Are targets aware they are targeted by Halfling Jinx?

Question

This questions is probably similar to witch hexes and other mind-control spells, but seems different enough to ask.

Halflings with this racial trait gain the ability to curse another creature with bad luck at will as a standard action. This curse has a range of 30 feet, and you must be able to see the target and have line of effect to it. The target gets a Will saving throw to resist this jinx (DC = 10 + 1/2 your level + your Charisma modifier). If your target makes this saving throw, it is immune to your jinx ability for 24 hours. A jinxed creature takes a –1 penalty on all saving throws. This jinx lasts for 24 hours or until you attempt to use your jinx again. A jinx is a supernatural ability, is not mind-affecting, does not allow spell resistance, and can affect any kind of creature not immune to luck effects. This replaces halfling luck.

If my halfling targets someone with the jinx, does his enemy or other observers know they are being jinxed?

Answer 1

Observers and the target typically don't know what the halfling's doing

Unless a supernatural ability's description mandates the ability's user take some perceivable action or the supernatural ability's description says the ability creates a perceivable effect, there's no indication to observers or to the ability's target that the user is doing anything except insofar as the user has apparently done nothing when the user presumably should've been able to do something.

Thus, when a halfling uses the alternate race trait halfling jinx—that is itself a supernatural ability—, neither onlookers nor the creature that must make a saving throw against the halfling's supernatural ability halfling jinx know that the halfling's jinxing a creature. In fact, they've no idea what that halfling is doing. The halfling's just there, staring off into space or whatever.

If the GM rules that supernatural abilities are close enough to spells that the general Magic rules apply to them (as this GM rules they are), then, if the target succeeds on the saving throw against the supernatural ability halfling jinx, the target "feels a hostile force or a tingle, but cannot deduce the exact nature of the attack." Further, the halfling himself knows "if a creature's saving throw succeeds against" the ability halfling jinx.