"Utsāha" or dynamic energy is the "sthāyibhāva" or primary state of "vira rasa", without "utsāha" one cannot act; "Nātya Śastra" VI.66 tells us that "vira rasa" is a dynamic energy ("utsāha") which arises from various causal factors ("arthaśeśa") such as decisiveness, not giving way to depression, not being surprised or confused.A ruler is supposed to possess and the means of gaining three kinds of "shakti" (powers) viz., the powers of "mantra" (counsel), "prabhutva" (command over material resources) and "utsāha" (energy).