I have been the DM of a wonderful group of Stack Exchange friends playing an urban fantasy campaign of D&D 5e for some time now, and a question came up in our group Discord that has got me thinking about how I should form a strategy for it.
One of my players, whose character is Sherri, has a very high Persuasion skill (+5) and has been itching for more chances to use it in-game. I'm admittedly often a bit bad at giving Sherri the chance to do so, because the player roleplays her so effectively in conversation that sometimes I just mentally skip over having them roll for whether Sherri's argument was effective. However, I want to get better about incorporating more of Sherri's Persuasion rolls and making sure she gets to use her charisma skills so that the player feels good about investing into those abilities mechanically.
The problem arises, however, when I consider what happens and how to work it into the narrative if the player roleplays an extremely effective/persuasive argument but then flubs the Persuasion roll.
For example, we recently had a situation where a kenku was spilling some information about the Evil Organization to the players and "borrowed" the cell phone of an NPC the party is attached to, then called them and mimicked that NPC's voice to lure them to a neutral location to have a conversation. At several points in the conversation the players were trying to get information out of the kenku, including making persuasive statements, where I absolutely could and should have had them roll Persuasion, Deception or Intimidation.
"Why don't we head inside to discuss this, dear?" Sherri suggests, and goes to unlock the door of the library.
"I say nothing until we have a deal. This is not from the Dreaming Brethren. This is from me." The bird blinks rapidly again. "Am in danger just for meeting you. Was not supposed to do it."
It didn't work out that way, but I had several planned routes for this encounter, some of which would have ended with the kenku fleeing if the social encounter had gone sideways or they had spooked her into thinking the party couldn't be trusted with her information. I had planned out several "persuasion points" that, if the party hit on at least one of them, would have persuaded the kenku to trust them - i.e. showing they are powerful enough to protect her, telling her she won't be harmed, not having any visible weapons, and so on. The party did well at gradually persuading the kenku that they were trustworthy and that the kenku wouldn't be harmed for bringing them what she knew. At any point during that process, however, one of the players could have roleplayed being very persuasive and hit on one of those planned "persuasion points"... but then rolled a 3 on Persuasion. I didn't have a plan for what to do if that happened. Does that mean...
- ...the character stumbled over their intended words or made a Freudian slip?
- ...the character's argument came out correctly but they accidentally did something threatening, like subconsciously drop a hand onto their weapon?
- ...the NPC misread their intentions or misunderstood their argument?
How do I work into the narrative a good argument but a bad roll?