The six types of cause (Wyl. rgyu drug) are the basis on which all conditioned things arise. They are:
- Acting causes (byed pa'i rgyu) are like the seed to its sprout. This is the general trait of all types of causes.
- Cooperating causes (lhan cig 'byung ba'i rgyu) are things that mutually uphold one another, like tent-poles in tipi supporting each other.
- Causes similar to their result (skal pa mnyam pa'i rgyu) when cause and effect are of similar kind, as for example, virtue arising from a virtuous frame of mind or barley growing from barley.
- Concurrent causes (mtshungs par ldan pa'i rgyu) correspond only to consciousness and mental states which are concurrent in five ways. They are a type of cooperating causes.
- Omnipresent causes (kun tu 'gro ba'i rgyu) --here "omnipresent" referring to disturbing emotions, it is just another way of talking about production by phenomena mixed with disturbing emotions.
- Causes of karmic ripening (rnam par smin pa'i rgyu) which produce pleasurable and painful experiences in samsara. They refer only to tainted virtue or nonvirtue.