The Concise Oxford Dictionary of World Religions (1722 page)

a
a
ga

r
ja

kle
a

(i) b
janiyama, biological or hereditary constraints;
(ii) mano- or
citta-niyama
, unwilled operations of the mental order;
(iii) 
karma-niyama
, the consequences of volitional dispositions;
(iv) uti-niyama, constraints in the physical environment;
(v) 
dharma-niyama
, constraints derived from the transcendental order. From these, it will be seen that events cannot be construed as the simple working out of karma, as though all eventualities must have a preceding karmic cause.