Other principles and practices
Meditation or dhyana of some form is a common practice in most if not all schools of Buddhism, for the clergy if not the laity.

Central to Buddhist doctrine and practice is the law of karma and vipaka; action and its fruition, which happens within the dynamic of dependent origination (pratatya-samutpada). Actions which result in positive retribution (happiness) are defined as skillful or good, while actions that produce negative results (suffering) are called unskillful or bad actions. These actions are expressed by the way of mind, body or speech. Some actions bring instant retribution while the results of other actions may not appear until a future lifetime. Most teachers are, however, quick to point out that though it may be a result of someone's past-life karma that they suffer, this should not be used as an excuse to treat them poorly; indeed, all should help them and help to alleviate their suffering, leading to them working to alleviate their own suffering.

Rebirth, which is closely related to the law of karma. An action in this life may not give fruit or reaction until the next life time. This being said, action in a past life takes effect in this one, making a chain of existence. The full realization of the absence of an eternal self or soul (the doctrine of anatta (Pali; Sanskrit: anatman)) breaks this cycle of birth and death (samsara).