In Raymond Chandler’s short story “Nevada Gas,” Johnny De Ruse, one of his proto-Marlowe protagonists, pays a hotel detective for answers to questions. In GUMSHOE terms, he’s clearly using the Bargaining ability. Before De Ruse gives him the dough, he extracts a promise not to tip off the man he’s investigating. A few beats later, he discovers that the house dick, Kuvalick, went straight to his target to spill the beans.
GUMSHOE handles requests for benefits other than information as spends. You spend a pool point associated with the investigative ability you’re using. You’d get the info from Kuvalick, then spend a point to get him to shut up.
De Ruse naturally is plenty steamed when he finds out that Kuvalick double-dealt him. You can expect your players to be even more annoyed than their characters if they make spends and get less than nothing for them. Yet to never permit a supporting character to betray them means that you can never use this basic genre situation.
To retain the possibility of petty sellouts in a way players find acceptable, frame it as a choice. As the PC extracts the promise of cooperation from Kuvalick, suggest, in GM authorial voice, something along the lines of “you can see the wheels turning in the backs of his eyes. Trusting him might be a crapshoot.” When the player has 2 points in Bargaining, you could indicate that 1 point lends the chance of cooperation, while 2 buys certainty. Even if the player has only 1 point, she can still decide whether spending it on an untrustworthy recipient is still worth risking. Then when the betrayal comes, the player at least made an aware choice.
(In a scenario you could easily roll randomly to determine whether your Kuvalick equivalent rats the characters out or stays bribed.)
Except in the bleakest setting, let’s say a Purist Cthulhu scenario, I’d then refund the spent point.
This uncertainty principle could extend to other Interpersonal spends, adding suspense to the proceedings. The investigator senses that a 1-point Reassurance spend might or might not keep the scared maid from staying put while you go off to find the ghoul. That the recipient of your 1-point Cop Talk might agree not to record your interaction in his notebook, and so on.
One could argue that characters ought to have Bullshit Detector in order to sense that a bribe might not stick. On the other hand, you could also say that Bargaining includes the ability to assess honesty during a Bargain, Reassurance can test whether your calming words will stick, and so on.
GUMSHOE is the groundbreaking investigative roleplaying system by Robin D. Laws that shifts the focus of play away from finding clues (or worse, not finding them), and toward interpreting clues, solving mysteries and moving the action forward. GUMSHOE powers many Pelgrane Press games, including Trail of Cthulhu, Night’s Black Agents, Esoterrorists, Ashen Stars, Mutant City Blues and Fear Itself. Learn more about how to run GUMSHOE games, and download the GUMSHOE System Reference Document to make your own GUMSHOE products under the Open Gaming License or the Creative Commons 3.0 Attribution Unported License.