Arthashastra
राज आवासम् अनुप्रविष्टा वा संकुलेषु राजानं हन्युः ॥
After entering into the king's (the enemy's) palace, they may kill the king in the tumult.
english translation
rAja AvAsam anupraviSTA vA saMkuleSu rAjAnaM hanyuH ॥
hk transliteration by Sanscript