I've decided to start a Friday feature, a brief introduction to several rare or obscure proficiencies, and how they are used in the game.
Today I've selected the Non-Weapon Proficiency "Crowd-Working." It is a rogue proficiency, costing two slots, unless your character is a bard, in which case it only costs one. This means if you're a non-rogue character, it's probably going to cost you three slots. It is an unmodified charisma roll. It appeared first in the Complete Bard's Handbook, 2127 (PHBR7). It may be allowed as a bonus proficiency for characters with a bardic background and sufficient justification.
Here is the book description of the proficiency:
Almost every bard is familiar with the ways of a crowd. However, those who take crowd working learn all the tricks of the trade. Such bards are skilled at observing crowds and adjusting their performances accordingly. Any bard who is using a special ability to adjust the encounter reactions of a crowd (e.g., influence reactions) can make a crowd working proficiency check. If this check is successful, the bard can alter the reactions of the crowd by two levels instead of the typical one. If the bard or his group is soliciting money from a crowd, a successful proficiency check indicates that the bard is particularly appealing and the crowd willingly donates twice as much money as it normally would (or conditions improve one category if using the performance rules earlier in this handbook).
If used with the optional "Create Distraction" thieving ability, a successful Crowd-Working check can add a 10% bonus to a Create Distraction check. This 10% is included as the bonus when calculating the bonus for other rogues working with the distracted crowd.
Example: Doro the Whistler and Felder the Cutpurse are short on funds and decide to gather a little coinage by giving a free performance in the Market Quarter at Misty Cross. Doro rolls a successful Crowd Working check, and also rolls a successful check on his musical instrument, in this case choosing to sing a bawdy song while accompanying himself on lute rather than using his customary Whistling talent (which he usually saves for Halfling crowds, who appreciate it better.) Doro turns his showmanship up to maximum levels, intentionally trying not only to influence the crowd, but to keep them distracted from the cutpurse weaving his way through them. Since Crowd-Working already has the crowd under his sway, he gains a 10% bonus to his create distraction roll. He only needs a 45 to create a distraction, but rolls an 85, giving him a total of 95% to his create distraction. Using the rules for create distraction, this gives a bonus of 50% to Felder's pick pockets rolls, so Felder easily moves through the crowd, cutting purses and acquiring jewelry.
Doro, being one of the best bards in the city, quickly ends his song, adding that their ecstatic reaction is payment enough (because if people reach in to pay him, they will notice they are missing money), and makes himself scarce, just as the first people notice their missing pouches.