A small one-time use fetish that grants the bearer a morale bonus to a series of skill checks, ability checks, saving throws, or attack rolls. The type (e.g. Acrobatics charm, Fortitude charm, Attack charm, etc) and amount of bonus is determined when crafted but it a maximum of +2. The charm has no magical properties. Its effect is purely psychological like a placebo. Using a Shoanti charm is a free action. Once it fails, it is useless and should be discarded for fear of stale luck.
A scale to represent value of charm benefit makes sense..
Swift action to use if accessible (fetish affixed to spear head, hanging from belt, tied to gauntlet -- not tucked away).