Assassins will kill both men and women.
"It was not irrational on her part, of course, to fear an assassination plot."
Magicians of Gor, pg. 459
"He would be merciless, and he would take no chances."
Beasts of Gor, pg. 88
"Scormus of Ar reminded me of men of the caste of Assassins, as they sometimes are, before they begin their hunt. The edge must be sharp, the resolve must be merciless, the instinct to kill must no way be blunted."
Beasts of Gor, pg. 86
Assassins must kill their friend to become an assassin.
"Training proceeds in pairs, each pair against others. Friendship is encouraged. Then, in the final training, each member of the pair must hunt the other. When on has killed one's friend, one is then likely to better understand the meaning of the black. When one has killed one's friend, then one in unlikely to find mercy in his heart for another. One is alone, with gold and steel."
Beasts of Gor, pg. 358
Assassins are loyal to secret code.
"The assassins take in lads who are perhaps characterized by little but unusual swiftness, and cunning, and strength and skill, and perhaps selfishness and greed, and, in time, transform this raw material into efficient, proud, merciless men, practitioners of a dark trade, men loyal to secret code, the content of which is something at which most men dare not guess."
Beasts of Gor, pg. 358
Assassins wear the sign of a black dagger upon their foreheads when they have been paid gold.
"When he of the Caste of Assassins has been paid gold and has received his charge, he affixes on his forehead that sign, that he may enter whatever city he pleases, that none may interfere with his work."
Assassin of Gor, pg. 7