes free should he complete his Nezirus.
6. In order to distress him so that he will return to his master.
FREEING A SERVANT
A master may not annul the Neder of his servant, however the Rambam says that if the master does annul his Neder the servant goes free and he must immediately complete his Nezirus.
Women and servants may become Nezirim. A father or husband may annul her Nezirus just as they may annul other Nedarim. A master may force his servants to drink wine but if does not force him he must keep the Nezirus. (Rambam Hilchos Nezirus 2:17)