chatkain
sanatanhindusikh
shastarvidiya

Without 'Chatka', according to Sanatan Hindu Sikh tradition, a warrior is wortheless.

One present day Sanatan Hindu Sikh Shastar Vidiya exponent and former Nihang Singh from Patiala, Punjab, Bhai Ranjit Singh comments:

'The meaning of 'Chatka' is 'to kill with a single blow'. Only that warrior can do Chatka who has strength, who has 'Pentra', and who has the knowledge. He who does not know even to strike, how can he do Chatka? With the indication of the eye, Chatka (kill with one strike)! If you say this [Gatka] is like cockerels scrapping, it is not a scrap of cockerels. In front of us is our history. If our Guru Sahib [Guru Hargobind] killed Paindeh Khan he took three blows but Chatka [Killed] him in one. Whoever he killed - if he killed someone with a arrow, he did it with one arrow. With one arrow he sent them [enemies] to the next world. He did not waste his arrows by shooting them into their legs or feet or missing their target. This is meaning of Chatka [to kill, opponent quickly and cleanly].'
(Bhai Ranjit Singh, transcript of interview, 4th March 2001)

Nihang Baba Ram Singh, another practitioner of Sanatan Hindu Sikh Shastar Vidiya, names the higher Shastar Vidiya of the Akali Nihang Singhs thus:

'Then were these higher Vidiya that were called:“Vidiya of Chatka”.'
(Nihang Baba Ram Singh, transcript of interview, 16the April 1998)

Hence, the martial concept of Chatka is to kill the opponent quickly, cleanly and instantaneously at first given opportunity.