I am guessing this is for some strange disadvantage with the skill, although it could just be some kind of bug. Blackjack, when attempted you do not come out of the shadows, Garrotte brings you out of the shadows.

bl someone
They aren't here.

civilized <670(100%)hp 516(100%)m 652(100%)mv 10142tnl (37.01%)> outdoor bl someone
They aren't here.

civilized <670(100%)hp 516(100%)m 652(100%)mv 10142tnl (37.01%)> outdoor garr someone
You step out of the shadows.
They aren't here.

civilized <670(100%)hp 516(100%)m 652(100%)mv 10142tnl (37.01%)> outdoor hid
You attempt to hide.

civilized <670(100%)hp 516(100%)m 652(100%)mv 10142tnl (37.01%)> outdoor garr someone
You step out of the shadows.
They aren't here.

civilized <670(100%)hp 516(100%)m 652(100%)mv 10142tnl (37.01%)> outdoor hid
You attempt to hide.